* [virtio-dev] [PATCH v3] content: support SR-IOV @ 2018-05-22 10:26 Tiwei Bie 2018-05-22 11:03 ` [virtio-dev] " Cornelia Huck 2018-05-23 17:54 ` [virtio-dev] " Michael S. Tsirkin 0 siblings, 2 replies; 9+ messages in thread From: Tiwei Bie @ 2018-05-22 10:26 UTC (permalink / raw) To: mst, cohuck, stefanha, pbonzini, virtio-dev Cc: dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang Allocate a feature bit for virtio devices which support SR-IOV. 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/11 --- More details can be found from this thread: https://patchwork.kernel.org/patch/10285541/ This patch needs below patch applied first: https://github.com/oasis-tcs/virtio-spec/issues/10 https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html v2 -> v3: - Improve the wording (Cornelia); v1 -> v2: - s/Reserve/Allocate/ (MST); - Add a Fixes tag (MST); - Be more explicit in driver requirement (MST); - Remove the "device MAY fail" description (MST); - Rebase on IO_BARRIER patch; RFC -> v1: - Mention PCI in the description (Cornelia); content.tex | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/content.tex b/content.tex index 95c243f..e9e6f9a 100644 --- a/content.tex +++ b/content.tex @@ -95,10 +95,10 @@ Feature bits are allocated as follows: \begin{description} \item[0 to 23] Feature bits for the specific device type -\item[24 to 36] Feature bits reserved for extensions to the queue and +\item[24 to 37] Feature bits reserved for extensions to the queue and feature negotiation mechanisms -\item[37 and above] Feature bits reserved for future extensions. +\item[38 and above] Feature bits reserved for future extensions. \end{description} \begin{note} @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp better performance. This feature indicates whether a stronger form of barrier suitable for hardware devices is necessary. + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that + the device supports Single Root I/O Virtualization. + Currently only PCI devices support this feature. \end{description} \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} @@ -5376,6 +5379,11 @@ 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. +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. +If VIRTIO_F_SR_IOV has been negotiated, a driver can +enable virtual functions through the device's PCI SR-IOV +capability structure. + \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. A device MAY fail to operate further if VIRTIO_F_IO_BARRIER is not accepted. +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI +SR-IOV capability structure. + \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} Transitional devices MAY offer the following: -- 2.17.0 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [virtio-dev] Re: [PATCH v3] content: support SR-IOV 2018-05-22 10:26 [virtio-dev] [PATCH v3] content: support SR-IOV Tiwei Bie @ 2018-05-22 11:03 ` Cornelia Huck 2018-05-23 17:54 ` [virtio-dev] " Michael S. Tsirkin 1 sibling, 0 replies; 9+ messages in thread From: Cornelia Huck @ 2018-05-22 11:03 UTC (permalink / raw) To: Tiwei Bie Cc: mst, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Tue, 22 May 2018 18:26:15 +0800 Tiwei Bie <tiwei.bie@intel.com> wrote: > Allocate a feature bit for virtio devices which support SR-IOV. > > 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/11 Reviewed-by: Cornelia Huck <cohuck@redhat.com> --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-22 10:26 [virtio-dev] [PATCH v3] content: support SR-IOV Tiwei Bie 2018-05-22 11:03 ` [virtio-dev] " Cornelia Huck @ 2018-05-23 17:54 ` Michael S. Tsirkin 2018-05-23 19:34 ` Michael S. Tsirkin 1 sibling, 1 reply; 9+ messages in thread From: Michael S. Tsirkin @ 2018-05-23 17:54 UTC (permalink / raw) To: Tiwei Bie Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > Allocate a feature bit for virtio devices which support SR-IOV. > > 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/11 > --- > More details can be found from this thread: > https://patchwork.kernel.org/patch/10285541/ > > This patch needs below patch applied first: > https://github.com/oasis-tcs/virtio-spec/issues/10 > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > v2 -> v3: > - Improve the wording (Cornelia); > > v1 -> v2: > - s/Reserve/Allocate/ (MST); > - Add a Fixes tag (MST); > - Be more explicit in driver requirement (MST); > - Remove the "device MAY fail" description (MST); > - Rebase on IO_BARRIER patch; > > RFC -> v1: > - Mention PCI in the description (Cornelia); > > content.tex | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) > > diff --git a/content.tex b/content.tex > index 95c243f..e9e6f9a 100644 > --- a/content.tex > +++ b/content.tex > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > \begin{description} > \item[0 to 23] Feature bits for the specific device type > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > +\item[24 to 37] Feature bits reserved for extensions