[virtio-dev] [PATCH v3] content: document SR-IOV driver requirements

[virtio-dev] [PATCH v3] content: document SR-IOV driver requirements

[Tiwei Bie]

Document the driver requirements for the VIRTIO_F_SR_IOV
feature bit.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Fixes: https://github.com/oasis-tcs/virtio-spec/issues/13
---
v2:
- Fix the commit message (MST);
- Improve the wording (MST);
- Drop unnecessary parts (MST);

v3:
- status -> device status (MST);

 content.tex | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/content.tex b/content.tex
index be18234..ab18210 100644
--- a/content.tex
+++ b/content.tex
@@ -5387,6 +5387,21 @@ A driver SHOULD accept VIRTIO_F_IO_BARRIER if it is offered.
 If VIRTIO_F_IO_BARRIER has been negotiated, a driver MUST use
 the barriers suitable for hardware devices.
 
+If VIRTIO_F_SR_IOV has been negotiated, a driver MAY enable
+virtual functions through the device's PCI SR-IOV capability
+structure.  A driver MUST NOT negotiate VIRTIO_F_SR_IOV if
+the device does not have a PCI SR-IOV capability structure
+or is not a PCI device.  A driver MUST negotiate
+VIRTIO_F_SR_IOV and complete the feature negotiation
+(including checking the FEATURES_OK \field{device status}
+bit) before enabling virtual functions through the device's
+PCI SR-IOV capability structure.  After once successfully
+negotiating VIRTIO_F_SR_IOV, the driver MAY enable virtual
+functions through the device's PCI SR-IOV capability
+structure even if the device or the system has been fully
+or partially reset, and even without re-negotiating
+VIRTIO_F_SR_IOV after the reset.
+
 \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits}
 
 A device MUST offer VIRTIO_F_VERSION_1.  A device MAY fail to operate further
-- 
2.17.0


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[virtio-dev] Re: [PATCH v3] content: document SR-IOV driver requirements

[Cornelia Huck]

On Tue, 12 Jun 2018 13:18:00 +0800
Tiwei Bie <tiwei.bie@intel.com> wrote:

> Document the driver requirements for the VIRTIO_F_SR_IOV
> feature bit.
> 
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> Fixes: https://github.com/oasis-tcs/virtio-spec/issues/13
> ---
> v2:
> - Fix the commit message (MST);
> - Improve the wording (MST);
> - Drop unnecessary parts (MST);
> 
> v3:
> - status -> device status (MST);
> 
>  content.tex | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/content.tex b/content.tex
> index be18234..ab18210 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -5387,6 +5387,21 @@ A driver SHOULD accept VIRTIO_F_IO_BARRIER if it is offered.
>  If VIRTIO_F_IO_BARRIER has been negotiated, a driver MUST use
>  the barriers suitable for hardware devices.
>  
> +If VIRTIO_F_SR_IOV has been negotiated, a driver MAY enable
> +virtual functions through the device's PCI SR-IOV capability
> +structure.  A driver MUST NOT negotiate VIRTIO_F_SR_IOV if
> +the device does not have a PCI SR-IOV capability structure
> +or is not a PCI device.  A driver MUST negotiate
> +VIRTIO_F_SR_IOV and complete the feature negotiation
> +(including checking the FEATURES_OK \field{device status}
> +bit) before enabling virtual functions through the device's
> +PCI SR-IOV capability structure.  After once successfully
> +negotiating VIRTIO_F_SR_IOV, the driver MAY enable virtual
> +functions through the device's PCI SR-IOV capability
> +structure even if the device or the system has been fully
> +or partially reset, and even without re-negotiating
> +VIRTIO_F_SR_IOV after the reset.
> +
>  \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits}
>  
>  A device MUST offer VIRTIO_F_VERSION_1.  A device MAY fail to operate further

I still think we should mention somewhere that this "enable just once"
mechanism is useful for e.g. resuming; but this is fine as-is.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

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Re: [virtio-dev] [PATCH v3] content: document SR-IOV driver requirements

[Tiwei Bie]

On Tue, Jun 12, 2018 at 01:18:00PM +0800, Tiwei Bie wrote:
> Document the driver requirements for the VIRTIO_F_SR_IOV
> feature bit.
> 
> Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> Fixes: https://github.com/oasis-tcs/virtio-spec/issues/13
> ---
> v2:
> - Fix the commit message (MST);
> - Improve the wording (MST);
> - Drop unnecessary parts (MST);
> 
> v3:
> - status -> device status (MST);
> 
>  content.tex | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)

Please start the voting on this proposal. Thanks!

Best regards,
Tiwei Bie

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Re: [virtio-dev] [PATCH v3] content: document SR-IOV driver requirements

[Michael S. Tsirkin]

On Thu, Oct 25, 2018 at 09:46:44AM +0800, Tiwei Bie wrote:
> On Tue, Jun 12, 2018 at 01:18:00PM +0800, Tiwei Bie wrote:
> > Document the driver requirements for the VIRTIO_F_SR_IOV
> > feature bit.
> > 
> > Suggested-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/13
> > ---
> > v2:
> > - Fix the commit message (MST);
> > - Improve the wording (MST);
> > - Drop unnecessary parts (MST);
> > 
> > v3:
> > - status -> device status (MST);
> > 
> >  content.tex | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> 
> Please start the voting on this proposal. Thanks!
> 
> Best regards,
> Tiwei Bie

Sure. Given conferences I think we'll do a 3 week voting period.


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