| Message ID | 1432893209-27313-3-git-send-email-andre.przywara@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Eric Auger <eric.auger@linaro.org> On 05/29/2015 11:53 AM, Andre Przywara wrote: > The ARM GICv3 ITS MSI controller requires a device ID to be able to > assign the proper interrupt vector. On real hardware, this ID is > sampled from the bus. To be able to emulate an ITS controller, extend > the KVM MSI interface to let userspace provide such a device ID. For > PCI devices, the device ID is simply the 16-bit bus-device-function > triplet, which should be easily available to the userland tool. > > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > --- > Documentation/virtual/kvm/api.txt | 8 ++++++-- > include/uapi/linux/kvm.h | 4 +++- > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 9fa2bf8..891d64a 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2121,10 +2121,14 @@ struct kvm_msi { > __u32 address_hi; > __u32 data; > __u32 flags; > - __u8 pad[16]; > + __u32 devid; > + __u8 pad[12]; > }; > > -No flags are defined so far. The corresponding field must be 0. > +flags: KVM_MSI_VALID_DEVID: devid is valid, otherwise ignored. > +devid: If KVM_MSI_VALID_DEVID is set, contains a value to identify the device > + that wrote the MSI message. For PCI, this is usually a BFD > + identifier in the lower 16 bits. > > > 4.71 KVM_CREATE_PIT2 > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 4b60056..2a23705 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -965,12 +965,14 @@ struct kvm_one_reg { > __u64 addr; > }; > > +#define KVM_MSI_VALID_DEVID (1U << 0) > struct kvm_msi { > __u32 address_lo; > __u32 address_hi; > __u32 data; > __u32 flags; > - __u8 pad[16]; > + __u32 devid; > + __u8 pad[12]; > }; > > struct kvm_arm_device_addr { > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, May 29, 2015 at 10:53:18AM +0100, Andre Przywara wrote: > The ARM GICv3 ITS MSI controller requires a device ID to be able to > assign the proper interrupt vector. On real hardware, this ID is > sampled from the bus. To be able to emulate an ITS controller, extend > the KVM MSI interface to let userspace provide such a device ID. For > PCI devices, the device ID is simply the 16-bit bus-device-function > triplet, which should be easily available to the userland tool. > > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > --- > Documentation/virtual/kvm/api.txt | 8 ++++++-- > include/uapi/linux/kvm.h | 4 +++- > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 9fa2bf8..891d64a 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2121,10 +2121,14 @@ struct kvm_msi { > __u32 address_hi; > __u32 data; > __u32 flags; > - __u8 pad[16]; > + __u32 devid; > + __u8 pad[12]; > }; > > -No flags are defined so far. The corresponding field must be 0. > +flags: KVM_MSI_VALID_DEVID: devid is valid, otherwise ignored. I don't see what the 'otherwise ignored' part of the sentence here is meant to say, that the flags field is otherwise ignored for other value? That's not what the current API doc specifies, it specifies that the remainder of the field must be 0. > +devid: If KVM_MSI_VALID_DEVID is set, contains a value to identify the device > + that wrote the MSI message. For PCI, this is usually a BFD > + identifier in the lower 16 bits. I assume plus something else that uniquely identifies the PCI controller? -Christoffer > > > 4.71 KVM_CREATE_PIT2 > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 4b60056..2a23705 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -965,12 +965,14 @@ struct kvm_one_reg { > __u64 addr; > }; > > +#define KVM_MSI_VALID_DEVID (1U << 0) > struct kvm_msi { > __u32 address_lo; > __u32 address_hi; > __u32 data; > __u32 flags; > - __u8 pad[16]; > + __u32 devid; > + __u8 pad[12]; > }; > > struct kvm_arm_device_addr { > -- > 2.3.5 > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Christoffer, thanks for your time to reviewing this! Was probably no pleasure ;-) On 28/06/15 20:12, Christoffer Dall wrote: > On Fri, May 29, 2015 at 10:53:18AM +0100, Andre Przywara wrote: >> The ARM GICv3 ITS MSI controller requires a device ID to be able to >> assign the proper interrupt vector. On real hardware, this ID is >> sampled from the bus. To be able to emulate an ITS controller, extend >> the KVM MSI interface to let userspace provide such a device ID. For >> PCI devices, the device ID is simply the 16-bit bus-device-function >> triplet, which should be easily available to the userland tool. >> >> Signed-off-by: Andre Przywara <andre.przywara@arm.com> >> --- >> Documentation/virtual/kvm/api.txt | 8 ++++++-- >> include/uapi/linux/kvm.h | 4 +++- >> 2 files changed, 9 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt >> index 9fa2bf8..891d64a 100644 >> --- a/Documentation/virtual/kvm/api.txt >> +++ b/Documentation/virtual/kvm/api.txt >> @@ -2121,10 +2121,14 @@ struct kvm_msi { >> __u32 address_hi; >> __u32 data; >> __u32 flags; >> - __u8 pad[16]; >> + __u32 devid; >> + __u8 pad[12]; >> }; >> >> -No flags are defined so far. The corresponding field must be 0. >> +flags: