* [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD
@ 2023-02-21 3:41 Yi Liu
2023-02-21 4:39 ` Alex Williamson
0 siblings, 1 reply; 4+ messages in thread
From: Yi Liu @ 2023-02-21 3:41 UTC (permalink / raw)
To: alex.williamson, jgg, kevin.tian
Cc: cohuck, eric.auger, nicolinc, kvm, mjrosato, chao.p.peng,
yi.l.liu, yi.y.sun, pbonzini
as some vfio_device's open_device op requires kvm pointer and kvm pointer
set is part of GROUP_ADD.
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
Documentation/virt/kvm/devices/vfio.rst | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst
index 2d20dc561069..5722e283f1b5 100644
--- a/Documentation/virt/kvm/devices/vfio.rst
+++ b/Documentation/virt/kvm/devices/vfio.rst
@@ -39,3 +39,8 @@ KVM_DEV_VFIO_GROUP attributes:
- @groupfd is a file descriptor for a VFIO group;
- @tablefd is a file descriptor for a TCE table allocated via
KVM_CREATE_SPAPR_TCE.
+
+::
+
+The GROUP_ADD operation above should be invoked before vfio_device's
+open_device op which is called in the ioctl VFIO_GROUP_GET_DEVICE_FD.
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD
2023-02-21 3:41 [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD Yi Liu
@ 2023-02-21 4:39 ` Alex Williamson
2023-02-21 5:07 ` Liu, Yi L
0 siblings, 1 reply; 4+ messages in thread
From: Alex Williamson @ 2023-02-21 4:39 UTC (permalink / raw)
To: Yi Liu
Cc: jgg, kevin.tian, cohuck, eric.auger, nicolinc, kvm, mjrosato,
chao.p.peng, yi.y.sun, pbonzini
On Mon, 20 Feb 2023 19:41:14 -0800
Yi Liu <yi.l.liu@intel.com> wrote:
> as some vfio_device's open_device op requires kvm pointer and kvm pointer
> set is part of GROUP_ADD.
>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
> Documentation/virt/kvm/devices/vfio.rst | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst
> index 2d20dc561069..5722e283f1b5 100644
> --- a/Documentation/virt/kvm/devices/vfio.rst
> +++ b/Documentation/virt/kvm/devices/vfio.rst
> @@ -39,3 +39,8 @@ KVM_DEV_VFIO_GROUP attributes:
> - @groupfd is a file descriptor for a VFIO group;
> - @tablefd is a file descriptor for a TCE table allocated via
> KVM_CREATE_SPAPR_TCE.
> +
> +::
> +
> +The GROUP_ADD operation above should be invoked before vfio_device's
> +open_device op which is called in the ioctl VFIO_GROUP_GET_DEVICE_FD.
Why only include the reasoning in the commit log and not the docs?
Thanks,
Alex
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD
2023-02-21 4:39 ` Alex Williamson
@ 2023-02-21 5:07 ` Liu, Yi L
2023-02-21 18:03 ` Alex Williamson
0 siblings, 1 reply; 4+ messages in thread
From: Liu, Yi L @ 2023-02-21 5:07 UTC (permalink / raw)
To: Alex Williamson
Cc: jgg, Tian, Kevin, cohuck, eric.auger, nicolinc, kvm, mjrosato,
chao.p.peng, yi.y.sun, pbonzini
> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Tuesday, February 21, 2023 12:39 PM
>
> On Mon, 20 Feb 2023 19:41:14 -0800
> Yi Liu <yi.l.liu@intel.com> wrote:
>
> > as some vfio_device's open_device op requires kvm pointer and kvm
> pointer
> > set is part of GROUP_ADD.
> >
> > Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> > ---
> > Documentation/virt/kvm/devices/vfio.rst | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/Documentation/virt/kvm/devices/vfio.rst
> b/Documentation/virt/kvm/devices/vfio.rst
> > index 2d20dc561069..5722e283f1b5 100644
> > --- a/Documentation/virt/kvm/devices/vfio.rst
> > +++ b/Documentation/virt/kvm/devices/vfio.rst
> > @@ -39,3 +39,8 @@ KVM_DEV_VFIO_GROUP attributes:
> > - @groupfd is a file descriptor for a VFIO group;
> > - @tablefd is a file descriptor for a TCE table allocated via
> > KVM_CREATE_SPAPR_TCE.