to the queue and > feature negotiation mechanisms > > -\item[37 and above] Feature bits reserved for future extensions. > +\item[38 and above] Feature bits reserved for future extensions. > \end{description} > > \begin{note} > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > better performance. This feature indicates whether > a stronger form of barrier suitable for hardware > devices is necessary. > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > + the device supports Single Root I/O Virtualization. > + Currently only PCI devices support this feature. I guess the assumption is that all VFs and the PF are of the same type? I feel it might be handy down the road to support mixing types. For this reason, to avoid binding a wrong driver to a VF, I propose that all VFs have this bit too, and require that drivers ignore VFs without this bit. What do you think? > \end{description} > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > @@ -5376,6 +5379,11 @@ 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. > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > +enable virtual functions through the device's PCI SR-IOV > +capability structure. I feel the last sentence isn't clear enough. How about a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature negotiation (including setting the DRIVER_OK \field{status} bit) before enabling virtual functions through the device's PCI SR-IOV capability structure. > + > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > is not accepted. > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > +SR-IOV capability structure. > + > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > Transitional devices MAY offer the following: > -- > 2.17.0 > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-23 17:54 ` [virtio-dev] " Michael S. Tsirkin @ 2018-05-23 19:34 ` Michael S. Tsirkin 2018-05-24 0:06 ` Tiwei Bie 0 siblings, 1 reply; 9+ messages in thread From: Michael S. Tsirkin @ 2018-05-23 19:34 UTC (permalink / raw) To: Tiwei Bie Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > > Allocate a feature bit for virtio devices which support SR-IOV. > > > > 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/11 > > --- > > More details can be found from this thread: > > https://patchwork.kernel.org/patch/10285541/ > > > > This patch needs below patch applied first: > > https://github.com/oasis-tcs/virtio-spec/issues/10 > > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > > > v2 -> v3: > > - Improve the wording (Cornelia); > > > > v1 -> v2: > > - s/Reserve/Allocate/ (MST); > > - Add a Fixes tag (MST); > > - Be more explicit in driver requirement (MST); > > - Remove the "device MAY fail" description (MST); > > - Rebase on IO_BARRIER patch; > > > > RFC -> v1: > > - Mention PCI in the description (Cornelia); > > > > content.tex | 15 +++++++++++++-- > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > diff --git a/content.tex b/content.tex > > index 95c243f..e9e6f9a 100644 > > --- a/content.tex > > +++ b/content.tex > > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > > \begin{description} > > \item[0 to 23] Feature bits for the specific device type > > > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > > +\item[24 to 37] Feature bits reserved for extensions to the queue and > > feature negotiation mechanisms > > > > -\item[37 and above] Feature bits reserved for future extensions. > > +\item[38 and above] Feature bits reserved for future extensions. > > \end{description} > > > > \begin{note} > > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > > better performance. This feature indicates whether > > a stronger form of barrier suitable for hardware > > devices is necessary. > > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > > + the device supports Single Root I/O Virtualization. > > + Currently only PCI devices support this feature. > > I guess the assumption is that all VFs and the PF are of the same type? > > I feel it might be handy down the road to support mixing > types. For this reason, to avoid binding a wrong driver > to a VF, I propose that all VFs have this bit too, > and require that drivers ignore VFs without this bit. > > What do you think? Thinking more about it, I can see how this might interfere with passing VFs through to legacy nested guests. How about reversing it then? Require that drivers MUST NOT negotiate VIRTIO_F_SR_IOV if device does not have an SRIOV capability or is not a PCI device, in particular a VF. And say a device without SRIOV cap SHOULD NOT expose this bit. > > \end{description} > > > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > @@ -5376,6 +5379,11 @@ 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. > > > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > > +enable virtual functions through the device's PCI SR-IOV > > +capability structure. > > I feel the last sentence isn't clear enough. How about > > a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature > negotiation (including setting the DRIVER_OK \field{status} bit) before > enabling virtual functions through the device's PCI SR-IOV capability > structure. > > > + > > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > > is not accepted. > > > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > > +SR-IOV capability structure. > > + > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > > > Transitional devices MAY offer the following: > > > > > -- > > 2.17.0 > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-23 19:34 ` Michael S. Tsirkin @ 2018-05-24 0:06 ` Tiwei Bie 2018-05-24 13:44 ` Michael S. Tsirkin 0 siblings, 1 reply; 9+ messages in thread From: Tiwei Bie @ 2018-05-24 0:06 UTC (permalink / raw) To: Michael S. Tsirkin Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Wed, May 23, 2018 at 10:34:29PM +0300, Michael S. Tsirkin wrote: > On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > > > Allocate a feature bit for virtio devices which support SR-IOV. > > > > > > 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/11 > > > --- > > > More details can be found from this thread: > > > https://patchwork.kernel.org/patch/10285541/ > > > > > > This patch needs below patch applied first: > > > https://github.com/oasis-tcs/virtio-spec/issues/10 > > > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > > > > > v2 -> v3: > > > - Improve the wording (Cornelia); > > > > > > v1 -> v2: > > > - s/Reserve/Allocate/ (MST); > > > - Add a Fixes tag (MST); > > > - Be more explicit in driver requirement (MST); > > > - Remove the "device MAY fail" description (MST); > > > - Rebase on IO_BARRIER patch; > > > > > > RFC -> v1: > > > - Mention PCI in the description (Cornelia); > > > > > > content.tex | 15 +++++++++++++-- > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > diff --git a/content.tex b/content.tex > > > index 95c243f..e9e6f9a 100644 > > > --- a/content.tex > > > +++ b/content.tex > > > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > > > \begin{description} > > > \item[0 to 23] Feature bits for the specific device type > > > > > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > > > +\item[24 to 37] Feature bits reserved for extensions to the queue and > > > feature negotiation mechanisms > > > > > > -\item[37 and above] Feature bits reserved for future extensions. > > > +\item[38 and above] Feature bits reserved for future extensions. > > > \end{description} > > > > > > \begin{note} > > > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > > > better performance. This feature indicates whether > > > a stronger form of barrier suitable for hardware > > > devices is necessary. > > > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > > > + the device supports Single Root I/O Virtualization. > > > + Currently only PCI devices support this feature. > > > > I guess the assumption is that all VFs and the PF are of the same type? > > > > I feel it might be handy down the road to support mixing > > types. For this reason, to avoid binding a wrong driver > > to a VF, I propose that all VFs have this bit too, > > and require that drivers ignore VFs without this bit. > > > > What do you think? > > Thinking more about it, I can see how this might > interfere with passing VFs through to legacy nested guests. > How about reversing it then? > > Require that drivers MUST NOT negotiate VIRTIO_F_SR_IOV > if device does not have an SRIOV capability or > is not a PCI device, in particular a VF. I think driver can accept this feature as long as it's able to handle the SR-IOV capability and there is no need for it to check whether the device has the SR-IOV capability. And device should make sure that it won't offer this feature if it doesn't present this capability. How about changing the driver requirement to: A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. If VIRTIO_F_SR_IOV has been negotiated, a driver can enable virtual functions through the device's PCI SR-IOV capability structure. A driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature negotiation (including setting the DRIVER_OK \field{status} bit) before enabling virtual functions through the device's PCI SR-IOV capability structure. > > And say a device without SRIOV cap SHOULD NOT expose this bit. > No problem. How about: A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI SR-IOV capability structure. A device SHOULD NOT offer VIRTIO_F_SR_IOV if it doesn't presents a PCI SR-IOV capability structure. > > > > > \end{description} > > > > > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > @@ -5376,6 +5379,11 @@ 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. > > > > > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > > > +enable virtual functions through the device's PCI SR-IOV > > > +capability structure. > > > > I feel the last sentence isn't clear enough. How about > > > > a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature > > negotiation (including setting the DRIVER_OK \field{status} bit) before > > enabling virtual functions through the device's PCI SR-IOV capability > > structure. > > > > > + > > > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > > > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > > > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > > > is not accepted. > > > > > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > > > +SR-IOV capability structure. > > > + > > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > > > > > Transitional devices MAY offer the following: > > > > > > > > > -- > > > 2.17.0 > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-24 0:06 ` Tiwei Bie @ 2018-05-24 13:44 ` Michael S. Tsirkin 2018-05-24 15:15 ` Tiwei Bie 0 siblings, 1 reply; 9+ messages in thread From: Michael S. Tsirkin @ 2018-05-24 13:44 UTC (permalink / raw) To: Tiwei Bie Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Thu, May 24, 2018 at 08:06:41AM +0800, Tiwei Bie wrote: > On Wed, May 23, 2018 at 10:34:29PM +0300, Michael S. Tsirkin wrote: > > On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > > > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > > > > Allocate a feature bit for virtio devices which support SR-IOV. > > > > > > > > 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/11 > > > > --- > > > > More details can be found from this thread: > > > > https://patchwork.kernel.org/patch/10285541/ > > > > > > > > This patch needs below patch applied first: > > > > https://github.com/oasis-tcs/virtio-spec/issues/10 > > > > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > > > > > > > v2 -> v3: > > > > - Improve the wording (Cornelia); > > > > > > > > v1 -> v2: > > > > - s/Reserve/Allocate/ (MST); > > > > - Add a Fixes tag (MST); > > > > - Be more explicit in driver requirement (MST); > > > > - Remove the "device MAY fail" description (MST); > > > > - Rebase on IO_BARRIER patch; > > > > > > > > RFC -> v1: > > > > - Mention PCI in the description (Cornelia); > > > > > > > > content.tex | 15 +++++++++++++-- > > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/content.tex b/content.tex > > > > index 95c243f..e9e6f9a 100644 > > > > --- a/content.tex > > > > +++ b/content.tex > > > > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > > > > \begin{description} > > > > \item[0 to 23] Feature bits for the specific device type > > > > > > > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > > > > +\item[24 to 37] Feature bits reserved for extensions to the queue and > > > > feature negotiation mechanisms > > > > > > > > -\item[37 and above] Feature bits reserved for future extensions. > > > > +\item[38 and above] Feature bits reserved for future extensions. > > > > \end{description} > > > > > > > > \begin{note} > > > > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > > > > better performance. This feature indicates whether > > > > a stronger form of barrier suitable for hardware > > > > devices is necessary. > > > > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > > > > + the device supports Single Root I/O Virtualization. > > > > + Currently only PCI devices support this feature. > > > > > > I guess the assumption is that all VFs and the PF are of the same type? > > > > > > I feel it might be handy down the road to support mixing > > > types. For this reason, to avoid binding a wrong driver > > > to a VF, I propose that all VFs have this bit too, > > > and require that drivers ignore VFs without this bit. > > > > > > What do you think? > > > > Thinking more about it, I can see how this might > > interfere with passing VFs through to legacy nested guests. > > How about reversing it then? > > > > Require that drivers MUST NOT negotiate VIRTIO_F_SR_IOV > > if device does not have an SRIOV capability or > > is not a PCI device, in particular a VF. > > I think driver can accept this feature as long as it's > able to handle the SR-IOV capability and there is no > need for it to check whether the device has the SR-IOV > capability. So my point is this, VFs themselves do not have this feature. Should all of them have it? None of them? I don't see what use it is to VFs, but maybe we will come with a use down the road. I propose we require that 1. drivers ignore this if there is no SRIOV cap, and 2. that devices do not expose it. This way if we come up with a use down the road, only new drivers will negotiate it. > And device should make sure that it won't > offer this feature if it doesn't present this capability. > How about changing the driver requirement to: > > A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. This part won't address the issue above. > If VIRTIO_F_SR_IOV has been negotiated, a driver can > enable virtual functions through the device's PCI SR-IOV > capability structure. A driver MUST negotiate VIRTIO_F_SR_IOV > and complete the feature negotiation (including setting > the DRIVER_OK \field{status} bit) before enabling virtual > functions through the device's PCI SR-IOV capability > structure. > > > > > > And say a device without SRIOV cap SHOULD NOT expose this bit. > > > > No problem. How about: > > A device SHOULD offer VIRTIO_F_SR_IOV if it presents a > PCI SR-IOV capability structure. A device SHOULD NOT > offer VIRTIO_F_SR_IOV if it doesn't presents doesn't present > a PCI SR-IOV > capability structure. Assuming we teach drivers they should ignore it if it is there without SRIOV, then this last one I'd make MUST NOT. > > > > > > > > \end{description} > > > > > > > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > @@ -5376,6 +5379,11 @@ 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. > > > > > > > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > > > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > > > > +enable virtual functions through the device's PCI SR-IOV > > > > +capability structure. > > > > > > I feel the last sentence isn't clear enough. How about > > > > > > a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature > > > negotiation (including setting the DRIVER_OK \field{status} bit) before > > > enabling virtual functions through the device's PCI SR-IOV capability > > > structure. > > > > > > > + > > > > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > > > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > > > > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > > > > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > > > > is not accepted. > > > > > > > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > > > > +SR-IOV capability structure. > > > > + > > > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > > > > > > > Transitional devices MAY offer the following: > > > > > > > > > > > > > -- > > > > 2.17.0 > > > > > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-24 13:44 ` Michael S. Tsirkin @ 2018-05-24 15:15 ` Tiwei Bie 2018-05-24 15:20 ` Michael S. Tsirkin 0 siblings, 1 reply; 9+ messages in thread From: Tiwei Bie @ 2018-05-24 15:15 UTC (permalink / raw) To: Michael S. Tsirkin Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Thu, May 24, 2018 at 04:44:18PM +0300, Michael S. Tsirkin wrote: > On Thu, May 24, 2018 at 08:06:41AM +0800, Tiwei Bie wrote: > > On Wed, May 23, 2018 at 10:34:29PM +0300, Michael S. Tsirkin wrote: > > > On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > > > > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > > > > > Allocate a feature bit for virtio devices which support SR-IOV. > > > > > > > > > > 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/11 > > > > > --- > > > > > More details can be found from this thread: > > > > > https://patchwork.kernel.org/patch/10285541/ > > > > > > > > > > This patch needs below patch applied first: > > > > > https://github.com/oasis-tcs/virtio-spec/issues/10 > > > > > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > > > > > > > > > v2 -> v3: > > > > > - Improve the wording (Cornelia); > > > > > > > > > > v1 -> v2: > > > > > - s/Reserve/Allocate/ (MST); > > > > > - Add a Fixes tag (MST); > > > > > - Be more explicit in driver requirement (MST); > > > > > - Remove the "device MAY fail" description (MST); > > > > > - Rebase on IO_BARRIER patch; > > > > > > > > > > RFC -> v1: > > > > > - Mention PCI in the description (Cornelia); > > > > > > > > > > content.tex | 15 +++++++++++++-- > > > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/content.tex b/content.tex > > > > > index 95c243f..e9e6f9a 100644 > > > > > --- a/content.tex > > > > > +++ b/content.tex > > > > > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > > > > > \begin{description} > > > > > \item[0 to 23] Feature bits for the specific device type > > > > > > > > > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > > > > > +\item[24 to 37] Feature bits reserved for extensions to the queue and > > > > > feature negotiation mechanisms > > > > > > > > > > -\item[37 and above] Feature bits reserved for future extensions. > > > > > +\item[38 and above] Feature bits reserved for future extensions. > > > > > \end{description} > > > > > > > > > > \begin{note} > > > > > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > > > > > better performance. This feature indicates whether > > > > > a stronger form of barrier suitable for hardware > > > > > devices is necessary. > > > > > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > > > > > + the device supports Single Root I/O Virtualization. > > > > > + Currently only PCI devices support this feature. > > > > > > > > I guess the assumption is that all VFs and the PF are of the same type? > > > > > > > > I feel it might be handy down the road to support mixing > > > > types. For this reason, to avoid binding a wrong driver > > > > to a VF, I propose that all VFs have this bit too, > > > > and require that drivers ignore VFs without this bit. > > > > > > > > What do you