| Message ID | 20191024050829.4517-1-zhenyuw@linux.intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | VFIO mdev aggregated resources handling | expand |
On Thu, 24 Oct 2019 13:08:23 +0800 Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > Hi, > > This is a refresh for previous send of this series. I got impression that > some SIOV drivers would still deploy their own create and config method so > stopped effort on this. But seems this would still be useful for some other > SIOV driver which may simply want capability to aggregate resources. So here's > refreshed series. > > Current mdev device create interface depends on fixed mdev type, which get uuid > from user to create instance of mdev device. If user wants to use customized > number of resource for mdev device, then only can create new mdev type for that > which may not be flexible. This requirement comes not only from to be able to > allocate flexible resources for KVMGT, but also from Intel scalable IO > virtualization which would use vfio/mdev to be able to allocate arbitrary > resources on mdev instance. More info on [1] [2] [3]. > > To allow to create user defined resources for mdev, it trys to extend mdev > create interface by adding new "aggregate=xxx" parameter following UUID, for > target mdev type if aggregation is supported, it can create new mdev device > which contains resources combined by number of instances, e.g > > echo "<uuid>,aggregate=10" > create > > VM manager e.g libvirt can check mdev type with "aggregation" attribute which > can support this setting. If no "aggregation" attribute found for mdev type, > previous behavior is still kept for one instance allocation. And new sysfs > attribute "aggregated_instances" is created for each mdev device to show allocated number. Given discussions we've had recently around libvirt interacting with mdev, I think that libvirt would rather have an abstract interface via mdevctl[1]. Therefore can you evaluate how mdevctl would support this creation extension? It seems like it would fit within the existing mdev and mdevctl framework if aggregation were simply a sysfs attribute for the device. For example, the mdevctl steps might look like this: mdevctl define -u UUID -p PARENT -t TYPE mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 mdevctl start -u UUID When mdevctl starts the mdev, it will first create it using the existing mechanism, then apply aggregation attribute, which can consume the necessary additional instances from the parent device, or return an error, which would unwind and return a failure code to the caller (libvirt). I think the vendor driver would then have freedom to decide when the attribute could be modified, for instance it would be entirely reasonable to return -EBUSY if the user attempts to modify the attribute while the mdev device is in-use. Effectively aggregation simply becomes a standardized attribute with common meaning. Thoughts? [cc libvirt folks for their impression] Thanks, Alex [1] https://github.com/mdevctl/mdevctl > References: > [1] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification > [2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > Zhenyu Wang (6): > vfio/mdev: Add new "aggregate" parameter for mdev create > vfio/mdev: Add "aggregation" attribute for supported mdev type > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > device > Documentation/driver-api/vfio-mediated-device.rst: Update for > vfio/mdev aggregation support > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > aggregation support > drm/i915/gvt: Add new type with aggregation support > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > drivers/vfio/mdev/mdev_private.h | 6 +- > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > include/linux/mdev.h | 19 +++++ > 10 files changed, 294 insertions(+), 17 deletions(-) >
On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > On Thu, 24 Oct 2019 13:08:23 +0800 > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > Hi, > > > > This is a refresh for previous send of this series. I got impression that > > some SIOV drivers would still deploy their own create and config method so > > stopped effort on this. But seems this would still be useful for some other > > SIOV driver which may simply want capability to aggregate resources. So here's > > refreshed series. > > > > Current mdev device create interface depends on fixed mdev type, which get uuid > > from user to create instance of mdev device. If user wants to use customized > > number of resource for mdev device, then only can create new mdev type for that > > which may not be flexible. This requirement comes not only from to be able to > > allocate flexible resources for KVMGT, but also from Intel scalable IO > > virtualization which would use vfio/mdev to be able to allocate arbitrary > > resources on mdev instance. More info on [1] [2] [3]. > > > > To allow to create user defined resources for mdev, it trys to extend mdev > > create interface by adding new "aggregate=xxx" parameter following UUID, for > > target mdev type if aggregation is supported, it can create new mdev device > > which contains resources combined by number of instances, e.g > > > > echo "<uuid>,aggregate=10" > create > > > > VM manager e.g libvirt can check mdev type with "aggregation" attribute which > > can support this setting. If no "aggregation" attribute found for mdev type, > > previous behavior is still kept for one instance allocation. And new sysfs > > attribute "aggregated_instances" is created for each mdev device to show allocated number. > > Given discussions we've had recently around libvirt interacting with > mdev, I think that libvirt would rather have an abstract interface via > mdevctl[1]. Therefore can you evaluate how mdevctl would support this > creation extension? It seems like it would fit within the existing > mdev and mdevctl framework if aggregation were simply a sysfs attribute > for the device. For example, the mdevctl steps might look like this: > > mdevctl define -u UUID -p PARENT -t TYPE > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > mdevctl start -u UUID > > When mdevctl starts the mdev, it will first create it using the > existing mechanism, then apply aggregation attribute, which can consume > the necessary additional instances from the parent device, or return an > error, which would unwind and return a failure code to the caller > (libvirt). I think the vendor driver would then have freedom to decide > when the attribute could be modified, for instance it would be entirely > reasonable to return -EBUSY if the user attempts to modify the > attribute while the mdev device is in-use. Effectively aggregation > simply becomes a standardized attribute with common meaning. Thoughts? > [cc libvirt folks for their impression] Thanks, I think one problem is that before mdevctl start to create mdev you don't know what vendor attributes are, as we apply mdev attributes after create. You may need some lookup depending on parent.. I think making aggregation like other vendor attribute for mdev might be the simplest way, but do we want to define its behavior in formal? e.g like previous discussed it should show maxium instances for aggregation, etc. The behavior change for driver is that previously aggregation is handled at create time, but for sysfs attr it should handle any resource allocation before it's really in-use. I think some SIOV driver which already requires some specific config should be ok, but not sure for other driver which might not be explored in this before. Would that be a problem? Kevin? Thanks > > Alex > > [1] https://github.com/mdevctl/mdevctl > > > References: > > [1] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification > > [2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > Zhenyu Wang (6): > > vfio/mdev: Add new "aggregate" parameter for mdev create > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > device > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > vfio/mdev aggregation support > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > aggregation support > > drm/i915/gvt: Add new type with aggregation support > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > drivers/vfio/mdev/mdev_private.h | 6 +- > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > include/linux/mdev.h | 19 +++++ > > 10 files changed, 294 insertions(+), 17 deletions(-) > > >
On Wed, 6 Nov 2019 12:20:31 +0800 Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > > On Thu, 24 Oct 2019 13:08:23 +0800 > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > Hi, > > > > > > This is a refresh for previous send of this series. I got impression that > > > some SIOV drivers would still deploy their own create and config method so > > > stopped effort on this. But seems this would still be useful for some other > > > SIOV driver which may simply want capability to aggregate resources. So here's > > > refreshed series. > > > > > > Current mdev device create interface depends on fixed mdev type, which get uuid > > > from user to create instance of mdev device. If user wants to use customized > > > number of resource for mdev device, then only can create new mdev type for that > > > which may not be flexible. This requirement comes not only from to be able to > > > allocate flexible resources for KVMGT, but also from Intel scalable IO > > > virtualization which would use vfio/mdev to be able to allocate arbitrary > > > resources on mdev instance. More info on [1] [2] [3]. > > > > > > To allow to create user defined resources for mdev, it trys to extend mdev > > > create interface by adding new "aggregate=xxx" parameter following UUID, for > > > target mdev type if aggregation is supported, it can create new mdev device > > > which contains resources combined by number of instances, e.g > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" attribute which > > > can support this setting. If no "aggregation" attribute found for mdev type, > > > previous behavior is still kept for one instance allocation. And new sysfs > > > attribute "aggregated_instances" is created for each mdev device to show allocated number. > > > > Given discussions we've had recently around libvirt interacting with > > mdev, I think that libvirt would rather have an abstract interface via > > mdevctl[1]. Therefore can you evaluate how mdevctl would support this > > creation extension? It seems like it would fit within the existing > > mdev and mdevctl framework if aggregation were simply a sysfs attribute > > for the device. For example, the mdevctl steps might look like this: > > > > mdevctl define -u UUID -p PARENT -t TYPE > > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > > mdevctl start -u UUID > > > > When mdevctl starts the mdev, it will first create it using the > > existing mechanism, then apply aggregation attribute, which can consume > > the necessary additional instances from the parent device, or return an > > error, which would unwind and return a failure code to the caller > > (libvirt). I think the vendor driver would then have freedom to decide > > when the attribute could be modified, for instance it would be entirely > > reasonable to return -EBUSY if the user attempts to modify the > > attribute while the mdev device is in-use. Effectively aggregation > > simply becomes a standardized attribute with common meaning. Thoughts? > > [cc libvirt folks for their impression] Thanks, > > I think one problem is that before mdevctl start to create mdev you > don't know what vendor attributes are, as we apply mdev attributes > after create. You may need some lookup depending on parent.. I think > making aggregation like other vendor attribute for mdev might be the > simplest way, but do we want to define its behavior in formal? e.g > like previous discussed it should show maxium instances for aggregation, etc. Yes, we'd still want to standardize how we enable and discover aggregation since we expect multiple users. Even if libvirt were to use mdevctl as it's mdev interface, higher level tools should have an introspection mechanism available. Possibly the sysfs interfaces proposed in this series remains largely the same, but I think perhaps the implementation of them moves out to the vendor driver. In fact, perhaps the only change to mdev core is to define the standard. For example, the "aggregation" attribute on the type is potentially simply a defined, optional, per type attribute, similar to "name" and "description". For "aggregated_instances" we already have the mdev_attr_groups of the mdev_parent_ops, we could define an attribute_group with .name = "mdev" as a set of standardized attributes, such that vendors could provide both their own vendor specific attributes and per device attributes with a common meaning and semantic defined in the mdev ABI. > The behavior change for driver is that previously aggregation is > handled at create time, but for sysfs attr it should handle any > resource allocation before it's really in-use. I think some SIOV > driver which already requires some specific config should be ok, > but not sure for other driver which might not be explored in this before. > Would that be a problem? Kevin? Right, I'm assuming the aggregation could be modified until the device is actually opened, the driver can nak the aggregation request by returning an errno to the attribute write. I'm trying to anticipate whether this introduces new complications, for instances races with contiguous allocations. I think these seem solvable within the vendor drivers, but please note it if I'm wrong. Thanks, Alex
On Wed, 6 Nov 2019 11:44:40 -0700 Alex Williamson <alex.williamson@redhat.com> wrote: > On Wed, 6 Nov 2019 12:20:31 +0800 > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > > > On Thu, 24 Oct 2019 13:08:23 +0800 > > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > > > Hi, > > > > > > > > This is a refresh for previous send of this series. I got impression that > > > > some SIOV drivers would still deploy their own create and config method so > > > > stopped effort on this. But seems this would still be useful for some other > > > > SIOV driver which may simply want capability to aggregate resources. So here's > > > > refreshed series. > > > > > > > > Current mdev device create interface depends on fixed mdev type, which get uuid > > > > from user to create instance of mdev device. If user wants to use customized > > > > number of resource for mdev device, then only can create new mdev type for that > > > > which may not be flexible. This requirement comes not only from to be able to > > > > allocate flexible resources for KVMGT, but also from Intel scalable IO > > > > virtualization which would use vfio/mdev to be able to allocate arbitrary > > > > resources on mdev instance. More info on [1] [2] [3]. > > > > > > > > To allow to create user defined resources for mdev, it trys to extend mdev > > > > create interface by adding new "aggregate=xxx" parameter following UUID, for > > > > target mdev type if aggregation is supported, it can create new mdev device > > > > which contains resources combined by number of instances, e.g > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" attribute which > > > > can support this setting. If no "aggregation" attribute found for mdev type, > > > > previous behavior is still kept for one instance allocation. And new sysfs > > > > attribute "aggregated_instances" is created for each mdev device to show allocated number. > > > > > > Given discussions we've had recently around libvirt interacting with > > > mdev, I think that libvirt would rather have an abstract interface via > > > mdevctl[1]. Therefore can you evaluate how mdevctl would support this > > > creation extension? It seems like it would fit within the existing > > > mdev and mdevctl framework if aggregation were simply a sysfs attribute > > > for the device. For example, the mdevctl steps might look like this: > > > > > > mdevctl define -u UUID -p PARENT -t TYPE > > > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > > > mdevctl start -u UUID > > > > > > When mdevctl starts the mdev, it will first create it using the > > > existing mechanism, then apply aggregation attribute, which can consume > > > the necessary additional instances from the parent device, or return an > > > error, which would unwind and return a failure code to the caller > > > (libvirt). I think the vendor driver would then have freedom to decide > > > when the attribute could be modified, for instance it would be entirely > > > reasonable to return -EBUSY if the user attempts to modify the > > > attribute while the mdev device is in-use. Effectively aggregation > > > simply becomes a standardized attribute with common meaning. Thoughts? > > > [cc libvirt folks for their impression] Thanks, > > > > I think one problem is that before mdevctl start to create mdev you > > don't know what vendor attributes are, as we apply mdev attributes > > after create. You may need some lookup depending on parent.. I think > > making aggregation like other vendor attribute for mdev might be the > > simplest way, but do we want to define its behavior in formal? e.g > > like previous discussed it should show maxium instances for aggregation, etc. > > Yes, we'd still want to standardize how we enable and discover > aggregation since we expect multiple users. Even if libvirt were to > use mdevctl as it's mdev interface, higher level tools should have an > introspection mechanism available. Possibly the sysfs interfaces > proposed in this series remains largely the same, but I think perhaps > the implementation of them moves out to the vendor driver. In fact, > perhaps the only change to mdev core is to define the standard. For > example, the "aggregation" attribute on the type is potentially simply > a defined, optional, per type attribute, similar to "name" and > "description". For "aggregated_instances" we already have the > mdev_attr_groups of the mdev_parent_ops, we could define an > attribute_group with .name = "mdev" as a set of standardized > attributes, such that vendors could provide both their own vendor > specific attributes and per device attributes with a common meaning and > semantic defined in the mdev ABI. +1 to standardizing this. While not every vendor driver will support aggregation, providing a common infrastructure to ensure those that do use the same approach is a good idea. > > > The behavior change for driver is that previously aggregation is > > handled at create time, but for sysfs attr it should handle any > > resource allocation before it's really in-use. I think some SIOV > > driver which already requires some specific config should be ok, > > but not sure for other driver which might not be explored in this before. > > Would that be a problem? Kevin? > > Right, I'm assuming the aggregation could be modified until the device > is actually opened, the driver can nak the aggregation request by > returning an errno to the attribute write. I'm trying to anticipate > whether this introduces new complications, for instances races with > contiguous allocations. I think these seem solvable within the vendor > drivers, but please note it if I'm wrong. Thanks, > > Alex FWIW, the ap driver does this post-creation configuration stuff already. The intended workflow is create->add adapters/domains->start vm with assigned device. Do we want to do some standardization as to how post-creation configuration is supposed to work (like, at which point in time is it fine to manipulate the attribute)? I'm not sure how much of this is vendor-driver specific.
