| Message ID | 20240712114704.8708-1-joao.m.martins@oracle.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | hw/iommufd: IOMMUFD Dirty Tracking | expand |
>-----Original Message----- >From: Joao Martins <joao.m.martins@oracle.com> >Subject: [PATCH v4 00/12] hw/iommufd: IOMMUFD Dirty Tracking > >This small series adds support for IOMMU dirty tracking support via the >IOMMUFD backend. The hardware capability is available on most recent x86 >hardware. The series is divided organized as follows: > >* Patch 1-2: Fixes a regression into mdev support with IOMMUFD. This > one is independent of the series but happened to cross it > while testing mdev with this series I guess VFIO ap/ccw may need fixes too. Will you help on that or I can take it if you want to focus on dirty tracking. The fix may be trivial, just assign VFIODevice->mdev = true. Thanks Zhenzhong > >* Patch 3: Adds a support to iommufd_get_device_info() for capabilities > >* Patches 4 - 10: IOMMUFD backend support for dirty tracking; > >Introduce auto domains -- Patch 5 goes into more detail, but the gist is that >we will find and attach a device to a compatible IOMMU domain, or allocate >a new >hardware pagetable *or* rely on kernel IOAS attach (for mdevs). Afterwards >the >workflow is relatively simple: > >1) Probe device and allow dirty tracking in the HWPT >2) Toggling dirty tracking on/off >3) Read-and-clear of Dirty IOVAs > >The heuristics selected for (1) were to always request the HWPT for >dirty tracking if supported, or rely on device dirty page tracking. This >is a little simplistic and we aren't necessarily utilizing IOMMU dirty >tracking even if we ask during hwpt allocation. > >The unmap case is deferred until further vIOMMU support with migration >is added[3] which will then introduce the usage of >IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR in GET_DIRTY_BITMAP ioctl >in the >dma unmap bitmap flow. > >* Patches 11-12: Don't block live migration where there's no VF dirty >tracker, considering that we have IOMMU dirty tracking. > >Comments and feedback appreciated. Thanks for all the review thus far! > >Cheers, > Joao > >P.S. Suggest linux-next (or future v6.11) as hypervisor kernel as there's >some bugs fixed there with regards to IOMMU hugepage dirty tracking. > >Changes since v3[5]: >* Skip HostIOMMUDevice::realize for mdev, and introduce a helper to check >if the VFIO > device is mdev. (Zhenzhong) >* Skip setting IOMMU device for mdev (Zhenzhong) >* Add Zhenzhong review tag in patch 3 >* Utilize vbasedev::bcontainer::dirty_pages_supported instead of >introducing > a new HostIOMMUDevice capability and thus remove the cap patch from >the series (Zhenzhong) >* Move the HostIOMMUDevice::realize() to be part of VFIODevice >initialization in attach_device() >while skipping it all together for mdev. (Cedric) >* Due to the previous item, had to remove aw_bits because it depends on >device attach being >finished, instead defer it to when get_cap() gets called. >* Skip auto domains for mdev instead of purposedly erroring out >(Zhenzhong) >* Pass errp in all cases, and instead just free the error in case of -EINVAL > in most of all patches, and also pass Error* in >iommufd_backend_alloc_hwpt() amd > set/query dirty. This is made better thanks in part to skipping auto domains >for mdev (Cedric) > >Changes since RFCv2[4]: >* Always allocate hwpt with IOMMU_HWPT_ALLOC_DIRTY_TRACKING even >if >we end up not actually toggling dirty tracking. (Avihai) >* Fix error handling widely in auto domains logic and all patches (Avihai) >* Reuse iommufd_backend_get_device_info() for capabilities (Zhenzhong) >* New patches 1 and 2 taking into consideration previous comments. >* Store hwpt::flags to know if we have dirty tracking (Avihai) >* New patch 8, that allows to query dirty tracking support after >provisioning. This is a