KVM_MSI_VALID_DEVID: devid is valid, otherwise ignored. > > I don't see what the 'otherwise ignored' part of the sentence here is > meant to say, that the flags field is otherwise ignored for other value? No, that the devid field is ignored if this bit isn't set. I can rephrase this to be more explicit. > That's not what the current API doc specifies, it specifies that the > remainder of the field must be 0. > >> +devid: If KVM_MSI_VALID_DEVID is set, contains a value to identify the device >> + that wrote the MSI message. For PCI, this is usually a BFD >> + identifier in the lower 16 bits. > > I assume plus something else that uniquely identifies the PCI > controller? Well yes, the device ID is a unique device identifier within a system, the BFD use case was just to illustrate this and give a hint to userspace what to fill in there. I will explain this better in v2. So are you OK with that extension of the API in general? Just asking because there is a lot that depends on it. Cheers, Andre. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jun 29, 2015 at 03:53:12PM +0100, Andre Przywara wrote: > Hi Christoffer, > > thanks for your time to reviewing this! Was probably no pleasure ;-) > > On 28/06/15 20:12, Christoffer Dall wrote: > > On Fri, May 29, 2015 at 10:53:18AM +0100, Andre Przywara wrote: > >> The ARM GICv3 ITS MSI controller requires a device ID to be able to > >> assign the proper interrupt vector. On real hardware, this ID is > >> sampled from the bus. To be able to emulate an ITS controller, extend > >> the KVM MSI interface to let userspace provide such a device ID. For > >> PCI devices, the device ID is simply the 16-bit bus-device-function > >> triplet, which should be easily available to the userland tool. > >> > >> Signed-off-by: Andre Przywara <andre.przywara@arm.com> > >> --- > >> Documentation/virtual/kvm/api.txt | 8 ++++++-- > >> include/uapi/linux/kvm.h | 4 +++- > >> 2 files changed, 9 insertions(+), 3 deletions(-) > >> > >> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > >> index 9fa2bf8..891d64a 100644 > >> --- a/Documentation/virtual/kvm/api.txt > >> +++ b/Documentation/virtual/kvm/api.txt > >> @@ -2121,10 +2121,14 @@ struct kvm_msi { > >> __u32 address_hi; > >> __u32 data; > >> __u32 flags; > >> - __u8 pad[16]; > >> + __u32 devid; > >> + __u8 pad[12]; > >> }; > >> > >> -No flags are defined so far. The corresponding field must be 0. > >> +flags: KVM_MSI_VALID_DEVID: devid is valid, otherwise ignored. > > > > I don't see what the 'otherwise ignored' part of the sentence here is > > meant to say, that the flags field is otherwise ignored for other value? > > No, that the devid field is ignored if this bit isn't set. I can > rephrase this to be more explicit. > > > That's not what the current API doc specifies, it specifies that the > > remainder of the field must be 0. > > > >> +devid: If KVM_MSI_VALID_DEVID is set, contains a value to identify the device > >> + that wrote the MSI message. For PCI, this is usually a BFD > >> + identifier in the lower 16 bits. > > > > I assume plus something else that uniquely identifies the PCI > > controller? > > Well yes, the device ID is a unique device identifier within a system, > the BFD use case was just to illustrate this and give a hint to > userspace what to fill in there. I will explain this better in v2. > > So are you OK with that extension of the API in general? Just asking > because there is a lot that depends on it. > Yeah, I didn't review the series in detail yet, but the API change looks ok to me. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 9fa2bf8..891d64a 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2121,10 +2121,14 @@ struct kvm_msi { __u32 address_hi; __u32 data; __u32 flags; - __u8 pad[16]; + __u32 devid; + __u8 pad[12]; }; -No flags are defined so far. The corresponding field must be 0. +flags: KVM_MSI_VALID_DEVID: devid is valid, otherwise ignored. +devid: If KVM_MSI_VALID_DEVID is set, contains a value to identify the device + that wrote the MSI message. For PCI, this is usually a BFD + identifier in the lower 16 bits. 4.71 KVM_CREATE_PIT2 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4b60056..2a23705 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -965,12 +965,14 @@ struct kvm_one_reg { __u64 addr; }; +#define KVM_MSI_VALID_DEVID (1U << 0) struct kvm_msi { __u32 address_lo; __u32 address_hi; __u32 data; __u32 flags; - __u8 pad[16]; + __u32 devid; + __u8 pad[12]; }; struct kvm_arm_device_addr {
The ARM GICv3 ITS MSI controller requires a device ID to be able to assign the proper interrupt vector. On real hardware, this ID is sampled from the bus. To be able to emulate an ITS controller, extend the KVM MSI interface to let userspace provide such a device ID. For PCI devices, the device ID is simply the 16-bit bus-device-function triplet, which should be easily available to the userland tool. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- Documentation/virtual/kvm/api.txt | 8 ++++++-- include/uapi/linux/kvm.h | 4 +++- 2 files changed, 9 insertions(+), 3 deletions(-)