Hi, > -----Original Message----- > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On Behalf > Of Zhenyu Wang > Sent: Thursday, October 24, 2019 12:08 AM > To: kvm@vger.kernel.org > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > kevin.tian@intel.com; cohuck@redhat.com > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > Hi, > > This is a refresh for previous send of this series. I got impression that some > SIOV drivers would still deploy their own create and config method so stopped > effort on this. But seems this would still be useful for some other SIOV driver > which may simply want capability to aggregate resources. So here's refreshed > series. > > Current mdev device create interface depends on fixed mdev type, which get > uuid from user to create instance of mdev device. If user wants to use > customized number of resource for mdev device, then only can create new Can you please give an example of 'resource'? When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'. > mdev type for that which may not be flexible. This requirement comes not only > from to be able to allocate flexible resources for KVMGT, but also from Intel > scalable IO virtualization which would use vfio/mdev to be able to allocate > arbitrary resources on mdev instance. More info on [1] [2] [3]. > > To allow to create user defined resources for mdev, it trys to extend mdev > create interface by adding new "aggregate=xxx" parameter following UUID, for > target mdev type if aggregation is supported, it can create new mdev device > which contains resources combined by number of instances, e.g > > echo "<uuid>,aggregate=10" > create > > VM manager e.g libvirt can check mdev type with "aggregation" attribute > which can support this setting. If no "aggregation" attribute found for mdev > type, previous behavior is still kept for one instance allocation. And new sysfs > attribute "aggregated_instances" is created for each mdev device to show > allocated number. > > References: > [1] https://software.intel.com/en-us/download/intel-virtualization-technology- > for-directed-io-architecture-specification > [2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization- > technical-specification > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > Zhenyu Wang (6): > vfio/mdev: Add new "aggregate" parameter for mdev create > vfio/mdev: Add "aggregation" attribute for supported mdev type > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > device > Documentation/driver-api/vfio-mediated-device.rst: Update for > vfio/mdev aggregation support > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > aggregation support > drm/i915/gvt: Add new type with aggregation support > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > drivers/vfio/mdev/mdev_private.h | 6 +- > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > include/linux/mdev.h | 19 +++++ > 10 files changed, 294 insertions(+), 17 deletions(-) > > -- > 2.24.0.rc0
On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > Hi, > > > -----Original Message----- > > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On Behalf > > Of Zhenyu Wang > > Sent: Thursday, October 24, 2019 12:08 AM > > To: kvm@vger.kernel.org > > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > kevin.tian@intel.com; cohuck@redhat.com > > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > > > Hi, > > > > This is a refresh for previous send of this series. I got impression that some > > SIOV drivers would still deploy their own create and config method so stopped > > effort on this. But seems this would still be useful for some other SIOV driver > > which may simply want capability to aggregate resources. So here's refreshed > > series. > > > > Current mdev device create interface depends on fixed mdev type, which get > > uuid from user to create instance of mdev device. If user wants to use > > customized number of resource for mdev device, then only can create new > Can you please give an example of 'resource'? > When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'. The resource is vendor device specific, in SIOV spec there's ADI (Assignable Device Interface) definition which could be e.g queue for net device, context for gpu, etc. I just named this interface as 'aggregate' for aggregation purpose, it's not used in spec doc. Thanks > > > mdev type for that which may not be flexible. This requirement comes not only > > from to be able to allocate flexible resources for KVMGT, but also from Intel > > scalable IO virtualization which would use vfio/mdev to be able to allocate > > arbitrary resources on mdev instance. More info on [1] [2] [3]. > > > > To allow to create user defined resources for mdev, it trys to extend mdev > > create interface by adding new "aggregate=xxx" parameter following UUID, for > > target mdev type if aggregation is supported, it can create new mdev device > > which contains resources combined by number of instances, e.g > > > > echo "<uuid>,aggregate=10" > create > > > > VM manager e.g libvirt can check mdev type with "aggregation" attribute > > which can support this setting. If no "aggregation" attribute found for mdev > > type, previous behavior is still kept for one instance allocation. And new sysfs > > attribute "aggregated_instances" is created for each mdev device to show > > allocated number. > > > > References: > > [1] https://software.intel.com/en-us/download/intel-virtualization-technology- > > for-directed-io-architecture-specification > > [2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization- > > technical-specification > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > Zhenyu Wang (6): > > vfio/mdev: Add new "aggregate" parameter for mdev create > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > device > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > vfio/mdev aggregation support > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > aggregation support > > drm/i915/gvt: Add new type with aggregation support > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > drivers/vfio/mdev/mdev_private.h | 6 +- > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > include/linux/mdev.h | 19 +++++ > > 10 files changed, 294 insertions(+), 17 deletions(-) > > > > -- > > 2.24.0.rc0 >
> From: Alex Williamson > Sent: Thursday, November 7, 2019 2:45 AM > > On Wed, 6 Nov 2019 12:20:31 +0800 > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > > > On Thu, 24 Oct 2019 13:08:23 +0800 > > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > > > Hi, > > > > > > > > This is a refresh for previous send of this series. I got impression that > > > > some SIOV drivers would still deploy their own create and config > method so > > > > stopped effort on this. But seems this would still be useful for some > other > > > > SIOV driver which may simply want capability to aggregate resources. > So here's > > > > refreshed series. > > > > > > > > Current mdev device create interface depends on fixed mdev type, > which get uuid > > > > from user to create instance of mdev device. If user wants to use > customized > > > > number of resource for mdev device, then only can create new mdev > type for that > > > > which may not be flexible. This requirement comes not only from to > be able to > > > > allocate flexible resources for KVMGT, but also from Intel scalable IO > > > > virtualization which would use vfio/mdev to be able to allocate > arbitrary > > > > resources on mdev instance. More info on [1] [2] [3]. > > > > > > > > To allow to create user defined resources for mdev, it trys to extend > mdev > > > > create interface by adding new "aggregate=xxx" parameter following > UUID, for > > > > target mdev type if aggregation is supported, it can create new mdev > device > > > > which contains resources combined by number of instances, e.g > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > attribute which > > > > can support this setting. If no "aggregation" attribute found for mdev > type, > > > > previous behavior is still kept for one instance allocation. And new > sysfs > > > > attribute "aggregated_instances" is created for each mdev device to > show allocated number. > > > > > > Given discussions we've had recently around libvirt interacting with > > > mdev, I think that libvirt would rather have an abstract interface via > > > mdevctl[1]. Therefore can you evaluate how mdevctl would support > this > > > creation extension? It seems like it would fit within the existing > > > mdev and mdevctl framework if aggregation were simply a sysfs > attribute > > > for the device. For example, the mdevctl steps might look like this: > > > > > > mdevctl define -u UUID -p PARENT -t TYPE > > > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > > > mdevctl start -u UUID Hi, Alex, can you elaborate why a sysfs attribute is more friendly to mdevctl? what is the complexity if having mdevctl to pass additional parameter at creation time as this series originally proposed? Just want to clearly understand the limitation of the parameter way. :-) > > > > > > When mdevctl starts the mdev, it will first create it using the > > > existing mechanism, then apply aggregation attribute, which can > consume > > > the necessary additional instances from the parent device, or return an > > > error, which would unwind and return a failure code to the caller > > > (libvirt). I think the vendor driver would then have freedom to decide > > > when the attribute could be modified, for instance it would be entirely > > > reasonable to return -EBUSY if the user attempts to modify the > > > attribute while the mdev device is in-use. Effectively aggregation > > > simply becomes a standardized attribute with common meaning. > Thoughts? > > > [cc libvirt folks for their impression] Thanks, > > > > I think one problem is that before mdevctl start to create mdev you > > don't know what vendor attributes are, as we apply mdev attributes > > after create. You may need some lookup depending on parent.. I think > > making aggregation like other vendor attribute for mdev might be the > > simplest way, but do we want to define its behavior in formal? e.g > > like previous discussed it should show maxium instances for aggregation, > etc. > > Yes, we'd still want to standardize how we enable and discover > aggregation since we expect multiple users. Even if libvirt were to > use mdevctl as it's mdev interface, higher level tools should have an > introspection mechanism available. Possibly the sysfs interfaces > proposed in this series remains largely the same, but I think perhaps > the implementation of them moves out to the vendor driver. In fact, > perhaps the only change to mdev core is to define the standard. For > example, the "aggregation" attribute on the type is potentially simply > a defined, optional, per type attribute, similar to "name" and > "description". For "aggregated_instances" we already have the > mdev_attr_groups of the mdev_parent_ops, we could define an > attribute_group with .name = "mdev" as a set of standardized > attributes, such that vendors could provide both their own vendor > specific attributes and per device attributes with a common meaning and > semantic defined in the mdev ABI. such standardization sounds good. > > > The behavior change for driver is that previously aggregation is > > handled at create time, but for sysfs attr it should handle any > > resource allocation before it's really in-use. I think some SIOV > > driver which already requires some specific config should be ok, > > but not sure for other driver which might not be explored in this before. > > Would that be a problem? Kevin? > > Right, I'm assuming the aggregation could be modified until the device > is actually opened, the driver can nak the aggregation request by > returning an errno to the attribute write. I'm trying to anticipate > whether this introduces new complications, for instances races with > contiguous allocations. I think these seem solvable within the vendor > drivers, but please note it if I'm wrong. Thanks, > So far I didn't see a problem with this way. Regarding to contiguous allocations, ideally it should be fine as long as aggregation paths are properly locked similar as creation paths when allocating resources. It will introduce some additional work in vendor driver but such overhead is worthy if it leads to cleaner uapi. There is one open though. In concept the aggregation feature can be used for both increasing and decreasing the resource when exposing as a sysfs attribute, any time when the device is not in-use. Increasing resource is possibly fine, but I'm not sure about decreasing resource. Is there any vendor driver which cannot afford resource decrease once it has ever been used (after deassignment), or require at least an explicit reset before decrease? If yes, how do we report such special requirement (only-once, multiple-times, multiple-times- before-1st-usage) to user space? It's sort of like what Cornelia commented about standardization of post-creation resource configuration. If it may end up to be a complex story (or at least take time to understand/standardize all kinds of requirements), does it still make sense to support creation-time parameter as a quick-path for this aggregation feature? :-) Thanks Kevin
On Fri, 15 Nov 2019 04:24:35 +0000 "Tian, Kevin" <kevin.tian@intel.com> wrote: > > From: Alex Williamson > > Sent: Thursday, November 7, 2019 2:45 AM > > > > On Wed, 6 Nov 2019 12:20:31 +0800 > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > > > > On Thu, 24 Oct 2019 13:08:23 +0800 > > > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > > > > > Hi, > > > > > > > > > > This is a refresh for previous send of this series. I got impression that > > > > > some SIOV drivers would still deploy their own create and config > > method so > > > > > stopped effort on this. But seems this would still be useful for some > > other > > > > > SIOV driver which may simply want capability to aggregate resources. > > So here's > > > > > refreshed series. > > > > > > > > > > Current mdev device create interface depends on fixed mdev type, > > which get uuid > > > > > from user to create instance of mdev device. If user wants to use > > customized > > > > > number of resource for mdev device, then only can create new mdev > > type for that > > > > > which may not be flexible. This requirement comes not only from to > > be able to > > > > > allocate flexible resources for KVMGT, but also from Intel scalable IO > > > > > virtualization which would use vfio/mdev to be able to allocate > > arbitrary > > > > > resources on mdev instance. More info on [1] [2] [3]. > > > > > > > > > > To allow to create user defined resources for mdev, it trys to extend > > mdev > > > > > create interface by adding new "aggregate=xxx" parameter following > > UUID, for > > > > > target mdev type if aggregation is supported, it can create new mdev > > device > > > > > which contains resources combined by number of instances, e.g > > > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > attribute which > > > > > can support this setting. If no "aggregation" attribute found for mdev > > type, > > > > > previous behavior is still kept for one instance allocation. And new > > sysfs > > > > > attribute "aggregated_instances" is created for each mdev device to > > show allocated number. > > > > > > > > Given discussions we've had recently around libvirt interacting with > > > > mdev, I think that libvirt would rather have an abstract interface via > > > > mdevctl[1]. Therefore can you evaluate how mdevctl would support > > this > > > > creation extension? It seems like it would fit within the existing > > > > mdev and mdevctl framework if aggregation were simply a sysfs > > attribute > > > > for the device. For example, the mdevctl steps might look like this: > > > > > > > > mdevctl define -u UUID -p PARENT -t TYPE > > > > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > > > > mdevctl start -u UUID > > Hi, Alex, can you elaborate why a sysfs attribute is more friendly > to mdevctl? what is the complexity if having mdevctl to pass > additional parameter at creation time as this series originally > proposed? Just want to clearly understand the limitation of the > parameter way. :-) We could also flip this question around, vfio-ap already uses sysfs to finish composing a device after it's created, therefore why shouldn't aggregation use this existing mechanism. Extending the creation interface is a more fundamental change than simply standardizing an optional sysfs namespace entry. > > > > > > > > When mdevctl starts the mdev, it will first create it using the > > > > existing mechanism, then apply aggregation attribute, which can > > consume > > > > the necessary additional instances from the parent device, or return an > > > > error, which would unwind and return a failure code to the caller > > > > (libvirt). I think the vendor driver would then have freedom to decide > > > > when the attribute could be modified, for instance it would be entirely > > > > reasonable to return -EBUSY if the user attempts to modify the > > > > attribute while the mdev device is in-use. Effectively aggregation > > > > simply becomes a standardized attribute with common meaning. > > Thoughts? > > > > [cc libvirt folks for their impression] Thanks, > > > > > > I think one problem is that before mdevctl start to create mdev you > > > don't know what vendor attributes are, as we apply mdev attributes > > > after create. You may need some lookup depending on parent.. I think > > > making aggregation like other vendor attribute for mdev might be the > > > simplest way, but do we want to define its behavior in formal? e.g > > > like previous discussed it should show maxium instances for aggregation, > > etc. > > > > Yes, we'd still want to standardize how we enable and discover > > aggregation since we expect multiple users. Even if libvirt were to > > use mdevctl as it's mdev interface, higher level tools should have an > > introspection mechanism available. Possibly the sysfs interfaces > > proposed in this series remains largely the same, but I think perhaps > > the implementation of them moves out to the vendor driver. In fact, > > perhaps the only change to mdev core is to define the standard. For > > example, the "aggregation" attribute on the type is potentially simply > > a defined, optional, per type attribute, similar to "name" and > > "description". For "aggregated_instances" we already have the > > mdev_attr_groups of the mdev_parent_ops, we could define an > > attribute_group with .name = "mdev" as a set of standardized > > attributes, such that vendors could provide both their own vendor > > specific attributes and per device attributes with a common meaning and > > semantic defined in the mdev ABI. > > such standardization sounds good. > > > > > > The behavior change for driver is that previously aggregation is > > > handled at create time, but for sysfs attr it should handle any > > > resource allocation before it's really in-use. I think some SIOV > > > driver which already requires some specific config should be ok, > > > but not sure for other driver which might not be explored in this before. > > > Would that be a problem? Kevin? > > > > Right, I'm assuming the aggregation could be modified until the device > > is actually opened, the driver can nak the aggregation request by > > returning an errno to the attribute write. I'm trying to anticipate > > whether this introduces new complications, for instances races with > > contiguous allocations. I think these seem solvable within the vendor > > drivers, but please note it if I'm wrong. Thanks, > > > > So far I didn't see a problem with this way. Regarding to contiguous > allocations, ideally it should be fine as long as aggregation paths are > properly locked similar as creation paths when allocating resources. > It will introduce some additional work in vendor driver but such > overhead is worthy if it leads to cleaner uapi. > > There is one open though. In concept the aggregation feature can > be used for both increasing and decreasing the resource when > exposing as a sysfs attribute, any time when the device is not in-use. > Increasing resource is possibly fine, but I'm not sure about decreasing > resource. Is there any vendor driver which cannot afford resource > decrease once it has ever been used (after deassignment), or require > at least an explicit reset before decrease? If yes, how do we report > such special requirement (only-once, multiple-times, multiple-times- > before-1st-usage) to user space? It seems like a sloppy vendor driver that couldn't return a device to a post-creation state, ie. drop and re-initialize the aggregation state. Userspace would always need to handle an aggregation failure, there might be multiple processes attempting to allocate resources simultaneously or the user might simply be requesting more resources than available. The vendor driver should make a reasonable attempt to satisfy the user request or else an insufficient resource error may appear at the application. vfio-mdev devices should always be reset before and after usage. > It's sort of like what Cornelia commented about standardization > of post-creation resource configuration. If it may end up to be > a complex story (or at least take time to understand/standardize > all kinds of requirements), does it still make sense to support > creation-time parameter as a quick-path for this aggregation feature? :-) We're not going to do both, right? We likely lock ourselves into one schema when we do it. Not only is the sysfs approach already in use in vfio-ap, but it seems more flexible. Above you raise the issue of dynamically resizing the aggregation between uses. We can't do that with only a creation-time parameter. With a sysfs parameter the vendor driver can nak changes, allow changes when idle, potentially even allow changes while in use. Connie essentially brings up the question of how we can introspect sysfs attribute, which is a big question. Perhaps we can nibble off a piece of that question by starting with a namespace per attribute. For instance, rather than doing: echo 2 > /sys/bus/mdev/devices/UUID/mdev/aggregation We could do: echo 2 > /sys/bus/mdev/devices/UUID/mdev/aggregation/value This allows us the whole mdev/aggregation/* namespace to describe other attributes to expose aspects of the aggregation support. Thanks, Alex