cleaner way to check IOMMU dirty tracking support >when vfio::migration is iniitalized, as opposed to RFCv2 via device caps. >device caps way is still used because at vfio attach we aren't yet with >a fully initialized migration state. >* Adopt error propagation in query,set dirty tracking >* Misc improvements overall broadly and Avihai >* Drop hugepages as it's a bit unrelated; I can pursue that patch >* separately. The main motivation is to provide a way to test >without hugepages similar to what vfio_type1_iommu.disable_hugepages=1 >does. > >Changes since RFCv1[2]: >* Remove intel/amd dirty tracking emulation enabling >* Remove the dirtyrate improvement for VF/IOMMU dirty tracking >[Will pursue these two in separate series] >* Introduce auto domains support >* Enforce dirty tracking following the IOMMUFD UAPI for this >* Add support for toggling hugepages in IOMMUFD >* Auto enable support when VF supports migration to use IOMMU >when it doesn't have VF dirty tracking >* Add a parameter to toggle VF dirty tracking > >[0] https://lore.kernel.org/qemu-devel/20240201072818.327930-1- >zhenzhong.duan@intel.com/ >[1] https://lore.kernel.org/qemu-devel/20240201072818.327930-10- >zhenzhong.duan@intel.com/ >[2] https://lore.kernel.org/qemu-devel/20220428211351.3897-1- >joao.m.martins@oracle.com/ >[3] https://lore.kernel.org/qemu-devel/20230622214845.3980-1- >joao.m.martins@oracle.com/ >[4] https://lore.kernel.org/qemu-devel/20240212135643.5858-1- >joao.m.martins@oracle.com/ >[5] https://lore.kernel.org/qemu-devel/20240708143420.16953-1- >joao.m.martins@oracle.com/ > >Joao Martins (12): > vfio/pci: Extract mdev check into an helper > vfio/iommufd: Don't initialize nor set a HOST_IOMMU_DEVICE with mdev > backends/iommufd: Extend iommufd_backend_get_device_info() to fetch >HW > capabilities > vfio/iommufd: Return errno in iommufd_cdev_attach_ioas_hwpt() > vfio/iommufd: Introduce auto domain creation > vfio/{iommufd,container}: Remove caps::aw_bits > vfio/{iommufd,container}: Initialize HostIOMMUDeviceCaps during > attach_device() > vfio/iommufd: Probe and request hwpt dirty tracking capability > vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support > vfio/iommufd: Implement VFIOIOMMUClass::query_dirty_bitmap support > vfio/migration: Don't block migration device dirty tracking is > unsupported > vfio/common: Allow disabling device dirty page tracking > > include/hw/vfio/vfio-common.h | 13 +++ > include/sysemu/host_iommu_device.h | 2 +- > include/sysemu/iommufd.h | 14 ++- > backends/iommufd.c | 89 ++++++++++++++- > hw/vfio/common.c | 17 +-- > hw/vfio/container.c | 11 +- > hw/vfio/helpers.c | 18 +++ > hw/vfio/iommufd.c | 178 ++++++++++++++++++++++++++++- > hw/vfio/migration.c | 4 +- > hw/vfio/pci.c | 22 ++-- > backends/trace-events | 3 + > 11 files changed, 339 insertions(+), 32 deletions(-) > >-- >2.17.2
On 16/07/2024 09:20, Duan, Zhenzhong wrote: > > >> -----Original Message----- >> From: Joao Martins <joao.m.martins@oracle.com> >> Subject: [PATCH v4 00/12] hw/iommufd: IOMMUFD Dirty Tracking >> >> This small series adds support for IOMMU dirty tracking support via the >> IOMMUFD backend. The hardware capability is available on most recent x86 >> hardware. The series is divided organized as follows: >> >> * Patch 1-2: Fixes a regression into mdev support with IOMMUFD. This >> one is independent of the series but happened to cross it >> while testing mdev with this series > > I guess VFIO ap/ccw may need fixes too. > Will you help on that or I can take it if you want to focus on dirty tracking. > The fix may be trivial, just assign VFIODevice->mdev = true. > If you have something in mind already by all means go ahead. But from the code are we sure these are mdev bus devices? Certainly are grepping with 'mdev' but unclear if that's abbreviation for 'My Device' or actually bus mdev/mediated-device?