think? > > > > > > Thinking more about it, I can see how this might > > > interfere with passing VFs through to legacy nested guests. > > > How about reversing it then? > > > > > > Require that drivers MUST NOT negotiate VIRTIO_F_SR_IOV > > > if device does not have an SRIOV capability or > > > is not a PCI device, in particular a VF. > > > > I think driver can accept this feature as long as it's > > able to handle the SR-IOV capability and there is no > > need for it to check whether the device has the SR-IOV > > capability. > > So my point is this, VFs themselves do not have > this feature. Yeah. I also think VFs shouldn't present this feature. > > Should all of them have it? None of them? > I don't see what use it is to VFs, but maybe > we will come with a use down the road. > > I propose we require that > 1. drivers ignore this if there is > no SRIOV cap, and > > 2. that devices do not expose it. > > This way if we come up with a use down the road, only new drivers > will negotiate it. I got your point now. Thanks! How about: If VIRTIO_F_SR_IOV has been negotiated, a driver can 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 setting the DRIVER_OK \field{status} bit) before enabling virtual functions through the device's PCI SR-IOV capability structure. > > > > > And device should make sure that it won't > > offer this feature if it doesn't present this capability. > > How about changing the driver requirement to: > > > > A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > This part won't address the issue above. > > > > If VIRTIO_F_SR_IOV has been negotiated, a driver can > > enable virtual functions through the device's PCI SR-IOV > > capability structure. A driver MUST negotiate VIRTIO_F_SR_IOV > > and complete the feature negotiation (including setting > > the DRIVER_OK \field{status} bit) before enabling virtual > > functions through the device's PCI SR-IOV capability > > structure. > > > > > > > > > > And say a device without SRIOV cap SHOULD NOT expose this bit. > > > > > > > No problem. How about: > > > > A device SHOULD offer VIRTIO_F_SR_IOV if it presents a > > PCI SR-IOV capability structure. A device SHOULD NOT > > offer VIRTIO_F_SR_IOV if it doesn't presents > > doesn't present Right. Thanks for catching it! > > > a PCI SR-IOV > > capability structure. > > Assuming we teach drivers they should ignore it > if it is there without SRIOV, then this last one I'd make MUST NOT. Okay, how about A device SHOULD offer VIRTIO_F_SR_IOV if it is a PCI device and presents a PCI SR-IOV capability structure, otherwise it MUST NOT offer VIRTIO_F_SR_IOV. Best regards, Tiwei Bie > > > > > > > > > > > > \end{description} > > > > > > > > > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > @@ -5376,6 +5379,11 @@ 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. > > > > > > > > > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > > > > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > > > > > +enable virtual functions through the device's PCI SR-IOV > > > > > +capability structure. > > > > > > > > I feel the last sentence isn't clear enough. How about > > > > > > > > a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature > > > > negotiation (including setting the DRIVER_OK \field{status} bit) before > > > > enabling virtual functions through the device's PCI SR-IOV capability > > > > structure. > > > > > > > > > + > > > > > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > > > > > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > > > > > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > > > > > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > > > > > is not accepted. > > > > > > > > > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > > > > > +SR-IOV capability structure. > > > > > + > > > > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > > > > > > > > > Transitional devices MAY offer the following: > > > > > > > > > > > > > > > > > -- > > > > > 2.17.0 > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > > > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > > --------------------------------------------------------------------- > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-24 15:15 ` Tiwei Bie @ 2018-05-24 15:20 ` Michael S. Tsirkin 2018-05-24 15:27 ` Tiwei Bie 0 siblings, 1 reply; 9+ messages in thread From: Michael S. Tsirkin @ 2018-05-24 15:20 UTC (permalink / raw) To: Tiwei Bie Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Thu, May 24, 2018 at 11:15:26PM +0800, Tiwei Bie wrote: > On Thu, May 24, 2018 at 04:44:18PM +0300, Michael S. Tsirkin wrote: > > On Thu, May 24, 2018 at 08:06:41AM +0800, Tiwei Bie wrote: > > > On Wed, May 23, 2018 at 10:34:29PM +0300, Michael S. Tsirkin wrote: > > > > On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > > > > > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: > > > > > > Allocate a feature bit for virtio devices which support SR-IOV. > > > > > > > > > > > > 