> From: Alex Williamson > Sent: Wednesday, November 20, 2019 6:58 AM > > On Fri, 15 Nov 2019 04:24:35 +0000 > "Tian, Kevin" <kevin.tian@intel.com> wrote: > > > > From: Alex Williamson > > > Sent: Thursday, November 7, 2019 2:45 AM > > > > > > On Wed, 6 Nov 2019 12:20:31 +0800 > > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > > > On 2019.11.05 14:10:42 -0700, Alex Williamson wrote: > > > > > On Thu, 24 Oct 2019 13:08:23 +0800 > > > > > Zhenyu Wang <zhenyuw@linux.intel.com> wrote: > > > > > > > > > > > Hi, > > > > > > > > > > > > This is a refresh for previous send of this series. I got impression > that > > > > > > some SIOV drivers would still deploy their own create and config > > > method so > > > > > > stopped effort on this. But seems this would still be useful for > some > > > other > > > > > > SIOV driver which may simply want capability to aggregate > resources. > > > So here's > > > > > > refreshed series. > > > > > > > > > > > > Current mdev device create interface depends on fixed mdev type, > > > which get uuid > > > > > > from user to create instance of mdev device. If user wants to use > > > customized > > > > > > number of resource for mdev device, then only can create new > mdev > > > type for that > > > > > > which may not be flexible. This requirement comes not only from > to > > > be able to > > > > > > allocate flexible resources for KVMGT, but also from Intel scalable > IO > > > > > > virtualization which would use vfio/mdev to be able to allocate > > > arbitrary > > > > > > resources on mdev instance. More info on [1] [2] [3]. > > > > > > > > > > > > To allow to create user defined resources for mdev, it trys to > extend > > > mdev > > > > > > create interface by adding new "aggregate=xxx" parameter > following > > > UUID, for > > > > > > target mdev type if aggregation is supported, it can create new > mdev > > > device > > > > > > which contains resources combined by number of instances, e.g > > > > > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > > attribute which > > > > > > can support this setting. If no "aggregation" attribute found for > mdev > > > type, > > > > > > previous behavior is still kept for one instance allocation. And new > > > sysfs > > > > > > attribute "aggregated_instances" is created for each mdev device > to > > > show allocated number. > > > > > > > > > > Given discussions we've had recently around libvirt interacting with > > > > > mdev, I think that libvirt would rather have an abstract interface via > > > > > mdevctl[1]. Therefore can you evaluate how mdevctl would support > > > this > > > > > creation extension? It seems like it would fit within the existing > > > > > mdev and mdevctl framework if aggregation were simply a sysfs > > > attribute > > > > > for the device. For example, the mdevctl steps might look like this: > > > > > > > > > > mdevctl define -u UUID -p PARENT -t TYPE > > > > > mdevctl modify -u UUID --addattr=mdev/aggregation --value=2 > > > > > mdevctl start -u UUID > > > > Hi, Alex, can you elaborate why a sysfs attribute is more friendly > > to mdevctl? what is the complexity if having mdevctl to pass > > additional parameter at creation time as this series originally > > proposed? Just want to clearly understand the limitation of the > > parameter way. :-) > > We could also flip this question around, vfio-ap already uses sysfs to > finish composing a device after it's created, therefore why shouldn't > aggregation use this existing mechanism. Extending the creation > interface is a more fundamental change than simply standardizing an > optional sysfs namespace entry. > > > > > > > > > > > When mdevctl starts the mdev, it will first create it using the > > > > > existing mechanism, then apply aggregation attribute, which can > > > consume > > > > > the necessary additional instances from the parent device, or return > an > > > > > error, which would unwind and return a failure code to the caller > > > > > (libvirt). I think the vendor driver would then have freedom to > decide > > > > > when the attribute could be modified, for instance it would be > entirely > > > > > reasonable to return -EBUSY if the user attempts to modify the > > > > > attribute while the mdev device is in-use. Effectively aggregation > > > > > simply becomes a standardized attribute with common meaning. > > > Thoughts? > > > > > [cc libvirt folks for their impression] Thanks, > > > > > > > > I think one problem is that before mdevctl start to create mdev you > > > > don't know what vendor attributes are, as we apply mdev attributes > > > > after create. You may need some lookup depending on parent.. I think > > > > making aggregation like other vendor attribute for mdev might be the > > > > simplest way, but do we want to define its behavior in formal? e.g > > > > like previous discussed it should show maxium instances for > aggregation, > > > etc. > > > > > > Yes, we'd still want to standardize how we enable and discover > > > aggregation since we expect multiple users. Even if libvirt were to > > > use mdevctl as it's mdev interface, higher level tools should have an > > > introspection mechanism available. Possibly the sysfs interfaces > > > proposed in this series remains largely the same, but I think perhaps > > > the implementation of them moves out to the vendor driver. In fact, > > > perhaps the only change to mdev core is to define the standard. For > > > example, the "aggregation" attribute on the type is potentially simply > > > a defined, optional, per type attribute, similar to "name" and > > > "description". For "aggregated_instances" we already have the > > > mdev_attr_groups of the mdev_parent_ops, we could define an > > > attribute_group with .name = "mdev" as a set of standardized > > > attributes, such that vendors could provide both their own vendor > > > specific attributes and per device attributes with a common meaning > and > > > semantic defined in the mdev ABI. > > > > such standardization sounds good. > > > > > > > > > The behavior change for driver is that previously aggregation is > > > > handled at create time, but for sysfs attr it should handle any > > > > resource allocation before it's really in-use. I think some SIOV > > > > driver which already requires some specific config should be ok, > > > > but not sure for other driver which might not be explored in this > before. > > > > Would that be a problem? Kevin? > > > > > > Right, I'm assuming the aggregation could be modified until the device > > > is actually opened, the driver can nak the aggregation request by > > > returning an errno to the attribute write. I'm trying to anticipate > > > whether this introduces new complications, for instances races with > > > contiguous allocations. I think these seem solvable within the vendor > > > drivers, but please note it if I'm wrong. Thanks, > > > > > > > So far I didn't see a problem with this way. Regarding to contiguous > > allocations, ideally it should be fine as long as aggregation paths are > > properly locked similar as creation paths when allocating resources. > > It will introduce some additional work in vendor driver but such > > overhead is worthy if it leads to cleaner uapi. > > > > There is one open though. In concept the aggregation feature can > > be used for both increasing and decreasing the resource when > > exposing as a sysfs attribute, any time when the device is not in-use. > > Increasing resource is possibly fine, but I'm not sure about decreasing > > resource. Is there any vendor driver which cannot afford resource > > decrease once it has ever been used (after deassignment), or require > > at least an explicit reset before decrease? If yes, how do we report > > such special requirement (only-once, multiple-times, multiple-times- > > before-1st-usage) to user space? > > It seems like a sloppy vendor driver that couldn't return a device to a > post-creation state, ie. drop and re-initialize the aggregation state. might be hardware limitation too... > Userspace would always need to handle an aggregation failure, there > might be multiple processes attempting to allocate resources > simultaneously or the user might simply be requesting more resources > than available. The vendor driver should make a reasonable attempt to > satisfy the user request or else an insufficient resource error may > appear at the application. vfio-mdev devices should always be reset > before and after usage. the two scenarios are different. One is to let userspace know whether aggregation is supported, and any limitation. The other is to use the feature under claimed limitations and then includes error handling logic in case resource contention. > > > It's sort of like what Cornelia commented about standardization > > of post-creation resource configuration. If it may end up to be > > a complex story (or at least take time to understand/standardize > > all kinds of requirements), does it still make sense to support > > creation-time parameter as a quick-path for this aggregation feature? :-) > > We're not going to do both, right? We likely lock ourselves into one > schema when we do it. Not only is the sysfs approach already in use in > vfio-ap, but it seems more flexible. Above you raise the issue of > dynamically resizing the aggregation between uses. We can't do that > with only a creation-time parameter. With a sysfs parameter the vendor yes, because creation-time parameter is one-off. > driver can nak changes, allow changes when idle, potentially even allow > changes while in use. Connie essentially brings up the question of how > we can introspect sysfs attribute, which is a big question. Perhaps we > can nibble off a piece of that question by starting with a namespace > per attribute. For instance, rather than doing: > > echo 2 > /sys/bus/mdev/devices/UUID/mdev/aggregation > > We could do: > > echo 2 > /sys/bus/mdev/devices/UUID/mdev/aggregation/value > > This allows us the whole mdev/aggregation/* namespace to describe other > attributes to expose aspects of the aggregation support. Thanks, > en, this sounds a better option. We can start with one attribute (value) and extend to cover any possible restriction in the future. One note to Zhenyu - with this approach at least you should prepare for both increasing and decreasing resource through 'value' in GVT-g driver. Thanks Kevin
+ Jiri + Netdev since you mentioned netdev queue. + Jason Wang and Michael as we had similar discussion in vdpa discussion thread. > From: Zhenyu Wang <zhenyuw@linux.intel.com> > Sent: Friday, November 8, 2019 2:19 AM > To: Parav Pandit <parav@mellanox.com> > My apologies to reply late. Something bad with my email client, due to which I found this patch under spam folder today. More comments below. > On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > > Hi, > > > > > -----Original Message----- > > > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On > > > Behalf Of Zhenyu Wang > > > Sent: Thursday, October 24, 2019 12:08 AM > > > To: kvm@vger.kernel.org > > > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > > kevin.tian@intel.com; cohuck@redhat.com > > > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > > > > > Hi, > > > > > > This is a refresh for previous send of this series. I got impression > > > that some SIOV drivers would still deploy their own create and > > > config method so stopped effort on this. But seems this would still > > > be useful for some other SIOV driver which may simply want > > > capability to aggregate resources. So here's refreshed series. > > > > > > Current mdev device create interface depends on fixed mdev type, > > > which get uuid from user to create instance of mdev device. If user > > > wants to use customized number of resource for mdev device, then > > > only can create new > > Can you please give an example of 'resource'? > > When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'. > > The resource is vendor device specific, in SIOV spec there's ADI (Assignable > Device Interface) definition which could be e.g queue for net device, context > for gpu, etc. I just named this interface as 'aggregate' > for aggregation purpose, it's not used in spec doc. > Some 'unknown/undefined' vendor specific resource just doesn't work. Orchestration tool doesn't know which resource and what/how to configure for which vendor. It has to be well defined. You can also find such discussion in recent lgpu DRM cgroup patches series v4. Exposing networking resource configuration in non-net namespace aware mdev sysfs at PCI device level is no-go. Adding per file NET_ADMIN or other checks is not the approach we follow in kernel. devlink has been a subsystem though under net, that has very rich interface for syscaller, device health, resource management and many more. Even though it is used by net driver today, its written for generic device management at bus/device level. Yuval has posted patches to manage PCI sub-devices [1] and updated version will be posted soon which addresses comments. For any device slice resource management of mdev, sub-function etc, we should be using single kernel interface as devlink [2], [3]. [1] https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuvalav@mellanox.com/ [2] http://man7.org/linux/man-pages/man8/devlink-dev.8.html [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html Most modern device configuration that I am aware of is usually done via well defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or via netlink commands (net, devlink, rdma and more) not via sysfs. > Thanks > > > > > > mdev type for that which may not be flexible. This requirement comes > > > not only from to be able to allocate flexible resources for KVMGT, > > > but also from Intel scalable IO virtualization which would use > > > vfio/mdev to be able to allocate arbitrary resources on mdev instance. > More info on [1] [2] [3]. > > > > > > To allow to create user defined resources for mdev, it trys to > > > extend mdev create interface by adding new "aggregate=xxx" parameter > > > following UUID, for target mdev type if aggregation is supported, it > > > can create new mdev device which contains resources combined by > > > number of instances, e.g > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > > attribute which can support this setting. If no "aggregation" > > > attribute found for mdev type, previous behavior is still kept for > > > one instance allocation. And new sysfs attribute > > > "aggregated_instances" is created for each mdev device to show allocated > number. > > > > > > References: > > > [1] > > > https://software.intel.com/en-us/download/intel-virtualization-techn > > > ology- for-directed-io-architecture-specification > > > [2] > > > https://software.intel.com/en-us/download/intel-scalable-io-virtuali > > > zation- > > > technical-specification > > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > > > Zhenyu Wang (6): > > > vfio/mdev: Add new "aggregate" parameter for mdev create > > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > > device > > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > > vfio/mdev aggregation support > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > > aggregation support > > > drm/i915/gvt: Add new type with aggregation support > > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > > drivers/vfio/mdev/mdev_private.h | 6 +- > > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > > include/linux/mdev.h | 19 +++++ > > > 10 files changed, 294 insertions(+), 17 deletions(-) > > > > > > -- > > > 2.24.0.rc0 > > > > -- > Open Source Technology Center, Intel ltd. > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