>-----Original Message----- >From: Joao Martins <joao.m.martins@oracle.com> >Subject: Re: [PATCH v4 00/12] hw/iommufd: IOMMUFD Dirty Tracking > >On 16/07/2024 09:20, Duan, Zhenzhong wrote: >> >> >>> -----Original Message----- >>> From: Joao Martins <joao.m.martins@oracle.com> >>> Subject: [PATCH v4 00/12] hw/iommufd: IOMMUFD Dirty Tracking >>> >>> This small series adds support for IOMMU dirty tracking support via the >>> IOMMUFD backend. The hardware capability is available on most recent >x86 >>> hardware. The series is divided organized as follows: >>> >>> * Patch 1-2: Fixes a regression into mdev support with IOMMUFD. This >>> one is independent of the series but happened to cross it >>> while testing mdev with this series >> >> I guess VFIO ap/ccw may need fixes too. >> Will you help on that or I can take it if you want to focus on dirty tracking. >> The fix may be trivial, just assign VFIODevice->mdev = true. >> > >If you have something in mind already by all means go ahead. OK, will be after your 'dirty tracking' v5 as there is dependency. > >But from the code are we sure these are mdev bus devices? Certainly are >grepping >with 'mdev' but unclear if that's abbreviation for 'My Device' or actually bus >mdev/mediated-device? I think so, docs/system/s390x/vfio-[ap|ccw].rst shows /sys/bus/mdev Thanks Zhenzhong
This small series adds support for IOMMU dirty tracking support via the IOMMUFD backend. The hardware capability is available on most recent x86 hardware. The series is divided organized as follows: * Patch 1-2: Fixes a regression into mdev support with IOMMUFD. This one is independent of the series but happened to cross it while testing mdev with this series * Patch 3: Adds a support to iommufd_get_device_info() for capabilities * Patches 4 - 10: IOMMUFD backend support for dirty tracking; Introduce auto domains -- Patch 5 goes into more detail, but the gist is that we will find and attach a device to a compatible IOMMU domain, or allocate a new hardware pagetable *or* rely on kernel IOAS attach (for mdevs). Afterwards the workflow is relatively simple: 1) Probe device and allow dirty tracking in the HWPT 2) Toggling dirty tracking on/off 3) Read-and-clear of Dirty IOVAs The heuristics selected for (1) were to always request the HWPT for dirty tracking if supported, or rely on device dirty page tracking. This is a little simplistic and we aren't necessarily utilizing IOMMU dirty tracking even if we ask during hwpt allocation. The unmap case is deferred until further vIOMMU support with migration is added[3] which will then introduce the usage of IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR in GET_DIRTY_BITMAP ioctl in the dma unmap bitmap flow. * Patches 11-12: Don't block live migration where there's no VF dirty tracker, considering that we have IOMMU dirty tracking. Comments and feedback appreciated. Thanks for all the review thus far! Cheers, Joao P.S. Suggest linux-next (or future v6.11) as hypervisor kernel as there's some bugs fixed there with regards to IOMMU hugepage dirty tracking. Changes since v3[5]: * Skip HostIOMMUDevice::realize for mdev, and introduce a helper to check if the VFIO device is mdev. (Zhenzhong) * Skip setting IOMMU device for mdev (Zhenzhong) * Add Zhenzhong review tag in patch 3 * Utilize vbasedev::bcontainer::dirty_pages_supported instead of introducing a new HostIOMMUDevice capability and thus remove the cap patch from the series (Zhenzhong) * Move the HostIOMMUDevice::realize() to be part of VFIODevice initialization in attach_device() while skipping it all together for mdev. (Cedric) * Due to the previous item, had to remove aw_bits because it