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/11 > > > > > > --- > > > > > > More details can be found from this thread: > > > > > > https://patchwork.kernel.org/patch/10285541/ > > > > > > > > > > > > This patch needs below patch applied first: > > > > > > https://github.com/oasis-tcs/virtio-spec/issues/10 > > > > > > https://lists.oasis-open.org/archives/virtio-dev/201805/msg00046.html > > > > > > > > > > > > v2 -> v3: > > > > > > - Improve the wording (Cornelia); > > > > > > > > > > > > v1 -> v2: > > > > > > - s/Reserve/Allocate/ (MST); > > > > > > - Add a Fixes tag (MST); > > > > > > - Be more explicit in driver requirement (MST); > > > > > > - Remove the "device MAY fail" description (MST); > > > > > > - Rebase on IO_BARRIER patch; > > > > > > > > > > > > RFC -> v1: > > > > > > - Mention PCI in the description (Cornelia); > > > > > > > > > > > > content.tex | 15 +++++++++++++-- > > > > > > 1 file changed, 13 insertions(+), 2 deletions(-) > > > > > > > > > > > > diff --git a/content.tex b/content.tex > > > > > > index 95c243f..e9e6f9a 100644 > > > > > > --- a/content.tex > > > > > > +++ b/content.tex > > > > > > @@ -95,10 +95,10 @@ Feature bits are allocated as follows: > > > > > > \begin{description} > > > > > > \item[0 to 23] Feature bits for the specific device type > > > > > > > > > > > > -\item[24 to 36] Feature bits reserved for extensions to the queue and > > > > > > +\item[24 to 37] Feature bits reserved for extensions to the queue and > > > > > > feature negotiation mechanisms > > > > > > > > > > > > -\item[37 and above] Feature bits reserved for future extensions. > > > > > > +\item[38 and above] Feature bits reserved for future extensions. > > > > > > \end{description} > > > > > > > > > > > > \begin{note} > > > > > > @@ -5357,6 +5357,9 @@ Descriptors} and \ref{sec:Packed Virtqueues / Indirect Flag: Scatter-Gather Supp > > > > > > better performance. This feature indicates whether > > > > > > a stronger form of barrier suitable for hardware > > > > > > devices is necessary. > > > > > > + \item[VIRTIO_F_SR_IOV(37)] This feature indicates that > > > > > > + the device supports Single Root I/O Virtualization. > > > > > > + Currently only PCI devices support this feature. > > > > > > > > > > I guess the assumption is that all VFs and the PF are of the same type? > > > > > > > > > > I feel it might be handy down the road to support mixing > > > > > types. For this reason, to avoid binding a wrong driver > > > > > to a VF, I propose that all VFs have this bit too, > > > > > and require that drivers ignore VFs without this bit. > > > > > > > > > > What do you think? > > > > > > > > Thinking more about it, I can see how this might > > > > interfere with passing VFs through to legacy nested guests. > > > > How about reversing it then? > > > > > > > > Require that drivers MUST NOT negotiate VIRTIO_F_SR_IOV > > > > if device does not have an SRIOV capability or > > > > is not a PCI device, in particular a VF. > > > > > > I think driver can accept this feature as long as it's > > > able to handle the SR-IOV capability and there is no > > > need for it to check whether the device has the SR-IOV > > > capability. > > > > So my point is this, VFs themselves do not have > > this feature. > > Yeah. I also think VFs shouldn't present this feature. > > > > > Should all of them have it? None of them? > > I don't see what use it is to VFs, but maybe > > we will come with a use down the road. > > > > I propose we require that > > 1. drivers ignore this if there is > > no SRIOV cap, and > > > > 2. that devices do not expose it. > > > > This way if we come up with a use down the road, only new drivers > > will negotiate it. > > I got your point now. Thanks! > > How about: > > If VIRTIO_F_SR_IOV has been negotiated, a driver can 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 setting the DRIVER_OK \field{status} bit) before > enabling virtual functions through the device's PCI SR-IOV > capability structure. Sounds good. > > > > > > > > > > And device should make sure that it won't > > > offer this feature if it doesn't present this capability. > > > How about changing the driver requirement to: > > > > > > A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > > > This part won't address the issue above. > > > > > > > If VIRTIO_F_SR_IOV has been negotiated, a driver can > > > enable virtual functions through the device's PCI SR-IOV > > > capability structure. A driver MUST negotiate VIRTIO_F_SR_IOV > > > and complete the feature negotiation (including setting > > > the DRIVER_OK \field{status} bit) before enabling virtual > > > functions through the device's PCI SR-IOV capability > > > structure. > > > > > > > > > > > > > > And say a device without SRIOV cap SHOULD NOT expose this bit. > > > > > > > > > > No problem. How about: > > > > > > A device SHOULD offer VIRTIO_F_SR_IOV if it presents a > > > PCI SR-IOV capability structure. A device