On 2019.12.04 17:36:12 +0000, Parav Pandit wrote: > + Jiri + Netdev since you mentioned netdev queue. > > + Jason Wang and Michael as we had similar discussion in vdpa discussion thread. > > > From: Zhenyu Wang <zhenyuw@linux.intel.com> > > Sent: Friday, November 8, 2019 2:19 AM > > To: Parav Pandit <parav@mellanox.com> > > > > My apologies to reply late. > Something bad with my email client, due to which I found this patch under spam folder today. > More comments below. > > > On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > > > Hi, > > > > > > > -----Original Message----- > > > > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On > > > > Behalf Of Zhenyu Wang > > > > Sent: Thursday, October 24, 2019 12:08 AM > > > > To: kvm@vger.kernel.org > > > > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > > > kevin.tian@intel.com; cohuck@redhat.com > > > > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > > > > > > > Hi, > > > > > > > > This is a refresh for previous send of this series. I got impression > > > > that some SIOV drivers would still deploy their own create and > > > > config method so stopped effort on this. But seems this would still > > > > be useful for some other SIOV driver which may simply want > > > > capability to aggregate resources. So here's refreshed series. > > > > > > > > Current mdev device create interface depends on fixed mdev type, > > > > which get uuid from user to create instance of mdev device. If user > > > > wants to use customized number of resource for mdev device, then > > > > only can create new > > > Can you please give an example of 'resource'? > > > When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'. > > > > The resource is vendor device specific, in SIOV spec there's ADI (Assignable > > Device Interface) definition which could be e.g queue for net device, context > > for gpu, etc. I just named this interface as 'aggregate' > > for aggregation purpose, it's not used in spec doc. > > > > Some 'unknown/undefined' vendor specific resource just doesn't work. > Orchestration tool doesn't know which resource and what/how to configure for which vendor. > It has to be well defined. > > You can also find such discussion in recent lgpu DRM cgroup patches series v4. > > Exposing networking resource configuration in non-net namespace aware mdev sysfs at PCI device level is no-go. > Adding per file NET_ADMIN or other checks is not the approach we follow in kernel. > > devlink has been a subsystem though under net, that has very rich interface for syscaller, device health, resource management and many more. > Even though it is used by net driver today, its written for generic device management at bus/device level. > > Yuval has posted patches to manage PCI sub-devices [1] and updated version will be posted soon which addresses comments. > > For any device slice resource management of mdev, sub-function etc, we should be using single kernel interface as devlink [2], [3]. > > [1] https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuvalav@mellanox.com/ > [2] http://man7.org/linux/man-pages/man8/devlink-dev.8.html > [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > > Most modern device configuration that I am aware of is usually done via well defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or via netlink commands (net, devlink, rdma and more) not via sysfs. > Current vfio/mdev configuration is via documented sysfs ABI instead of other ways. So this adhere to that way to introduce more configurable method on mdev device for standard, it's optional and not actually vendor specific e.g vfio-ap. I'm not sure how many devices support devlink now, or if really make sense to utilize devlink for other devices except net, or if really make sense to take mdev resource configuration from there... > > > > > > > > > mdev type for that which may not be flexible. This requirement comes > > > > not only from to be able to allocate flexible resources for KVMGT, > > > > but also from Intel scalable IO virtualization which would use > > > > vfio/mdev to be able to allocate arbitrary resources on mdev instance. > > More info on [1] [2] [3]. > > > > > > > > To allow to create user defined resources for mdev, it trys to > > > > extend mdev create interface by adding new "aggregate=xxx" parameter > > > > following UUID, for target mdev type if aggregation is supported, it > > > > can create new mdev device which contains resources combined by > > > > number of instances, e.g > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > > > attribute which can support this setting. If no "aggregation" > > > > attribute found for mdev type, previous behavior is still kept for > > > > one instance allocation. And new sysfs attribute > > > > "aggregated_instances" is created for each mdev device to show allocated > > number. > > > > > > > > References: > > > > [1] > > > > https://software.intel.com/en-us/download/intel-virtualization-techn > > > > ology- for-directed-io-architecture-specification > > > > [2] > > > > https://software.intel.com/en-us/download/intel-scalable-io-virtuali > > > > zation- > > > > technical-specification > > > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > > > > > Zhenyu Wang (6): > > > > vfio/mdev: Add new "aggregate" parameter for mdev create > > > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > > > device > > > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > > > vfio/mdev aggregation support > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > > > aggregation support > > > > drm/i915/gvt: Add new type with aggregation support > > > > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > > > drivers/vfio/mdev/mdev_private.h | 6 +- > > > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > > > include/linux/mdev.h | 19 +++++ > > > > 10 files changed, 294 insertions(+), 17 deletions(-) > > > > > > > > -- > > > > 2.24.0.rc0 > > > > > > > -- > > Open Source Technology Center, Intel ltd. > > > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
On 2019/12/5 下午2:06, Zhenyu Wang wrote: > On 2019.12.04 17:36:12 +0000, Parav Pandit wrote: >> + Jiri + Netdev since you mentioned netdev queue. >> >> + Jason Wang and Michael as we had similar discussion in vdpa discussion thread. >> >>> From: Zhenyu Wang <zhenyuw@linux.intel.com> >>> Sent: Friday, November 8, 2019 2:19 AM >>> To: Parav Pandit <parav@mellanox.com> >>> >> My apologies to reply late. >> Something bad with my email client, due to which I found this patch under spam folder today. >> More comments below. >> >>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: >>>> Hi, >>>> >>>>> -----Original Message----- >>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On >>>>> Behalf Of Zhenyu Wang >>>>> Sent: Thursday, October 24, 2019 12:08 AM >>>>> To: kvm@vger.kernel.org >>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; >>>>> kevin.tian@intel.com; cohuck@redhat.com >>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling >>>>> >>>>> Hi, >>>>> >>>>> This is a refresh for previous send of this series. I got impression >>>>> that some SIOV drivers would still deploy their own create and >>>>> config method so stopped effort on this. But seems this would still >>>>> be useful for some other SIOV driver which may simply want >>>>> capability to aggregate resources. So here's refreshed series. >>>>> >>>>> Current mdev device create interface depends on fixed mdev type, >>>>> which get uuid from user to create instance of mdev device. If user >>>>> wants to use customized number of resource for mdev device, then >>>>> only can create new >>>> Can you please give an example of 'resource'? >>>> When I grep [1], [2] and [3], I couldn't find anything related to ' aggregate'. >>> The resource is vendor device specific, in SIOV spec there's ADI (Assignable >>> Device Interface) definition which could be e.g queue for net device, context >>> for gpu, etc. I just named this interface as 'aggregate' >>> for aggregation purpose, it's not used in spec doc. >>> >> Some 'unknown/undefined' vendor specific resource just doesn't work. >> Orchestration tool doesn't know which resource and what/how to configure for which vendor. >> It has to be well defined. >> >> You can also find such discussion in recent lgpu DRM cgroup patches series v4. >> >> Exposing networking resource configuration in non-net namespace aware mdev sysfs at PCI device level is no-go. >> Adding per file NET_ADMIN or other checks is not the approach we follow in kernel. >> >> devlink has been a subsystem though under net, that has very rich interface for syscaller, device health, resource management and many more. >> Even though it is used by net driver today, its written for generic device management at bus/device level. >> >> Yuval has posted patches to manage PCI sub-devices [1] and updated version will be posted soon which addresses comments. >> >> For any device slice resource management of mdev, sub-function etc, we should be using single kernel interface as devlink [2], [3]. >> >> [1] https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuvalav@mellanox.com/ >> [2] http://man7.org/linux/man-pages/man8/devlink-dev.8.html >> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html >> >> Most modern device configuration that I am aware of is usually done via well defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or via netlink commands (net, devlink, rdma and more) not via sysfs. >> > Current vfio/mdev configuration is via documented sysfs ABI instead of > other ways. So this adhere to that way to introduce more configurable > method on mdev device for standard, it's optional and not actually > vendor specific e.g vfio-ap. > > I'm not sure how many devices support devlink now, or if really make > sense to utilize devlink for other devices except net, or if really make > sense to take mdev resource configuration from there... It may make sense to allow other types of API to manage mdev other than sysfs. But I'm not sure whether or not it will be a challenge for orchestration. Thanks >>>>> mdev type for that which may not be flexible. This requirement comes >>>>> not only from to be able to allocate flexible resources for KVMGT, >>>>> but also from Intel scalable IO virtualization which would use >>>>> vfio/mdev to be able to allocate arbitrary resources on mdev instance. >>> More info on [1] [2] [3]. >>>>> To allow to create user defined resources for mdev, it trys to >>>>> extend mdev create interface by adding new "aggregate=xxx" parameter >>>>> following UUID, for target mdev type if aggregation is supported, it >>>>> can create new mdev device which contains resources combined by >>>>> number of instances, e.g >>>>> >>>>> echo "<uuid>,aggregate=10" > create >>>>> >>>>> VM manager e.g libvirt can check mdev type with "aggregation" >>>>> attribute which can support this setting. If no "aggregation" >>>>> attribute found for mdev type, previous behavior is still kept for >>>>> one instance allocation. And new sysfs attribute >>>>> "aggregated_instances" is created for each mdev device to show allocated >>> number. >>>>> References: >>>>> [1] >>>>> https://software.intel.com/en-us/download/intel-virtualization-techn >>>>> ology- for-directed-io-architecture-specification >>>>> [2] >>>>> https://software.intel.com/en-us/download/intel-scalable-io-virtuali >>>>> zation- >>>>> technical-specification >>>>> [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf >>>>> >>>>> Zhenyu Wang (6): >>>>> vfio/mdev: Add new "aggregate" parameter for mdev create >>>>> vfio/mdev: Add "aggregation" attribute for supported mdev type >>>>> vfio/mdev: Add "aggregated_instances" attribute for supported mdev >>>>> device >>>>> Documentation/driver-api/vfio-mediated-device.rst: Update for >>>>> vfio/mdev aggregation support >>>>> Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev >>>>> aggregation support >>>>> drm/i915/gvt: Add new type with aggregation support >>>>> >>>>> Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ >>>>> .../driver-api/vfio-mediated-device.rst | 23 ++++++ >>>>> drivers/gpu/drm/i915/gvt/gvt.c | 4 +- >>>>> drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- >>>>> drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- >>>>> drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- >>>>> drivers/vfio/mdev/mdev_core.c | 36 ++++++++- >>>>> drivers/vfio/mdev/mdev_private.h | 6 +- >>>>> drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- >>>>> include/linux/mdev.h | 19 +++++ >>>>> 10 files changed, 294 insertions(+), 17 deletions(-) >>>>> >>>>> -- >>>>> 2.24.0.rc0 >>> -- >>> Open Source Technology Center, Intel ltd. >>> >>> $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
> From: Zhenyu Wang <zhenyuw@linux.intel.com> > Sent: Thursday, December 5, 2019 12:06 AM > To: Parav Pandit <parav@mellanox.com> > > On 2019.12.04 17:36:12 +0000, Parav Pandit wrote: > > + Jiri + Netdev since you mentioned netdev queue. > > > > + Jason Wang and Michael as we had similar discussion in vdpa discussion > thread. > > > > > From: Zhenyu Wang <zhenyuw@linux.intel.com> > > > Sent: Friday, November 8, 2019 2:19 AM > > > To: Parav Pandit <parav@mellanox.com> > > > > > > > My apologies to reply late. > > Something bad with my email client, due to which I found this patch under > spam folder today. > > More comments below. > > > > > On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > > > > Hi, > > > > > > > > > -----Original Message----- > > > > > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On > > > > > Behalf Of Zhenyu Wang > > > > > Sent: Thursday, October 24, 2019 12:08 AM > > > > > To: kvm@vger.kernel.org > > > > > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > > > > kevin.tian@intel.com; cohuck@redhat.com > > > > > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > > > > > > > > > Hi, > > > > > > > > > > This is a refresh for previous send of this series. I got > > > > > impression that some SIOV drivers would still deploy their own > > > > > create and config method so stopped effort on this. But seems > > > > > this would still be useful for some other SIOV driver which may > > > > > simply want capability to aggregate resources. So here's refreshed > series. > > > > > > > > > > Current mdev device create interface depends on fixed mdev type, > > > > > which get uuid from user to create instance of mdev device. If > > > > > user wants to use customized number of resource for mdev device, > > > > > then only can create new > > > > Can you please give an example of 'resource'? > > > > When I grep [1], [2] and [3], I couldn't find anything related to ' > aggregate'. > > > > > > The resource is vendor device specific, in SIOV spec there's ADI > > > (Assignable Device Interface) definition which could be e.g queue > > > for net device, context for gpu, etc. I just named this interface as > 'aggregate' > > > for aggregation purpose, it's not used in spec doc. > > > > > > > Some 'unknown/undefined' vendor specific resource just doesn't work. > > Orchestration tool doesn't know which resource and what/how to configure > for which vendor. > > It has to be well defined. > > > > You can also find such discussion in recent lgpu DRM cgroup patches series > v4. > > > > Exposing networking resource configuration in non-net namespace aware > mdev sysfs at PCI device level is no-go. > > Adding per file NET_ADMIN or other checks is not the approach we follow in > kernel. > > > > devlink has been a subsystem though under net, that has very rich interface > for syscaller, device health, resource management and many more. > > Even though it is used by net driver today, its written for generic device > management at bus/device level. > > > > Yuval has posted patches to manage PCI sub-devices [1] and updated version > will be posted soon which addresses comments. > > > > For any device slice resource management of mdev, sub-function etc, we > should be using single kernel interface as devlink [2], [3]. > > > > [1] > > https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuval > > av@mellanox.com/ [2] > > http://man7.org/linux/man-pages/man8/devlink-dev.8.html > > [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > > > > Most modern device configuration that I am aware of is usually done via well > defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or > via netlink commands (net, devlink, rdma and more) not via sysfs. > > > > Current vfio/mdev configuration is via documented sysfs ABI instead of other > ways. So this adhere to that way to introduce more configurable method on > mdev device for standard, it's optional and not actually vendor specific e.g vfio- > ap. > Some unknown/undefined resource as 'aggregate' is just not an ABI. It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or something similar appropriate to that mdev device class. If user wants to set a parameter for a mdev regardless of vendor, they must have single way to do so. > I'm not sure how many devices support devlink now, or if really make sense to > utilize devlink for other devices except net, or if really make sense to take > mdev resource configuration from there... > This is about adding new knobs not the existing one. It has to be well defined. 'aggregate' is not the word that describes it. If this is something very device specific, it should be prefixed with 'misc_' something.. or it should be misc_X ioctl(). Miscellaneous not so well defined class of devices are usually registered using misc_register(). Similarly attributes has to be well defined, otherwise, it should fall under misc category specially when you are pointing to 3 well defined specifications. > > > > > > > > > > > > mdev type for that which may not be flexible. This requirement > > > > > comes not only from to be able to allocate flexible resources > > > > > for KVMGT, but also from Intel scalable IO virtualization which > > > > > would use vfio/mdev to be able to allocate arbitrary resources on mdev > instance. > > > More info on [1] [2] [3]. > > > > > > > > > > To allow to create user defined resources for mdev, it trys to > > > > > extend mdev create interface by adding new "aggregate=xxx" > > > > > parameter following UUID, for target mdev type if aggregation is > > > > > supported, it can create new mdev device which contains > > > > > resources combined by number of instances, e.g > > > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > > > > attribute which can support this setting. If no "aggregation" > > > > > attribute found for mdev type, previous behavior is still kept > > > > > for one instance allocation. And new sysfs attribute > > > > > "aggregated_instances" is created for each mdev device to show > > > > > allocated > > > number. > > > > > > > > > > References: > > > > > [1] > > > > > https://software.intel.com/en-us/download/intel-virtualization-t > > > > > echn > > > > > ology- for-directed-io-architecture-specification > > > > > [2] > > > > > https://software.intel.com/en-us/download/intel-scalable-io-virt > > > > > uali > > > > > zation- > > > > > technical-specification > > > > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > > > > > > > Zhenyu Wang (6): > > > > > vfio/mdev: Add new "aggregate" parameter for mdev create > > > > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > > > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > > > > device > > > > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > > > > vfio/mdev aggregation support > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > > > > aggregation support > > > > > drm/i915/gvt: Add new type with aggregation support > > > > > > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > > > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > > > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > > > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > > > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > > > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > > > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > > > > drivers/vfio/mdev/mdev_private.h | 6 +- > > > > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > > > > include/linux/mdev.h | 19 +++++ > > > > > 10 files changed, 294 insertions(+), 17 deletions(-) > > > > > > > > > > -- > > > > > 2.24.0.rc0 > > > > > > > > > > -- > > > Open Source Technology Center, Intel ltd. > > > > > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827 > > -- > Open Source Technology Center, Intel ltd. > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
