From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-4141-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 03E7758191C8 for ; Wed, 23 May 2018 10:54:59 -0700 (PDT) Date: Wed, 23 May 2018 20:54:47 +0300 From: "Michael S. Tsirkin" Message-ID: <20180523204446-mutt-send-email-mst@kernel.org> References: <20180522102615.21339-1-tiwei.bie@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180522102615.21339-1-tiwei.bie@intel.com> Subject: Re: [virtio-dev] [PATCH v3] content: support SR-IOV To: Tiwei Bie Cc: cohuck@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, virtio-dev@lists.oasis-open.org, dan.daly@intel.com, alexander.h.duyck@intel.com, mark.d.rustad@intel.com, cunming.liang@intel.com, zhihong.wang@intel.com List-ID: 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 > Signed-off-by: Tiwei Bie > 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