Re: [virtio-comment] Re: [virtio-dev] [RFC PATCH 5/5] virtio-pci: implement VIRTIO_F_QUEUE_STATE

["Zhu, Lingshan" <lingshan.zhu@intel.com>]

On 8/14/2023 11:18 PM, Stefan Hajnoczi wrote:
> On Tue, Aug 15, 2023 at 03:29:04AM +0800, Zhu Lingshan wrote:
> > This patch adds two new le16 fields to common configruation structure
> > to support VIRTIO_F_QUEUE_STATE in PCI tranport layer.
> >
> > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> > ---
> >   transport-pci.tex | 15 +++++++++++++++
> >   1 file changed, 15 insertions(+)
> >
> > diff --git a/transport-pci.tex b/transport-pci.tex
> > index a5c6719..d9bccb0 100644
> > --- a/transport-pci.tex
> > +++ b/transport-pci.tex
> > @@ -321,6 +321,8 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> >           le64 queue_device;              /* read-write */
> >           le16 queue_notif_config_data;   /* read-only for driver */
> >           le16 queue_reset;               /* read-write */
> > +        le16 queue_avail_state;         /* read-write */
> > +        le16 queue_used_state;          /* read-write */
> >   
> >           /* About the administration virtqueue. */
> >           le16 admin_queue_index;         /* read-only for driver */
> This is an incompatible change to the register layout. Please add new
> registers at the end of struct virtio_pci_common_cfg so field offsets
> don't change for existing drivers and devices.
Oh yes, I missed that, thanks
> > @@ -415,6 +417,16 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> >           This field exists only if VIRTIO_F_RING_RESET has been
> >           negotiated. (see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset}).
> >   
> > +\item[\field{queue_avail_state}]
> > +        This field is vaild only if VIRTIO_F_QUEUE_STATE has been
> "valid"
yes
> > +        negotiated. The driver sets and gets the available state of
> > +        the virtqueue here (see \ref{sec:Virtqueues / Virtqueue State}).
> > +
> > +\item[\field{queue_used_state}]
> > +        This field is vaild only if VIRTIO_F_QUEUE_STATE has been
> "valid"
yes
> > +        negotiated. The driver sets and gets the used state of the
> > +        virtqueue here (see \ref{sec:Virtqueues / Virtqueue State}).
> > +
> >   \item[\field{admin_queue_index}]
> >           The device uses this to report the index of the first administration virtqueue.
> >           This field is valid only if VIRTIO_F_ADMIN_VQ has been negotiated.
> > @@ -488,6 +500,9 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> >   present either a value of 0 or a power of 2 in
> >   \field{queue_size}.
> >   
> > +If VIRTIO_F_QUEUE_STATE has not been negotiated, the device MUST ignore
> > +any accesses against \field{queue_avail_state} and \field{queue_used_state}.
> "accesses to"
Yes, thanks for your review
> > +
> >   If VIRTIO_F_ADMIN_VQ has been negotiated, the value
> >   \field{admin_queue_index} MUST be equal to, or bigger than
> >   \field{num_queues}; also, \field{admin_queue_num} MUST be
> > --
> > 2.35.3
> >
> >
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