SHOULD NOT > > > offer VIRTIO_F_SR_IOV if it doesn't presents > > > > doesn't present > > Right. Thanks for catching it! > > > > > > a PCI SR-IOV > > > capability structure. > > > > Assuming we teach drivers they should ignore it > > if it is there without SRIOV, then this last one I'd make MUST NOT. > > Okay, how about > > A device SHOULD offer VIRTIO_F_SR_IOV if it is a PCI > device and presents a PCI SR-IOV capability structure, > otherwise it MUST NOT offer VIRTIO_F_SR_IOV. > > Best regards, > Tiwei Bie Sounds good. > > > > > > > > > > > > > > > > \end{description} > > > > > > > > > > > > \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > > @@ -5376,6 +5379,11 @@ 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. > > > > > > > > > > > > +A driver SHOULD accept VIRTIO_F_SR_IOV if it is offered. > > > > > > +If VIRTIO_F_SR_IOV has been negotiated, a driver can > > > > > > +enable virtual functions through the device's PCI SR-IOV > > > > > > +capability structure. > > > > > > > > > > I feel the last sentence isn't clear enough. How about > > > > > > > > > > a driver MUST negotiate VIRTIO_F_SR_IOV and complete the feature > > > > > negotiation (including setting the DRIVER_OK \field{status} bit) before > > > > > enabling virtual functions through the device's PCI SR-IOV capability > > > > > structure. > > > > > > > > > > > + > > > > > > \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} > > > > > > > > > > > > A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further > > > > > > @@ -5392,6 +5400,9 @@ buffers in the same order in which they have been available. > > > > > > A device MAY fail to operate further if VIRTIO_F_IO_BARRIER > > > > > > is not accepted. > > > > > > > > > > > > +A device SHOULD offer VIRTIO_F_SR_IOV if it presents a PCI > > > > > > +SR-IOV capability structure. > > > > > > + > > > > > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > > > > > > > > > > > Transitional devices MAY offer the following: > > > > > > > > > > > > > > > > > > > > > -- > > > > > > 2.17.0 > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > > > > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org > > For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [virtio-dev] [PATCH v3] content: support SR-IOV 2018-05-24 15:20 ` Michael S. Tsirkin @ 2018-05-24 15:27 ` Tiwei Bie 0 siblings, 0 replies; 9+ messages in thread From: Tiwei Bie @ 2018-05-24 15:27 UTC (permalink / raw) To: Michael S. Tsirkin Cc: cohuck, stefanha, pbonzini, virtio-dev, dan.daly, alexander.h.duyck, mark.d.rustad, cunming.liang, zhihong.wang On Thu, May 24, 2018 at 06:20:36PM +0300, Michael S. Tsirkin wrote: > On Thu, May 24, 2018 at 11:15:26PM +0800, Tiwei Bie wrote: > > On Thu, May 24, 2018 at 04:44:18PM +0300, Michael S. Tsirkin wrote: > > > On Thu, May 24, 2018 at 08:06:41AM +0800, Tiwei Bie wrote: > > > > On Wed, May 23, 2018 at 10:34:29PM +0300, Michael S. Tsirkin wrote: > > > > > On Wed, May 23, 2018 at 08:54:47PM +0300, Michael S. Tsirkin wrote: > > > > > > On Tue, May 22, 2018 at 06:26:15PM +0800, Tiwei Bie wrote: [...] > > > > > > So my point is this, VFs themselves do not have > > > this feature. > > > > Yeah. I also think VFs shouldn't present this feature. > > > > > > > > Should all of them have it? None of them? > > > I don't see what use it is to VFs, but maybe > > > we will come with a use down the road. > > > > > > I propose we require that > > > 1. drivers ignore this if there is > > > no SRIOV cap, and > > > > > > 2. that devices do not expose it. > > > > > > This way if we come up with a use down the road, only new drivers > > > will negotiate it. > > > > I got your point now. Thanks! > > > > How about: > > > > If VIRTIO_F_SR_IOV has been negotiated, a driver can 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 setting the DRIVER_OK \field{status} bit) before > > enabling virtual functions through the device's PCI SR-IOV > > capability structure. > > Sounds good. > [...] > > > > > > Assuming we teach drivers they should ignore it > > > if it is there without SRIOV, then this last one I'd make MUST NOT. > > > > Okay, how about > > > > A device SHOULD offer VIRTIO_F_SR_IOV if it is a PCI > > device and presents a PCI SR-IOV capability structure, > > otherwise it MUST NOT offer VIRTIO_F_SR_IOV. > > > > Best regards, > > Tiwei Bie > > Sounds good. Thanks a lot! I'll send a new version. Best regards, Tiwei Bie --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2018-05-24 15:26 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-05-22 10:26 [virtio-dev] [PATCH v3] content: support SR-IOV Tiwei Bie 2018-05-22 11:03 ` [virtio-dev] " Cornelia Huck 2018-05-23 17:54 ` [virtio-dev] " Michael S. Tsirkin 2018-05-23 19:34 ` Michael S. Tsirkin 2018-05-24 0:06 ` Tiwei Bie 2018-05-24 13:44 ` Michael S. Tsirkin 2018-05-24 15:15 ` Tiwei Bie 2018-05-24 15:20 ` Michael S. Tsirkin 2018-05-24 15:27 ` Tiwei Bie
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