Hi Jason, > From: Jason Wang <jasowang@redhat.com> > Sent: Thursday, December 5, 2019 12:41 AM > > > On 2019/12/5 下午2:06, Zhenyu Wang wrote: > > On 2019.12.04 17:36:12 +0000, Parav Pandit wrote: > >> + Jiri + Netdev since you mentioned netdev queue. > >> > >> + Jason Wang and Michael as we had similar discussion in vdpa discussion > thread. > >> > >>> From: Zhenyu Wang <zhenyuw@linux.intel.com> > >>> Sent: Friday, November 8, 2019 2:19 AM > >>> To: Parav Pandit <parav@mellanox.com> > >>> > >> My apologies to reply late. > >> Something bad with my email client, due to which I found this patch under > spam folder today. > >> More comments below. > >> > >>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > >>>> Hi, > >>>> > >>>>> -----Original Message----- > >>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On > >>>>> Behalf Of Zhenyu Wang > >>>>> Sent: Thursday, October 24, 2019 12:08 AM > >>>>> To: kvm@vger.kernel.org > >>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > >>>>> kevin.tian@intel.com; cohuck@redhat.com > >>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > >>>>> > >>>>> Hi, > >>>>> > >>>>> This is a refresh for previous send of this series. I got > >>>>> impression that some SIOV drivers would still deploy their own > >>>>> create and config method so stopped effort on this. But seems this > >>>>> would still be useful for some other SIOV driver which may simply > >>>>> want capability to aggregate resources. So here's refreshed series. > >>>>> > >>>>> Current mdev device create interface depends on fixed mdev type, > >>>>> which get uuid from user to create instance of mdev device. If > >>>>> user wants to use customized number of resource for mdev device, > >>>>> then only can create new > >>>> Can you please give an example of 'resource'? > >>>> When I grep [1], [2] and [3], I couldn't find anything related to ' > aggregate'. > >>> The resource is vendor device specific, in SIOV spec there's ADI > >>> (Assignable Device Interface) definition which could be e.g queue > >>> for net device, context for gpu, etc. I just named this interface as > 'aggregate' > >>> for aggregation purpose, it's not used in spec doc. > >>> > >> Some 'unknown/undefined' vendor specific resource just doesn't work. > >> Orchestration tool doesn't know which resource and what/how to configure > for which vendor. > >> It has to be well defined. > >> > >> You can also find such discussion in recent lgpu DRM cgroup patches series > v4. > >> > >> Exposing networking resource configuration in non-net namespace aware > mdev sysfs at PCI device level is no-go. > >> Adding per file NET_ADMIN or other checks is not the approach we follow in > kernel. > >> > >> devlink has been a subsystem though under net, that has very rich interface > for syscaller, device health, resource management and many more. > >> Even though it is used by net driver today, its written for generic device > management at bus/device level. > >> > >> Yuval has posted patches to manage PCI sub-devices [1] and updated version > will be posted soon which addresses comments. > >> > >> For any device slice resource management of mdev, sub-function etc, we > should be using single kernel interface as devlink [2], [3]. > >> > >> [1] > >> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuva > >> lav@mellanox.com/ [2] > >> http://man7.org/linux/man-pages/man8/devlink-dev.8.html > >> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > >> > >> Most modern device configuration that I am aware of is usually done via > well defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) > or via netlink commands (net, devlink, rdma and more) not via sysfs. > >> > > Current vfio/mdev configuration is via documented sysfs ABI instead of > > other ways. So this adhere to that way to introduce more configurable > > method on mdev device for standard, it's optional and not actually > > vendor specific e.g vfio-ap. > > > > I'm not sure how many devices support devlink now, or if really make > > sense to utilize devlink for other devices except net, or if really > > make sense to take mdev resource configuration from there... > > > It may make sense to allow other types of API to manage mdev other than > sysfs. But I'm not sure whether or not it will be a challenge for orchestration. > There are two parts. 1. How you specify resource config (sysfs/netlink/devlink/ioctl etc) 2. definition of the resource itself. It has to be well defined. Or it should be categorized as miscellaneous. It cannot be some undefined/vague name as 'aggregate'. > Thanks > > > >>>>> mdev type for that which may not be flexible. This requirement > >>>>> comes not only from to be able to allocate flexible resources for > >>>>> KVMGT, but also from Intel scalable IO virtualization which would > >>>>> use vfio/mdev to be able to allocate arbitrary resources on mdev > instance. > >>> More info on [1] [2] [3]. > >>>>> To allow to create user defined resources for mdev, it trys to > >>>>> extend mdev create interface by adding new "aggregate=xxx" > >>>>> parameter following UUID, for target mdev type if aggregation is > >>>>> supported, it can create new mdev device which contains resources > >>>>> combined by number of instances, e.g > >>>>> > >>>>> echo "<uuid>,aggregate=10" > create > >>>>> > >>>>> VM manager e.g libvirt can check mdev type with "aggregation" > >>>>> attribute which can support this setting. If no "aggregation" > >>>>> attribute found for mdev type, previous behavior is still kept for > >>>>> one instance allocation. And new sysfs attribute > >>>>> "aggregated_instances" is created for each mdev device to show > >>>>> allocated > >>> number. > >>>>> References: > >>>>> [1] > >>>>> https://software.intel.com/en-us/download/intel-virtualization-tec > >>>>> hn > >>>>> ology- for-directed-io-architecture-specification > >>>>> [2] > >>>>> https://software.intel.com/en-us/download/intel-scalable-io-virtua > >>>>> li > >>>>> zation- > >>>>> technical-specification > >>>>> [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > >>>>> > >>>>> Zhenyu Wang (6): > >>>>> vfio/mdev: Add new "aggregate" parameter for mdev create > >>>>> vfio/mdev: Add "aggregation" attribute for supported mdev type > >>>>> vfio/mdev: Add "aggregated_instances" attribute for supported mdev > >>>>> device > >>>>> Documentation/driver-api/vfio-mediated-device.rst: Update for > >>>>> vfio/mdev aggregation support > >>>>> Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > >>>>> aggregation support > >>>>> drm/i915/gvt: Add new type with aggregation support > >>>>> > >>>>> Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > >>>>> .../driver-api/vfio-mediated-device.rst | 23 ++++++ > >>>>> drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > >>>>> drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > >>>>> drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > >>>>> drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > >>>>> drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > >>>>> drivers/vfio/mdev/mdev_private.h | 6 +- > >>>>> drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > >>>>> include/linux/mdev.h | 19 +++++ > >>>>> 10 files changed, 294 insertions(+), 17 deletions(-) > >>>>> > >>>>> -- > >>>>> 2.24.0.rc0 > >>> -- > >>> Open Source Technology Center, Intel ltd. > >>> > >>> $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: > > > > > > > On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > > > > > Hi, > > > > > > > > > > > -----Original Message----- > > > > > > From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On > > > > > > Behalf Of Zhenyu Wang > > > > > > Sent: Thursday, October 24, 2019 12:08 AM > > > > > > To: kvm@vger.kernel.org > > > > > > Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > > > > > kevin.tian@intel.com; cohuck@redhat.com > > > > > > Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > > > > > > > > > > > Hi, > > > > > > > > > > > > This is a refresh for previous send of this series. I got > > > > > > impression that some SIOV drivers would still deploy their own > > > > > > create and config method so stopped effort on this. But seems > > > > > > this would still be useful for some other SIOV driver which may > > > > > > simply want capability to aggregate resources. So here's refreshed > > series. > > > > > > > > > > > > Current mdev device create interface depends on fixed mdev type, > > > > > > which get uuid from user to create instance of mdev device. If > > > > > > user wants to use customized number of resource for mdev device, > > > > > > then only can create new > > > > > Can you please give an example of 'resource'? > > > > > When I grep [1], [2] and [3], I couldn't find anything related to ' > > aggregate'. > > > > > > > > The resource is vendor device specific, in SIOV spec there's ADI > > > > (Assignable Device Interface) definition which could be e.g queue > > > > for net device, context for gpu, etc. I just named this interface as > > 'aggregate' > > > > for aggregation purpose, it's not used in spec doc. > > > > > > > > > > Some 'unknown/undefined' vendor specific resource just doesn't work. > > > Orchestration tool doesn't know which resource and what/how to configure > > for which vendor. > > > It has to be well defined. > > > > > > You can also find such discussion in recent lgpu DRM cgroup patches series > > v4. > > > > > > Exposing networking resource configuration in non-net namespace aware > > mdev sysfs at PCI device level is no-go. > > > Adding per file NET_ADMIN or other checks is not the approach we follow in > > kernel. > > > > > > devlink has been a subsystem though under net, that has very rich interface > > for syscaller, device health, resource management and many more. > > > Even though it is used by net driver today, its written for generic device > > management at bus/device level. > > > > > > Yuval has posted patches to manage PCI sub-devices [1] and updated version > > will be posted soon which addresses comments. > > > > > > For any device slice resource management of mdev, sub-function etc, we > > should be using single kernel interface as devlink [2], [3]. > > > > > > [1] > > > https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuval > > > av@mellanox.com/ [2] > > > http://man7.org/linux/man-pages/man8/devlink-dev.8.html > > > [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > > > > > > Most modern device configuration that I am aware of is usually done via well > > defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or > > via netlink commands (net, devlink, rdma and more) not via sysfs. > > > > > > > Current vfio/mdev configuration is via documented sysfs ABI instead of other > > ways. So this adhere to that way to introduce more configurable method on > > mdev device for standard, it's optional and not actually vendor specific e.g vfio- > > ap. > > > Some unknown/undefined resource as 'aggregate' is just not an ABI. > It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or something similar appropriate to that mdev device class. > If user wants to set a parameter for a mdev regardless of vendor, they must have single way to do so. The idea is not specific for some device class, but for each mdev type's resource, and be optional for each vendor. If more device class specific way is preferred, then we might have very different ways for different vendors. Better to avoid that, so here means to aggregate number of mdev type's resources for target instance, instead of defining kinds of mdev types for those number of resources. > > > I'm not sure how many devices support devlink now, or if really make sense to > > utilize devlink for other devices except net, or if really make sense to take > > mdev resource configuration from there... > > > This is about adding new knobs not the existing one. > It has to be well defined. 'aggregate' is not the word that describes it. > If this is something very device specific, it should be prefixed with 'misc_' something.. or it should be misc_X ioctl(). > Miscellaneous not so well defined class of devices are usually registered using misc_register(). > Similarly attributes has to be well defined, otherwise, it should fall under misc category specially when you are pointing to 3 well defined specifications. > Any suggestion for naming it? > > > > > > > > > > > > > > > mdev type for that which may not be flexible. This requirement > > > > > > comes not only from to be able to allocate flexible resources > > > > > > for KVMGT, but also from Intel scalable IO virtualization which > > > > > > would use vfio/mdev to be able to allocate arbitrary resources on mdev > > instance. > > > > More info on [1] [2] [3]. > > > > > > > > > > > > To allow to create user defined resources for mdev, it trys to > > > > > > extend mdev create interface by adding new "aggregate=xxx" > > > > > > parameter following UUID, for target mdev type if aggregation is > > > > > > supported, it can create new mdev device which contains > > > > > > resources combined by number of instances, e.g > > > > > > > > > > > > echo "<uuid>,aggregate=10" > create > > > > > > > > > > > > VM manager e.g libvirt can check mdev type with "aggregation" > > > > > > attribute which can support this setting. If no "aggregation" > > > > > > attribute found for mdev type, previous behavior is still kept > > > > > > for one instance allocation. And new sysfs attribute > > > > > > "aggregated_instances" is created for each mdev device to show > > > > > > allocated > > > > number. > > > > > > > > > > > > References: > > > > > > [1] > > > > > > https://software.intel.com/en-us/download/intel-virtualization-t > > > > > > echn > > > > > > ology- for-directed-io-architecture-specification > > > > > > [2] > > > > > > https://software.intel.com/en-us/download/intel-scalable-io-virt > > > > > > uali > > > > > > zation- > > > > > > technical-specification > > > > > > [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf > > > > > > > > > > > > Zhenyu Wang (6): > > > > > > vfio/mdev: Add new "aggregate" parameter for mdev create > > > > > > vfio/mdev: Add "aggregation" attribute for supported mdev type > > > > > > vfio/mdev: Add "aggregated_instances" attribute for supported mdev > > > > > > device > > > > > > Documentation/driver-api/vfio-mediated-device.rst: Update for > > > > > > vfio/mdev aggregation support > > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev > > > > > > aggregation support > > > > > > drm/i915/gvt: Add new type with aggregation support > > > > > > > > > > > > Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ > > > > > > .../driver-api/vfio-mediated-device.rst | 23 ++++++ > > > > > > drivers/gpu/drm/i915/gvt/gvt.c | 4 +- > > > > > > drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- > > > > > > drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- > > > > > > drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- > > > > > > drivers/vfio/mdev/mdev_core.c | 36 ++++++++- > > > > > > drivers/vfio/mdev/mdev_private.h | 6 +- > > > > > > drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- > > > > > > include/linux/mdev.h | 19 +++++ > > > > > > 10 files changed, 294 insertions(+), 17 deletions(-) > > > > > > > > > > > > -- > > > > > > 2.24.0.rc0 > > > > > > > > > > > > > -- > > > > Open Source Technology Center, Intel ltd. > > > > > > > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827 > > > > -- > > Open Source Technology Center, Intel ltd. > > > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
On 12/6/2019 2:03 AM, Zhenyu Wang wrote: > On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: >>>> >>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: >>>>>> Hi, >>>>>> >>>>>>> -----Original Message----- >>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On >>>>>>> Behalf Of Zhenyu Wang >>>>>>> Sent: Thursday, October 24, 2019 12:08 AM >>>>>>> To: kvm@vger.kernel.org >>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; >>>>>>> kevin.tian@intel.com; cohuck@redhat.com >>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> This is a refresh for previous send of this series. I got >>>>>>> impression that some SIOV drivers would still deploy their own >>>>>>> create and config method so stopped effort on this. But seems >>>>>>> this would still be useful for some other SIOV driver which may >>>>>>> simply want capability to aggregate resources. So here's refreshed >>> series. >>>>>>> >>>>>>> Current mdev device create interface depends on fixed mdev type, >>>>>>> which get uuid from user to create instance of mdev device. If >>>>>>> user wants to use customized number of resource for mdev device, >>>>>>> then only can create new >>>>>> Can you please give an example of 'resource'? >>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' >>> aggregate'. >>>>> >>>>> The resource is vendor device specific, in SIOV spec there's ADI >>>>> (Assignable Device Interface) definition which could be e.g queue >>>>> for net device, context for gpu, etc. I just named this interface as >>> 'aggregate' >>>>> for aggregation purpose, it's not used in spec doc. >>>>> >>>> >>>> Some 'unknown/undefined' vendor specific resource just doesn't work. >>>> Orchestration tool doesn't know which resource and what/how to configure >>> for which vendor. >>>> It has to be well defined. >>>> >>>> You can also find such discussion in recent lgpu DRM cgroup patches series >>> v4. >>>> >>>> Exposing networking resource configuration in non-net namespace aware >>> mdev sysfs at PCI device level is no-go. >>>> Adding per file NET_ADMIN or other checks is not the approach we follow in >>> kernel. >>>> >>>> devlink has been a subsystem though under net, that has very rich interface >>> for syscaller, device health, resource management and many more. >>>> Even though it is used by net driver today, its written for generic device >>> management at bus/device level. >>>> >>>> Yuval has posted patches to manage PCI sub-devices [1] and updated version >>> will be posted soon which addresses comments. >>>> >>>> For any device slice resource management of mdev, sub-function etc, we >>> should be using single kernel interface as devlink [2], [3]. >>>> >>>> [1] >>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email-yuval >>>> av@mellanox.com/ [2] >>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html >>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html >>>> >>>> Most modern device configuration that I am aware of is usually done via well >>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and more) or >>> via netlink commands (net, devlink, rdma and more) not via sysfs. >>>> >>> >>> Current vfio/mdev configuration is via documented sysfs ABI instead of other >>> ways. So this adhere to that way to introduce more configurable method on >>> mdev device for standard, it's optional and not actually vendor specific e.g vfio- >>> ap. >>> >> Some unknown/undefined resource as 'aggregate' is just not an ABI. >> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or something similar appropriate to that mdev device class. >> If user wants to set a parameter for a mdev regardless of vendor, they must have single way to do so. > > The idea is not specific for some device class, but for each mdev > type's resource, and be optional for each vendor. If more device class > specific way is preferred, then we might have very different ways for > different vendors. Better to avoid that, so here means to aggregate > number of mdev type's resources for target instance, instead of defining > kinds of mdev types for those number of resources. > Parameter or attribute certainly can be optional. But the way to aggregate them should not be vendor specific. Look for some excellent existing examples across subsystems, for example how you create aggregated netdev or block device is not depend on vendor or underlying device type. >> >>> I'm not sure how many devices support devlink now, or if really make sense to >>> utilize devlink for other devices except net, or if really make sense to take >>> mdev resource configuration from there... >>> >> This is about adding new knobs not the existing one. >> It has to be well defined. 'aggregate' is not the word that describes it. >> If this is something very device specific, it should be prefixed with 'misc_' something.. or it should be misc_X ioctl(). >> Miscellaneous not so well defined class of devices are usually registered using misc_register(). >> Similarly attributes has to be well defined, otherwise, it should fall under misc category specially when you are pointing to 3 well defined specifications. >> > > Any suggestion for naming it? If parameter is miscellaneous, please prefix it with misc in mdev ioctl() or in sysfs. If parameter/attribute is max_netdev_txqs for netdev, name as that, If its max_dedicated_wqs of some dsa device, please name is that way.