> > +
> > +::
> > +
> > +The GROUP_ADD operation above should be invoked before
> vfio_device's
> > +open_device op which is called in the ioctl
> VFIO_GROUP_GET_DEVICE_FD.
>
> Why only include the reasoning in the commit log and not the docs?
Oops, sure. How about below?
KVM_DEV_VFIO_GROUP_ADD has a duty to set the kvm pointer to VFIO as some
vfio_devices require kvm pointer to open_device. Like gvt-g, vfio-ap and etc.
Meanwhile, open_device is part of VFIO_GROUP_GET_DEVICE_FD. Hence user should
invoke KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD.
Regards,
Yi Liu
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD
2023-02-21 5:07 ` Liu, Yi L
@ 2023-02-21 18:03 ` Alex Williamson
0 siblings, 0 replies; 4+ messages in thread
From: Alex Williamson @ 2023-02-21 18:03 UTC (permalink / raw)
To: Liu, Yi L
Cc: jgg, Tian, Kevin, cohuck, eric.auger, nicolinc, kvm, mjrosato,
chao.p.peng, yi.y.sun, pbonzini
On Tue, 21 Feb 2023 05:07:36 +0000
"Liu, Yi L" <yi.l.liu@intel.com> wrote:
> > From: Alex Williamson <alex.williamson@redhat.com>
> > Sent: Tuesday, February 21, 2023 12:39 PM
> >
> > On Mon, 20 Feb 2023 19:41:14 -0800
> > Yi Liu <yi.l.liu@intel.com> wrote:
> >
> > > as some vfio_device's open_device op requires kvm pointer and kvm
> > pointer
> > > set is part of GROUP_ADD.
> > >
> > > Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> > > ---
> > > Documentation/virt/kvm/devices/vfio.rst | 5 +++++
> > > 1 file changed, 5 insertions(+)
> > >
> > > diff --git a/Documentation/virt/kvm/devices/vfio.rst
> > b/Documentation/virt/kvm/devices/vfio.rst
> > > index 2d20dc561069..5722e283f1b5 100644
> > > --- a/Documentation/virt/kvm/devices/vfio.rst
> > > +++ b/Documentation/virt/kvm/devices/vfio.rst
> > > @@ -39,3 +39,8 @@ KVM_DEV_VFIO_GROUP attributes:
> > > - @groupfd is a file descriptor for a VFIO group;
> > > - @tablefd is a file descriptor for a TCE table allocated via
> > > KVM_CREATE_SPAPR_TCE.
> > > +
> > > +::
> > > +
> > > +The GROUP_ADD operation above should be invoked before
> > vfio_device's
> > > +open_device op which is called in the ioctl
> > VFIO_GROUP_GET_DEVICE_FD.
> >
> > Why only include the reasoning in the commit log and not the docs?
>
> Oops, sure. How about below?
>
> KVM_DEV_VFIO_GROUP_ADD has a duty to set the kvm pointer to VFIO as some
> vfio_devices require kvm pointer to open_device. Like gvt-g, vfio-ap and etc.
> Meanwhile, open_device is part of VFIO_GROUP_GET_DEVICE_FD. Hence user should
> invoke KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD.
How about:
The GROUP_ADD operation above should be invoked prior to accessing the
device file descriptor via VFIO_GROUP_GET_DEVICE_FD in order to support
drivers which require a kvm pointer to be set in their .open_device()
callback.
Thanks,
Alex
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-02-21 18:03 UTC | newest]
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2023-02-21 3:41 [PATCH] docs: kvm: vfio: Require call KVM_DEV_VFIO_GROUP_ADD before VFIO_GROUP_GET_DEVICE_FD Yi Liu
2023-02-21 4:39 ` Alex Williamson
2023-02-21 5:07 ` Liu, Yi L
2023-02-21 18:03 ` Alex Williamson
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