depends on device attach being finished, instead defer it to when get_cap() gets called. * Skip auto domains for mdev instead of purposedly erroring out (Zhenzhong) * Pass errp in all cases, and instead just free the error in case of -EINVAL in most of all patches, and also pass Error* in iommufd_backend_alloc_hwpt() amd set/query dirty. This is made better thanks in part to skipping auto domains for mdev (Cedric) Changes since RFCv2[4]: * Always allocate hwpt with IOMMU_HWPT_ALLOC_DIRTY_TRACKING even if we end up not actually toggling dirty tracking. (Avihai) * Fix error handling widely in auto domains logic and all patches (Avihai) * Reuse iommufd_backend_get_device_info() for capabilities (Zhenzhong) * New patches 1 and 2 taking into consideration previous comments. * Store hwpt::flags to know if we have dirty tracking (Avihai) * New patch 8, that allows to query dirty tracking support after provisioning. This is a cleaner way to check IOMMU dirty tracking support when vfio::migration is iniitalized, as opposed to RFCv2 via device caps. device caps way is still used because at vfio attach we aren't yet with a fully initialized migration state. * Adopt error propagation in query,set dirty tracking * Misc improvements overall broadly and Avihai * Drop hugepages as it's a bit unrelated; I can pursue that patch * separately. The main motivation is to provide a way to test without hugepages similar to what vfio_type1_iommu.disable_hugepages=1 does. Changes since RFCv1[2]: * Remove intel/amd dirty tracking emulation enabling * Remove the dirtyrate improvement for VF/IOMMU dirty tracking [Will pursue these two in separate series] * Introduce auto domains support * Enforce dirty tracking following the IOMMUFD UAPI for this * Add support for toggling hugepages in IOMMUFD * Auto enable support when VF supports migration to use IOMMU when it doesn't have VF dirty tracking * Add a parameter to toggle VF dirty tracking [0] https://lore.kernel.org/qemu-devel/20240201072818.327930-1-zhenzhong.duan@intel.com/ [1] https://lore.kernel.org/qemu-devel/20240201072818.327930-10-zhenzhong.duan@intel.com/ [2] https://lore.kernel.org/qemu-devel/20220428211351.3897-1-joao.m.martins@oracle.com/ [3] https://lore.kernel.org/qemu-devel/20230622214845.3980-1-joao.m.martins@oracle.com/ [4] https://lore.kernel.org/qemu-devel/20240212135643.5858-1-joao.m.martins@oracle.com/ [5] https://lore.kernel.org/qemu-devel/20240708143420.16953-1-joao.m.martins@oracle.com/ Joao Martins (12): vfio/pci: Extract mdev check into an helper vfio/iommufd: Don't initialize nor set a HOST_IOMMU_DEVICE with mdev backends/iommufd: Extend iommufd_backend_get_device_info() to fetch HW capabilities vfio/iommufd: Return errno in iommufd_cdev_attach_ioas_hwpt() vfio/iommufd: Introduce auto domain creation vfio/{iommufd,container}: Remove caps::aw_bits vfio/{iommufd,container}: Initialize HostIOMMUDeviceCaps during attach_device() vfio/iommufd: Probe and request hwpt dirty tracking capability vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support vfio/iommufd: Implement VFIOIOMMUClass::query_dirty_bitmap support vfio/migration: Don't block migration device dirty tracking is unsupported vfio/common: Allow disabling device dirty page tracking include/hw/vfio/vfio-common.h | 13 +++ include/sysemu/host_iommu_device.h | 2 +- include/sysemu/iommufd.h | 14 ++- backends/iommufd.c | 89 ++++++++++++++- hw/vfio/common.c | 17 +-- hw/vfio/container.c | 11 +- hw/vfio/helpers.c | 18 +++ hw/vfio/iommufd.c | 178 ++++++++++++++++++++++++++++- hw/vfio/migration.c | 4 +- hw/vfio/pci.c | 22 ++-- backends/trace-events | 3 + 11 files changed, 339 insertions(+), 32 deletions(-)