> From: Parav Pandit <parav@mellanox.com> > Sent: Saturday, December 7, 2019 1:34 AM > > On 12/6/2019 2:03 AM, Zhenyu Wang wrote: > > On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: > >>>> > >>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > >>>>>> Hi, > >>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> > On > >>>>>>> Behalf Of Zhenyu Wang > >>>>>>> Sent: Thursday, October 24, 2019 12:08 AM > >>>>>>> To: kvm@vger.kernel.org > >>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > >>>>>>> kevin.tian@intel.com; cohuck@redhat.com > >>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > >>>>>>> > >>>>>>> Hi, > >>>>>>> > >>>>>>> This is a refresh for previous send of this series. I got > >>>>>>> impression that some SIOV drivers would still deploy their own > >>>>>>> create and config method so stopped effort on this. But seems > >>>>>>> this would still be useful for some other SIOV driver which may > >>>>>>> simply want capability to aggregate resources. So here's refreshed > >>> series. > >>>>>>> > >>>>>>> Current mdev device create interface depends on fixed mdev type, > >>>>>>> which get uuid from user to create instance of mdev device. If > >>>>>>> user wants to use customized number of resource for mdev device, > >>>>>>> then only can create new > >>>>>> Can you please give an example of 'resource'? > >>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' > >>> aggregate'. > >>>>> > >>>>> The resource is vendor device specific, in SIOV spec there's ADI > >>>>> (Assignable Device Interface) definition which could be e.g queue > >>>>> for net device, context for gpu, etc. I just named this interface as > >>> 'aggregate' > >>>>> for aggregation purpose, it's not used in spec doc. > >>>>> > >>>> > >>>> Some 'unknown/undefined' vendor specific resource just doesn't work. > >>>> Orchestration tool doesn't know which resource and what/how to > configure > >>> for which vendor. > >>>> It has to be well defined. > >>>> > >>>> You can also find such discussion in recent lgpu DRM cgroup patches > series > >>> v4. > >>>> > >>>> Exposing networking resource configuration in non-net namespace > aware > >>> mdev sysfs at PCI device level is no-go. > >>>> Adding per file NET_ADMIN or other checks is not the approach we > follow in > >>> kernel. > >>>> > >>>> devlink has been a subsystem though under net, that has very rich > interface > >>> for syscaller, device health, resource management and many more. > >>>> Even though it is used by net driver today, its written for generic device > >>> management at bus/device level. > >>>> > >>>> Yuval has posted patches to manage PCI sub-devices [1] and updated > version > >>> will be posted soon which addresses comments. > >>>> > >>>> For any device slice resource management of mdev, sub-function etc, > we > >>> should be using single kernel interface as devlink [2], [3]. > >>>> > >>>> [1] > >>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email- > yuval > >>>> av@mellanox.com/ [2] > >>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html > >>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > >>>> > >>>> Most modern device configuration that I am aware of is usually done > via well > >>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and > more) or > >>> via netlink commands (net, devlink, rdma and more) not via sysfs. > >>>> > >>> > >>> Current vfio/mdev configuration is via documented sysfs ABI instead of > other > >>> ways. So this adhere to that way to introduce more configurable method > on > >>> mdev device for standard, it's optional and not actually vendor specific > e.g vfio- > >>> ap. > >>> > >> Some unknown/undefined resource as 'aggregate' is just not an ABI. > >> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or > something similar appropriate to that mdev device class. > >> If user wants to set a parameter for a mdev regardless of vendor, they > must have single way to do so. > > > > The idea is not specific for some device class, but for each mdev > > type's resource, and be optional for each vendor. If more device class > > specific way is preferred, then we might have very different ways for > > different vendors. Better to avoid that, so here means to aggregate > > number of mdev type's resources for target instance, instead of defining > > kinds of mdev types for those number of resources. > > > Parameter or attribute certainly can be optional. > But the way to aggregate them should not be vendor specific. > Look for some excellent existing examples across subsystems, for example > how you create aggregated netdev or block device is not depend on vendor > or underlying device type. I'd like to hear Alex's opinion on this. Today VFIO mdev supports two styles of "types" imo: fixed resource definition (most cases) and dynamic resource definition (vfio-ap). In fixed style, a type has fixed association to a set of vendor specific resources (resourceX=M, resourceY=N, ...). In dynamic case, the user is allowed to specify actual resource X/Y/... backing the mdev instance post its creation. In either case, the way to identify such association or configurable knobs is vendor specific, maybe contained in optional attributes (name and description) plus additional info in vendor documents. Then the user is assumed to clearly understand the implication of the resource allocation under a given type, when creating a new mdev under this type. If this assumption holds true, the aggregated attribute simply provides an extension in the same direction of fixed-style types but allowing for more flexible linearly-increasing resource allocation. e.g. when using aggregate=2, it means creating a instance with resourceX=2M, resourceY=2N, ... under the specified type. Along this direction I didn't see the need of well-defined vendor specific attributes here. When those are actually required, I suppose the dynamic style would better fit. Or if the vendor driver thinks implementing such aggregate feature will confuse its type definition, it's optional to not doing so anyway. Thanks Kevin
On Tue, 10 Dec 2019 03:33:23 +0000 "Tian, Kevin" <kevin.tian@intel.com> wrote: > > From: Parav Pandit <parav@mellanox.com> > > Sent: Saturday, December 7, 2019 1:34 AM > > > > On 12/6/2019 2:03 AM, Zhenyu Wang wrote: > > > On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: > > >>>> > > >>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > > >>>>>> Hi, > > >>>>>> > > >>>>>>> -----Original Message----- > > >>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> > > On > > >>>>>>> Behalf Of Zhenyu Wang > > >>>>>>> Sent: Thursday, October 24, 2019 12:08 AM > > >>>>>>> To: kvm@vger.kernel.org > > >>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > > >>>>>>> kevin.tian@intel.com; cohuck@redhat.com > > >>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > > >>>>>>> > > >>>>>>> Hi, > > >>>>>>> > > >>>>>>> This is a refresh for previous send of this series. I got > > >>>>>>> impression that some SIOV drivers would still deploy their own > > >>>>>>> create and config method so stopped effort on this. But seems > > >>>>>>> this would still be useful for some other SIOV driver which may > > >>>>>>> simply want capability to aggregate resources. So here's refreshed > > >>> series. > > >>>>>>> > > >>>>>>> Current mdev device create interface depends on fixed mdev type, > > >>>>>>> which get uuid from user to create instance of mdev device. If > > >>>>>>> user wants to use customized number of resource for mdev device, > > >>>>>>> then only can create new > > >>>>>> Can you please give an example of 'resource'? > > >>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' > > >>> aggregate'. > > >>>>> > > >>>>> The resource is vendor device specific, in SIOV spec there's ADI > > >>>>> (Assignable Device Interface) definition which could be e.g queue > > >>>>> for net device, context for gpu, etc. I just named this interface as > > >>> 'aggregate' > > >>>>> for aggregation purpose, it's not used in spec doc. > > >>>>> > > >>>> > > >>>> Some 'unknown/undefined' vendor specific resource just doesn't work. > > >>>> Orchestration tool doesn't know which resource and what/how to > > configure > > >>> for which vendor. > > >>>> It has to be well defined. > > >>>> > > >>>> You can also find such discussion in recent lgpu DRM cgroup patches > > series > > >>> v4. > > >>>> > > >>>> Exposing networking resource configuration in non-net namespace > > aware > > >>> mdev sysfs at PCI device level is no-go. > > >>>> Adding per file NET_ADMIN or other checks is not the approach we > > follow in > > >>> kernel. > > >>>> > > >>>> devlink has been a subsystem though under net, that has very rich > > interface > > >>> for syscaller, device health, resource management and many more. > > >>>> Even though it is used by net driver today, its written for generic device > > >>> management at bus/device level. > > >>>> > > >>>> Yuval has posted patches to manage PCI sub-devices [1] and updated > > version > > >>> will be posted soon which addresses comments. Always good to see tools that intend to manage arbitrary devices posted only to the netdev list :-\ > > >>>> > > >>>> For any device slice resource management of mdev, sub-function etc, > > we > > >>> should be using single kernel interface as devlink [2], [3]. This seems impractical, mdevs and SR-IOV are both enumerated, inspected, created, and removed in sysfs, where do we define what features are manipulated vis sysfs versus devlink? mdevs, by definition, are vendor defined "chunks" of a thing. We allow vendor drivers to define different types, representing different configurations of these chunks. Often these different types are incrementally bigger or smaller chunks of these things, but defining what bigger and smaller means generically across vendors is an impossible task. Orchestration tools already need to know vendor specific information in terms of what type of mdev device they want to create and make use of. The aggregation seems to simply augment that vendor information, ie. 'type' and 'scale' are separate rather than combined only behind just 'type'. > > >>>> > > >>>> [1] > > >>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email- > > yuval > > >>>> av@mellanox.com/ [2] > > >>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html > > >>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > > >>>> > > >>>> Most modern device configuration that I am aware of is usually done > > via well > > >>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and > > more) or > > >>> via netlink commands (net, devlink, rdma and more) not via sysfs. > > >>>> > > >>> > > >>> Current vfio/mdev configuration is via documented sysfs ABI instead of > > other > > >>> ways. So this adhere to that way to introduce more configurable method > > on > > >>> mdev device for standard, it's optional and not actually vendor specific > > e.g vfio- > > >>> ap. > > >>> > > >> Some unknown/undefined resource as 'aggregate' is just not an ABI. > > >> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or > > something similar appropriate to that mdev device class. > > >> If user wants to set a parameter for a mdev regardless of vendor, they > > must have single way to do so. Aggregation augments type, which is by definition vendor specific. > > > > > > The idea is not specific for some device class, but for each mdev > > > type's resource, and be optional for each vendor. If more device class > > > specific way is preferred, then we might have very different ways for > > > different vendors. Better to avoid that, so here means to aggregate > > > number of mdev type's resources for target instance, instead of defining > > > kinds of mdev types for those number of resources. > > > > > Parameter or attribute certainly can be optional. > > But the way to aggregate them should not be vendor specific. > > Look for some excellent existing examples across subsystems, for example > > how you create aggregated netdev or block device is not depend on vendor > > or underlying device type. > > I'd like to hear Alex's opinion on this. Today VFIO mdev supports two styles > of "types" imo: fixed resource definition (most cases) and dynamic resource > definition (vfio-ap). In fixed style, a type has fixed association to a set of > vendor specific resources (resourceX=M, resourceY=N, ...). In dynamic case, > the user is allowed to specify actual resource X/Y/... backing the mdev > instance post its creation. In either case, the way to identify such association > or configurable knobs is vendor specific, maybe contained in optional > attributes (name and description) plus additional info in vendor documents. > > Then the user is assumed to clearly understand the implication of the resource > allocation under a given type, when creating a new mdev under this type. > > If this assumption holds true, the aggregated attribute simply provides an > extension in the same direction of fixed-style types but allowing for more > flexible linearly-increasing resource allocation. e.g. when using aggregate=2, > it means creating a instance with resourceX=2M, resourceY=2N, ... under > the specified type. Along this direction I didn't see the need of well-defined > vendor specific attributes here. When those are actually required, I suppose > the dynamic style would better fit. Or if the vendor driver thinks implementing > such aggregate feature will confuse its type definition, it's optional to not > doing so anyway. Yep, though I don't think we can even define that aggregate=2 indicates that every resources is doubled, it's going to have vendor specific meaning. Maybe this is what Parav is rejecting, but I don't see an alternative. For example, an mdev vGPU might have high level resources like the number of execution units, graphics memory, display heads, maximum resolution, etc. Aggregation could affect one or all of these. Orchestration tools already need to know the vendor specific type of device they want to create, so it doesn't seem unreasonable that if they use aggregation that they choose a type that aggregates the resource(s) they need, but that aggregation is going to be specific to the type. Potentially as we think about adding "defined" sysfs attributes for devices we could start with $SYSFS_DEV_PATH/mdev/aggregation/type, where value written to type is a vendor specific aggregation of that mdev type. This allows us the option that we might someday agree on specific resources that might be aggregated in a common way (ex. ./aggregation/graphics_memory), but I'm somewhat doubtful those would ever be pursued. Thanks, Alex
On 12/10/2019 1:07 PM, Alex Williamson wrote: > On Tue, 10 Dec 2019 03:33:23 +0000 > "Tian, Kevin" <kevin.tian@intel.com> wrote: > >>> From: Parav Pandit <parav@mellanox.com> >>> Sent: Saturday, December 7, 2019 1:34 AM >>> >>> On 12/6/2019 2:03 AM, Zhenyu Wang wrote: >>>> On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: >>>>>>> >>>>>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>>> -----Original Message----- >>>>>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> >>> On >>>>>>>>>> Behalf Of Zhenyu Wang >>>>>>>>>> Sent: Thursday, October 24, 2019 12:08 AM >>>>>>>>>> To: kvm@vger.kernel.org >>>>>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; >>>>>>>>>> kevin.tian@intel.com; cohuck@redhat.com >>>>>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling >>>>>>>>>> >>>>>>>>>> Hi, >>>>>>>>>> >>>>>>>>>> This is a refresh for previous send of this series. I got >>>>>>>>>> impression that some SIOV drivers would still deploy their own >>>>>>>>>> create and config method so stopped effort on this. But seems >>>>>>>>>> this would still be useful for some other SIOV driver which may >>>>>>>>>> simply want capability to aggregate resources. So here's refreshed >>>>>> series. >>>>>>>>>> >>>>>>>>>> Current mdev device create interface depends on fixed mdev type, >>>>>>>>>> which get uuid from user to create instance of mdev device. If >>>>>>>>>> user wants to use customized number of resource for mdev device, >>>>>>>>>> then only can create new >>>>>>>>> Can you please give an example of 'resource'? >>>>>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' >>>>>> aggregate'. >>>>>>>> >>>>>>>> The resource is vendor device specific, in SIOV spec there's ADI >>>>>>>> (Assignable Device Interface) definition which could be e.g queue >>>>>>>> for net device, context for gpu, etc. I just named this interface as >>>>>> 'aggregate' >>>>>>>> for aggregation purpose, it's not used in spec doc. >>>>>>>> >>>>>>> >>>>>>> Some 'unknown/undefined' vendor specific resource just doesn't work. >>>>>>> Orchestration tool doesn't know which resource and what/how to >>> configure >>>>>> for which vendor. >>>>>>> It has to be well defined. >>>>>>> >>>>>>> You can also find such discussion in recent lgpu DRM cgroup patches >>> series >>>>>> v4. >>>>>>> >>>>>>> Exposing networking resource configuration in non-net namespace >>> aware >>>>>> mdev sysfs at PCI device level is no-go. >>>>>>> Adding per file NET_ADMIN or other checks is not the approach we >>> follow in >>>>>> kernel. >>>>>>> >>>>>>> devlink has been a subsystem though under net, that has very rich >>> interface >>>>>> for syscaller, device health, resource management and many more. >>>>>>> Even though it is used by net driver today, its written for generic device >>>>>> management at bus/device level. >>>>>>> >>>>>>> Yuval has posted patches to manage PCI sub-devices [1] and updated >>> version >>>>>> will be posted soon which addresses comments. > > Always good to see tools that intend to manage arbitrary devices posted > only to the netdev list :-\ > >>>>>>> >>>>>>> For any device slice resource management of mdev, sub-function etc, >>> we >>>>>> should be using single kernel interface as devlink [2], [3]. > > This seems impractical, mdevs and SR-IOV are both enumerated, > inspected, created, and removed in sysfs, Both enumerated via sysfs, but VFs are not configured via sysfs. > where do we define what > features are manipulated vis sysfs versus devlink? VFs are configured via well defined, vendor neutral tool iproute2/ip link set <pf_netdev> vf <vf_index> <attribute> <value> This falls short lately for few cases and non-networking or generic VF property configuration, are proposed to be handled by similar 'VF' object using devlink, because they are either pure 'pci vf' property or more device class type VF property such as MAC address or number_of_queues etc. More advance mode of networking VFs, are controlled using netdev representors again in vendor neutral way for last few years. It may be fair to say that mdev subsystem wants to invent new sysfs files for configuration. mdevs, by > definition, are vendor defined "chunks" of a thing. We allow vendor > drivers to define different types, representing different > configurations of these chunks. Often these different types are > incrementally bigger or smaller chunks of these things, but defining > what bigger and smaller means generically across vendors is an > impossible task. Orchestration tools already need to know vendor > specific information in terms of what type of mdev device they want to > create and make use of. The aggregation seems to simply augment that > vendor information, ie. 'type' and 'scale' are separate rather than > combined only behind just 'type'. > >>>>>>> >>>>>>> [1] >>>>>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email- >>> yuval >>>>>>> av@mellanox.com/ [2] >>>>>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html >>>>>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html >>>>>>> >>>>>>> Most modern device configuration that I am aware of is usually done >>> via well >>>>>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and >>> more) or >>>>>> via netlink commands (net, devlink, rdma and more) not via sysfs. >>>>>>> >>>>>> >>>>>> Current vfio/mdev configuration is via documented sysfs ABI instead of >>> other >>>>>> ways. So this adhere to that way to introduce more configurable method >>> on >>>>>> mdev device for standard, it's optional and not actually vendor specific >>> e.g vfio- >>>>>> ap. >>>>>> >>>>> Some unknown/undefined resource as 'aggregate' is just not an ABI. >>>>> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or >>> something similar appropriate to that mdev device class. >>>>> If user wants to set a parameter for a mdev regardless of vendor, they >>> must have single way to do so. > > Aggregation augments type, which is by definition vendor specific. > >>>> >>>> The idea is not specific for some device class, but for each mdev >>>> type's resource, and be optional for each vendor. If more device class >>>> specific way is preferred, then we might have very different ways for >>>> different vendors. Better to avoid that, so here means to aggregate >>>> number of mdev type's resources for target instance, instead of defining >>>> kinds of mdev types for those number of resources. >>>> >>> Parameter or attribute certainly can be optional. >>> But the way to aggregate them should not be vendor specific. >>> Look for some excellent existing examples across subsystems, for example >>> how you create aggregated netdev or block device is not depend on vendor >>> or underlying device type. >> >> I'd like to hear Alex's opinion on this. Today VFIO mdev supports two styles >> of "types" imo: fixed resource definition (most cases) and dynamic resource >> definition (vfio-ap). In fixed style, a type has fixed association to a set of >> vendor specific resources (resourceX=M, resourceY=N, ...). In dynamic case, >> the user is allowed to specify actual resource X/Y/... backing the mdev >> instance post its creation. In either case, the way to identify such association >> or configurable knobs is vendor specific, maybe contained in optional >> attributes (name and description) plus additional info in vendor documents. >> >> Then the user is assumed to clearly understand the implication of the resource >> allocation under a given type, when creating a new mdev under this type. >> >> If this assumption holds true, the aggregated attribute simply provides an >> extension in the same direction of fixed-style types but allowing for more >> flexible linearly-increasing resource allocation. e.g. when using aggregate=2, >> it means creating a instance with resourceX=2M, resourceY=2N, ... under >> the specified type. Along this direction I didn't see the need of well-defined >> vendor specific attributes here. When those are actually required, I suppose >> the dynamic style would better fit. Or if the vendor driver thinks implementing >> such aggregate feature will confuse its type definition, it's optional to not >> doing so anyway. > > Yep, though I don't think we can even define that aggregate=2 indicates > that every resources is doubled, it's going to have vendor specific > meaning. Maybe this is what Parav is rejecting, but I don't see an > alternative. For example, an mdev vGPU might have high level resources > like the number of execution units, graphics memory, display heads, > maximum resolution, etc. Aggregation could affect one or all of these. > Orchestration tools already need to know the vendor specific type of > device they want to create, so it doesn't seem unreasonable that if > they use aggregation that they choose a type that aggregates the > resource(s) they need, but that aggregation is going to be specific to > the type. Potentially as we think about adding "defined" sysfs > attributes for devices we could start with > $SYSFS_DEV_PATH/mdev/aggregation/type, where value written to type is a > vendor specific aggregation of that mdev type. This allows us the > option that we might someday agree on specific resources that might be > aggregated in a common way (ex. ./aggregation/graphics_memory), but I'm > somewhat doubtful those would ever be pursued. Thanks, > My point is, from Zhenyu Wang's example it is certainly incorrect to define mdev sysfs files, as, vendor_foo_mdev.netdev_mac_addr=X vendor_bar_mdev.resource_addr=Y vendor_foo_mdev.netdev_queues=4 vendor_bar_mdev.aggregate=8 Unless this is a miscellaneous (not well defined) parameter of a vendor device. I am 100% sure that consumers of network devices where a PCI PF is sliced into multiple smaller devices, wants to configure these devices in unified way regardless of vendor type. That may not be the case with vGPU mdevs. If Zhenyu Wang proposed to use networking class of mdev device, attributes should have well defined meaning, as it is well known class in linux kernel. mdev should be providing an API to define such mdev config object and all sysfs for such mdev to be created by the mdev core, not by vendor driver.
On Tue, 10 Dec 2019 21:08:29 +0000 Parav Pandit <parav@mellanox.com> wrote: > On 12/10/2019 1:07 PM, Alex Williamson wrote: > > On Tue, 10 Dec 2019 03:33:23 +0000 > > "Tian, Kevin" <kevin.tian@intel.com> wrote: > > > >>> From: Parav Pandit <parav@mellanox.com> > >>> Sent: Saturday, December 7, 2019 1:34 AM > >>> > >>> On 12/6/2019 2:03 AM, Zhenyu Wang wrote: > >>>> On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: > >>>>>>> > >>>>>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: > >>>>>>>>> Hi, > >>>>>>>>> > >>>>>>>>>> -----Original Message----- > >>>>>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> > >>> On > >>>>>>>>>> Behalf Of Zhenyu Wang > >>>>>>>>>> Sent: Thursday, October 24, 2019 12:08 AM > >>>>>>>>>> To: kvm@vger.kernel.org > >>>>>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; > >>>>>>>>>> kevin.tian@intel.com; cohuck@redhat.com > >>>>>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling > >>>>>>>>>> > >>>>>>>>>> Hi, > >>>>>>>>>> > >>>>>>>>>> This is a refresh for previous send of this series. I got > >>>>>>>>>> impression that some SIOV drivers would still deploy their own > >>>>>>>>>> create and config method so stopped effort on this. But seems > >>>>>>>>>> this would still be useful for some other SIOV driver which may > >>>>>>>>>> simply want capability to aggregate resources. So here's refreshed > >>>>>> series. > >>>>>>>>>> > >>>>>>>>>> Current mdev device create interface depends on fixed mdev type, > >>>>>>>>>> which get uuid from user to create instance of mdev device. If > >>>>>>>>>> user wants to use customized number of resource for mdev device, > >>>>>>>>>> then only can create new > >>>>>>>>> Can you please give an example of 'resource'? > >>>>>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' > >>>>>> aggregate'. > >>>>>>>> > >>>>>>>> The resource is vendor device specific, in SIOV spec there's ADI > >>>>>>>> (Assignable Device Interface) definition which could be e.g queue > >>>>>>>> for net device, context for gpu, etc. I just named this interface as > >>>>>> 'aggregate' > >>>>>>>> for aggregation purpose, it's not used in spec doc. > >>>>>>>> > >>>>>>> > >>>>>>> Some 'unknown/undefined' vendor specific resource just doesn't work. > >>>>>>> Orchestration tool doesn't know which resource and what/how to > >>> configure > >>>>>> for which vendor. > >>>>>>> It has to be well defined. > >>>>>>> > >>>>>>> You can also find such discussion in recent lgpu DRM cgroup patches > >>> series > >>>>>> v4. > >>>>>>> > >>>>>>> Exposing networking resource configuration in non-net namespace > >>> aware > >>>>>> mdev sysfs at PCI device level is no-go. > >>>>>>> Adding per file NET_ADMIN or other checks is not the approach we > >>> follow in > >>>>>> kernel. > >>>>>>> > >>>>>>> devlink has been a subsystem though under net, that has very rich > >>> interface > >>>>>> for syscaller, device health, resource management and many more. > >>>>>>> Even though it is used by net driver today, its written for generic device > >>>>>> management at bus/device level. > >>>>>>> > >>>>>>> Yuval has posted patches to manage PCI sub-devices [1] and updated > >>> version > >>>>>> will be posted soon which addresses comments. > > > > Always good to see tools that intend to manage arbitrary devices posted > > only to the netdev list :-\ > > > >>>>>>> > >>>>>>> For any device slice resource management of mdev, sub-function etc, > >>> we > >>>>>> should be using single kernel interface as devlink [2], [3]. > > > > This seems impractical, mdevs and SR-IOV are both enumerated, > > inspected, created, and removed in sysfs, > Both enumerated via sysfs, but VFs are not configured via sysfs. > > > where do we define what > > features are manipulated vis sysfs versus devlink? > > VFs are configured via well defined, vendor neutral tool > iproute2/ip link set <pf_netdev> vf <vf_index> <attribute> <value> > > This falls short lately for few cases and non-networking or generic VF > property configuration, are proposed to be handled by similar 'VF' > object using devlink, because they are either pure 'pci vf' property or > more device class type VF property such as MAC address or > number_of_queues etc. > > More advance mode of networking VFs, are controlled using netdev > representors again in vendor neutral way for last few years. > > It may be fair to say that mdev subsystem wants to invent new sysfs > files for configuration. It seems you're trying to apply rules for classes of devices where configuration features are well defined to an environment where we don't even have classes of devices, let alone agreed features. > mdevs, by > > definition, are vendor defined "chunks" of a thing. We allow vendor > > drivers to define different types, representing different > > configurations of these chunks. Often these different types are > > incrementally bigger or smaller chunks of these things, but defining > > what bigger and smaller means generically across vendors is an > > impossible task. Orchestration tools already need to know vendor > > specific information in terms of what type of mdev device they want to > > create and make use of. The aggregation seems to simply augment that > > vendor information, ie. 'type' and 'scale' are separate rather than > > combined only behind just 'type'. > > > >>>>>>> > >>>>>>> [1] > >>>>>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email- > >>> yuval > >>>>>>> av@mellanox.com/ [2] > >>>>>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html > >>>>>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html > >>>>>>> > >>>>>>> Most modern device configuration that I am aware of is usually done > >>> via well > >>>>>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and > >>> more) or > >>>>>> via netlink commands (net, devlink, rdma and more) not via sysfs. > >>>>>>> > >>>>>> > >>>>>> Current vfio/mdev configuration is via documented sysfs ABI instead of > >>> other > >>>>>> ways. So this adhere to that way to introduce more configurable method > >>> on > >>>>>> mdev device for standard, it's optional and not actually vendor specific > >>> e.g vfio- > >>>>>> ap. > >>>>>> > >>>>> Some unknown/undefined resource as 'aggregate' is just not an ABI. > >>>>> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or > >>> something similar appropriate to that mdev device class. > >>>>> If user wants to set a parameter for a mdev regardless of vendor, they > >>> must have single way to do so. > > > > Aggregation augments type, which is by definition vendor specific. > > > >>>> > >>>> The idea is not specific for some device class, but for each mdev > >>>> type's resource, and be optional for each vendor. If more device class > >>>> specific way is preferred, then we might have very different ways for > >>>> different vendors. Better to avoid that, so here means to aggregate > >>>> number of mdev type's resources for target instance, instead of defining > >>>> kinds of mdev types for those number of resources. > >>>> > >>> Parameter or attribute certainly can be optional. > >>> But the way to aggregate them should not be vendor specific. > >>> Look for some excellent existing examples across subsystems, for example > >>> how you create aggregated netdev or block device is not depend on vendor > >>> or underlying device type. > >> > >> I'd like to hear Alex's opinion on this. Today VFIO mdev supports two styles > >> of "types" imo: fixed resource definition (most cases) and dynamic resource > >> definition (vfio-ap). In fixed style, a type has fixed association to a set of > >> vendor specific resources (resourceX=M, resourceY=N, ...). In dynamic case, > >> the user is allowed to specify actual resource X/Y/... backing the mdev > >> instance post its creation. In either case, the way to identify such association > >> or configurable knobs is vendor specific, maybe contained in optional > >> attributes (name and description) plus additional info in vendor documents. > >> > >> Then the user is assumed to clearly understand the implication of the resource > >> allocation under a given type, when creating a new mdev under this type. > >> > >> If this assumption holds true, the aggregated attribute simply provides an > >> extension in the same direction of fixed-style types but allowing for more > >> flexible linearly-increasing resource allocation. e.g. when using aggregate=2, > >> it means creating a instance with resourceX=2M, resourceY=2N, ... under > >> the specified type. Along this direction I didn't see the need of well-defined > >> vendor specific attributes here. When those are actually required, I suppose > >> the dynamic style would better fit. Or if the vendor driver thinks implementing > >> such aggregate feature will confuse its type definition, it's optional to not > >> doing so anyway. > > > > Yep, though I don't think we can even define that aggregate=2 indicates > > that every resources is doubled, it's going to have vendor specific > > meaning. Maybe this is what Parav is rejecting, but I don't see an > > alternative. For example, an mdev vGPU might have high level resources > > like the number of execution units, graphics memory, display heads, > > maximum resolution, etc. Aggregation could affect one or all of these. > > Orchestration tools already need to know the vendor specific type of > > device they want to create, so it doesn't seem unreasonable that if > > they use aggregation that they choose a type that aggregates the > > resource(s) they need, but that aggregation is going to be specific to > > the type. Potentially as we think about adding "defined" sysfs > > attributes for devices we could start with > > $SYSFS_DEV_PATH/mdev/aggregation/type, where value written to type is a > > vendor specific aggregation of that mdev type. This allows us the > > option that we might someday agree on specific resources that might be > > aggregated in a common way (ex. ./aggregation/graphics_memory), but I'm > > somewhat doubtful those would ever be pursued. Thanks, > > > > My point is, from Zhenyu Wang's example it is certainly incorrect to > define mdev sysfs files, as, > > vendor_foo_mdev.netdev_mac_addr=X > vendor_bar_mdev.resource_addr=Y > > vendor_foo_mdev.netdev_queues=4 > vendor_bar_mdev.aggregate=8 > > Unless this is a miscellaneous (not well defined) parameter of a vendor > device. I certainly think it's wrong to associate a "netdev" property with something that the kernel only knows as an opaque device. But that's really the issue, mdevs are opaque devices as far as the host kernel is concerned. Since we seem to have landed on mdev being used exclusively for vfio, the only thing we really know about an mdev generically is which vfio bus driver API the device uses. Any association of an mdev to a GPU, NIC, HBA, or other accelerator or I/O interface is strictly known by the user/admin's interpretation of the vendor specific type. > I am 100% sure that consumers of network devices where a PCI PF is > sliced into multiple smaller devices, wants to configure these devices > in unified way regardless of vendor type. > That may not be the case with vGPU mdevs. I don't know about devlink, but iirc the ip command operates on a netdev PF in order to, for example, assign MAC addresses to the VFs. We have no guarantee with mdevs that there's a parent netdev device for such an interface. The parent device might be an FPGA where one type it's able to expose looks like a NIC. How do you envision devlink/ip interacting with something like that? Using common tools to set networking properties on a device that the host kernel fundamentally does not know is a networking device is... difficult. > If Zhenyu Wang proposed to use networking class of mdev device, > attributes should have well defined meaning, as it is well known class > in linux kernel. > mdev should be providing an API to define such mdev config object and > all sysfs for such mdev to be created by the mdev core, not by vendor > driver. But of course there is no "networking class of mdev device". Instead there are mdev devices that might be NICs, but that's for the admin and user to care about. If you have an interface in mind for how devlink is going to learn about mdev device and set properties, please share. It's not clear to me if we need to design something to be compatible with devlink or devlink needs to learn how to do certain things on mdev devices (does devlink want to become a vfio userspace device driver in order to probe the type of an mdev device? That'll be hard given some of the backdoor userspace dependencies of existing vGPU mdevs). Thanks, Alex
On 12/10/2019 4:08 PM, Alex Williamson wrote: > On Tue, 10 Dec 2019 21:08:29 +0000 > Parav Pandit <parav@mellanox.com> wrote: > >> On 12/10/2019 1:07 PM, Alex Williamson wrote: >>> On Tue, 10 Dec 2019 03:33:23 +0000 >>> "Tian, Kevin" <kevin.tian@intel.com> wrote: >>> >>>>> From: Parav Pandit <parav@mellanox.com> >>>>> Sent: Saturday, December 7, 2019 1:34 AM >>>>> >>>>> On 12/6/2019 2:03 AM, Zhenyu Wang wrote: >>>>>> On 2019.12.05 18:59:36 +0000, Parav Pandit wrote: >>>>>>>>> >>>>>>>>>> On 2019.11.07 20:37:49 +0000, Parav Pandit wrote: >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>>> -----Original Message----- >>>>>>>>>>>> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> >>>>> On >>>>>>>>>>>> Behalf Of Zhenyu Wang >>>>>>>>>>>> Sent: Thursday, October 24, 2019 12:08 AM >>>>>>>>>>>> To: kvm@vger.kernel.org >>>>>>>>>>>> Cc: alex.williamson@redhat.com; kwankhede@nvidia.com; >>>>>>>>>>>> kevin.tian@intel.com; cohuck@redhat.com >>>>>>>>>>>> Subject: [PATCH 0/6] VFIO mdev aggregated resources handling >>>>>>>>>>>> >>>>>>>>>>>> Hi, >>>>>>>>>>>> >>>>>>>>>>>> This is a refresh for previous send of this series. I got >>>>>>>>>>>> impression that some SIOV drivers would still deploy their own >>>>>>>>>>>> create and config method so stopped effort on this. But seems >>>>>>>>>>>> this would still be useful for some other SIOV driver which may >>>>>>>>>>>> simply want capability to aggregate resources. So here's refreshed >>>>>>>> series. >>>>>>>>>>>> >>>>>>>>>>>> Current mdev device create interface depends on fixed mdev type, >>>>>>>>>>>> which get uuid from user to create instance of mdev device. If >>>>>>>>>>>> user wants to use customized number of resource for mdev device, >>>>>>>>>>>> then only can create new >>>>>>>>>>> Can you please give an example of 'resource'? >>>>>>>>>>> When I grep [1], [2] and [3], I couldn't find anything related to ' >>>>>>>> aggregate'. >>>>>>>>>> >>>>>>>>>> The resource is vendor device specific, in SIOV spec there's ADI >>>>>>>>>> (Assignable Device Interface) definition which could be e.g queue >>>>>>>>>> for net device, context for gpu, etc. I just named this interface as >>>>>>>> 'aggregate' >>>>>>>>>> for aggregation purpose, it's not used in spec doc. >>>>>>>>>> >>>>>>>>> >>>>>>>>> Some 'unknown/undefined' vendor specific resource just doesn't work. >>>>>>>>> Orchestration tool doesn't know which resource and what/how to >>>>> configure >>>>>>>> for which vendor. >>>>>>>>> It has to be well defined. >>>>>>>>> >>>>>>>>> You can also find such discussion in recent lgpu DRM cgroup patches >>>>> series >>>>>>>> v4. >>>>>>>>> >>>>>>>>> Exposing networking resource configuration in non-net namespace >>>>> aware >>>>>>>> mdev sysfs at PCI device level is no-go. >>>>>>>>> Adding per file NET_ADMIN or other checks is not the approach we >>>>> follow in >>>>>>>> kernel. >>>>>>>>> >>>>>>>>> devlink has been a subsystem though under net, that has very rich >>>>> interface >>>>>>>> for syscaller, device health, resource management and many more. >>>>>>>>> Even though it is used by net driver today, its written for generic device >>>>>>>> management at bus/device level. >>>>>>>>> >>>>>>>>> Yuval has posted patches to manage PCI sub-devices [1] and updated >>>>> version >>>>>>>> will be posted soon which addresses comments. >>> >>> Always good to see tools that intend to manage arbitrary devices posted >>> only to the netdev list :-\ >>> >>>>>>>>> >>>>>>>>> For any device slice resource management of mdev, sub-function etc, >>>>> we >>>>>>>> should be using single kernel interface as devlink [2], [3]. >>> >>> This seems impractical, mdevs and SR-IOV are both enumerated, >>> inspected, created, and removed in sysfs, >> Both enumerated via sysfs, but VFs are not configured via sysfs. >> >>> where do we define what >>> features are manipulated vis sysfs versus devlink? >> >> VFs are configured via well defined, vendor neutral tool >> iproute2/ip link set <pf_netdev> vf <vf_index> <attribute> <value> >> >> This falls short lately for few cases and non-networking or generic VF >> property configuration, are proposed to be handled by similar 'VF' >> object using devlink, because they are either pure 'pci vf' property or >> more device class type VF property such as MAC address or >> number_of_queues etc. >> >> More advance mode of networking VFs, are controlled using netdev >> representors again in vendor neutral way for last few years. >> >> It may be fair to say that mdev subsystem wants to invent new sysfs >> files for configuration. > > It seems you're trying to apply rules for classes of devices where > configuration features are well defined to an environment where we > don't even have classes of devices, let alone agreed features. > >> mdevs, by >>> definition, are vendor defined "chunks" of a thing. We allow vendor >>> drivers to define different types, representing different >>> configurations of these chunks. Often these different types are >>> incrementally bigger or smaller chunks of these things, but defining >>> what bigger and smaller means generically across vendors is an >>> impossible task. Orchestration tools already need to know vendor >>> specific information in terms of what type of mdev device they want to >>> create and make use of. The aggregation seems to simply augment that >>> vendor information, ie. 'type' and 'scale' are separate rather than >>> combined only behind just 'type'. >>> >>>>>>>>> >>>>>>>>> [1] >>>>>>>>> https://lore.kernel.org/netdev/1573229926-30040-1-git-send-email- >>>>> yuval >>>>>>>>> av@mellanox.com/ [2] >>>>>>>>> http://man7.org/linux/man-pages/man8/devlink-dev.8.html >>>>>>>>> [3] http://man7.org/linux/man-pages/man8/devlink-resource.8.html >>>>>>>>> >>>>>>>>> Most modern device configuration that I am aware of is usually done >>>>> via well >>>>>>>> defined ioctl() of the subsystem (vhost, virtio, vfio, rdma, nvme and >>>>> more) or >>>>>>>> via netlink commands (net, devlink, rdma and more) not via sysfs. >>>>>>>>> >>>>>>>> >>>>>>>> Current vfio/mdev configuration is via documented sysfs ABI instead of >>>>> other >>>>>>>> ways. So this adhere to that way to introduce more configurable method >>>>> on >>>>>>>> mdev device for standard, it's optional and not actually vendor specific >>>>> e.g vfio- >>>>>>>> ap. >>>>>>>> >>>>>>> Some unknown/undefined resource as 'aggregate' is just not an ABI. >>>>>>> It has to be well defined, as 'hardware_address', 'num_netdev_sqs' or >>>>> something similar appropriate to that mdev device class. >>>>>>> If user wants to set a parameter for a mdev regardless of vendor, they >>>>> must have single way to do so. >>> >>> Aggregation augments type, which is by definition vendor specific. >>> >>>>>> >>>>>> The idea is not specific for some device class, but for each mdev >>>>>> type's resource, and be optional for each vendor. If more device class >>>>>> specific way is preferred, then we might have very different ways for >>>>>> different vendors. Better to avoid that, so here means to aggregate >>>>>> number of mdev type's resources for target instance, instead of defining >>>>>> kinds of mdev types for those number of resources. >>>>>> >>>>> Parameter or attribute certainly can be optional. >>>>> But the way to aggregate them should not be vendor specific. >>>>> Look for some excellent existing examples across subsystems, for example >>>>> how you create aggregated netdev or block device is not depend on vendor >>>>> or underlying device type. >>>> >>>> I'd like to hear Alex's opinion on this. Today VFIO mdev supports two styles >>>> of "types" imo: fixed resource definition (most cases) and dynamic resource >>>> definition (vfio-ap). In fixed style, a type has fixed association to a set of >>>> vendor specific resources (resourceX=M, resourceY=N, ...). In dynamic case, >>>> the user is allowed to specify actual resource X/Y/... backing the mdev >>>> instance post its creation. In either case, the way to identify such association >>>> or configurable knobs is vendor specific, maybe contained in optional >>>> attributes (name and description) plus additional info in vendor documents. >>>> >>>> Then the user is assumed to clearly understand the implication of the resource >>>> allocation under a given type, when creating a new mdev under this type. >>>> >>>> If this assumption holds true, the aggregated attribute simply provides an >>>> extension in the same direction of fixed-style types but allowing for more >>>> flexible linearly-increasing resource allocation. e.g. when using aggregate=2, >>>> it means creating a instance with resourceX=2M, resourceY=2N, ... under >>>> the specified type. Along this direction I didn't see the need of well-defined >>>> vendor specific attributes here. When those are actually required, I suppose >>>> the dynamic style would better fit. Or if the vendor driver thinks implementing >>>> such aggregate feature will confuse its type definition, it's optional to not >>>> doing so anyway. >>> >>> Yep, though I don't think we can even define that aggregate=2 indicates >>> that every resources is doubled, it's going to have vendor specific >>> meaning. Maybe this is what Parav is rejecting, but I don't see an >>> alternative. For example, an mdev vGPU might have high level resources >>> like the number of execution units, graphics memory, display heads, >>> maximum resolution, etc. Aggregation could affect one or all of these. >>> Orchestration tools already need to know the vendor specific type of >>> device they want to create, so it doesn't seem unreasonable that if >>> they use aggregation that they choose a type that aggregates the >>> resource(s) they need, but that aggregation is going to be specific to >>> the type. Potentially as we think about adding "defined" sysfs >>> attributes for devices we could start with >>> $SYSFS_DEV_PATH/mdev/aggregation/type, where value written to type is a >>> vendor specific aggregation of that mdev type. This allows us the >>> option that we might someday agree on specific resources that might be >>> aggregated in a common way (ex. ./aggregation/graphics_memory), but I'm >>> somewhat doubtful those would ever be pursued. Thanks, >>> >> >> My point is, from Zhenyu Wang's example it is certainly incorrect to >> define mdev sysfs files, as, >> >> vendor_foo_mdev.netdev_mac_addr=X >> vendor_bar_mdev.resource_addr=Y >> >> vendor_foo_mdev.netdev_queues=4 >> vendor_bar_mdev.aggregate=8 >> >> Unless this is a miscellaneous (not well defined) parameter of a vendor >> device. > > I certainly think it's wrong to associate a "netdev" property with > something that the kernel only knows as an opaque device. But that's > really the issue, mdevs are opaque devices as far as the host kernel is > concerned. Since we seem to have landed on mdev being used exclusively > for vfio, the only thing we really know about an mdev generically is > which vfio bus driver API the device uses. Any association of an mdev > to a GPU, NIC, HBA, or other accelerator or I/O interface is strictly > known by the user/admin's interpretation of the vendor specific type. > >> I am 100% sure that consumers of network devices where a PCI PF is >> sliced into multiple smaller devices, wants to configure these devices >> in unified way regardless of vendor type. >> That may not be the case with vGPU mdevs. > > I don't know about devlink, but iirc the ip command operates on a > netdev PF in order to, for example, assign MAC addresses to the VFs. > We have no guarantee with mdevs that there's a parent netdev device for > such an interface. Right. ip link works on netdev. But devlink works on devlink instance such as bus/device. Here is an example from one system $ devlink dev show pci/0000:06:00.0 pci/0000:06:00.1 Here two devlink instance for a PCI device is registered and this devlink device has params, ports, health monitoring, register dumps and lot more. The parent device might be an FPGA where one type > it's able to expose looks like a NIC. How do you envision devlink/ip > interacting with something like that? Using common tools to set > networking properties on a device that the host kernel fundamentally > does not know is a networking device is... difficult. > If it is exposing FPGA NIC and it needs to be configured, as individual mdev devices, my series of sub-function is perfect example of it, where lifecycle of mdev is done through the mdev subsystem, and all params configured using devlink. Series was NACKed for different reason which anyway still holds true regardless of this discussion. >> If Zhenyu Wang proposed to use networking class of mdev device, >> attributes should have well defined meaning, as it is well known class >> in linux kernel. >> mdev should be providing an API to define such mdev config object and >> all sysfs for such mdev to be created by the mdev core, not by vendor >> driver. > > But of course there is no "networking class of mdev device". Instead > there are mdev devices that might be NICs, Such object should be created as pre-patch if this is networking class mdev and configure it using such method. Things will be lot more clear. > but that's for the admin and > user to care about. Admin and user to care about but kernel is the one to provide config interface so program 'net class mdev device' using one command. > If you have an interface in mind for how devlink > is going to learn about mdev device and set properties, please share. I shared the working patches of mdev nics as mellanox sub-functions. It is good starting point. Since input was to use devlink interface for sub-function/mediated/slice NICs, I have revised the RFC to do so, instead of mdev way. I am happy to share once we finish internal review. I wish I can share before Christmas holidays. > It's not clear to me if we need to design something to be compatible > with devlink or devlink needs to learn how to do certain things on mdev > devices (does devlink want to become a vfio userspace device driver in > order to probe the type of an mdev device? That'll be hard given some > of the backdoor userspace dependencies of existing vGPU mdevs). Thanks, Lets assume for a moment that devlink may not be the tool for mdev device configuration. Even in such case, my ask is to clearly define config params via ioctl() or sysfs as exactly what that param is. Exposing FPGA NIC net device mac address and other things in sysfs which is not protected by net namespace is security bug.
Hi, This is a refresh for previous send of this series. I got impression that some SIOV drivers would still deploy their own create and config method so stopped effort on this. But seems this would still be useful for some other SIOV driver which may simply want capability to aggregate resources. So here's refreshed series. Current mdev device create interface depends on fixed mdev type, which get uuid from user to create instance of mdev device. If user wants to use customized number of resource for mdev device, then only can create new mdev type for that which may not be flexible. This requirement comes not only from to be able to allocate flexible resources for KVMGT, but also from Intel scalable IO virtualization which would use vfio/mdev to be able to allocate arbitrary resources on mdev instance. More info on [1] [2] [3]. To allow to create user defined resources for mdev, it trys to extend mdev create interface by adding new "aggregate=xxx" parameter following UUID, for target mdev type if aggregation is supported, it can create new mdev device which contains resources combined by number of instances, e.g echo "<uuid>,aggregate=10" > create VM manager e.g libvirt can check mdev type with "aggregation" attribute which can support this setting. If no "aggregation" attribute found for mdev type, previous behavior is still kept for one instance allocation. And new sysfs attribute "aggregated_instances" is created for each mdev device to show allocated number. References: [1] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification [2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification [3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf Zhenyu Wang (6): vfio/mdev: Add new "aggregate" parameter for mdev create vfio/mdev: Add "aggregation" attribute for supported mdev type vfio/mdev: Add "aggregated_instances" attribute for supported mdev device Documentation/driver-api/vfio-mediated-device.rst: Update for vfio/mdev aggregation support Documentation/ABI/testing/sysfs-bus-vfio-mdev: Update for vfio/mdev aggregation support drm/i915/gvt: Add new type with aggregation support Documentation/ABI/testing/sysfs-bus-vfio-mdev | 24 ++++++ .../driver-api/vfio-mediated-device.rst | 23 ++++++ drivers/gpu/drm/i915/gvt/gvt.c | 4 +- drivers/gpu/drm/i915/gvt/gvt.h | 11 ++- drivers/gpu/drm/i915/gvt/kvmgt.c | 53 ++++++++++++- drivers/gpu/drm/i915/gvt/vgpu.c | 56 ++++++++++++- drivers/vfio/mdev/mdev_core.c | 36 ++++++++- drivers/vfio/mdev/mdev_private.h | 6 +- drivers/vfio/mdev/mdev_sysfs.c | 79 ++++++++++++++++++- include/linux/mdev.h | 19 +++++ 10 files changed, 294 insertions(+), 17 deletions(-)