virtio — archive

[Michael S. Tsirkin]

On Wed, Feb 15, 2023 at 02:53:34AM +0200, Max Gurtovoy wrote: > > > On 13/02/2023 14:21, David Edmondson wrote: > > > > On Thursday, 2023-02-09 at 07:13:48 -05, Michael S. Tsirkin wrote: > > > @@ -1031,6 +1035,19 @@ \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{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. > > > +\item[\field{admin_queue_num}] > > > + The device uses this to report the number of the > > > + supported administration virtqueues. Virtqueues with index > > > + between \field{admin_queue_index} and (\field{admin_queue_index} + > > > + \field{admin_queue_num}) inclusive serve as administration > > > + virtqueues. > > > + Thus the number of administration virtqueues equals > > > + (\field{admin_queue_num} + 1). > > > > Really the number of queues is "admin_queue_num + 1"? > > > > That seems ... odd. > > It's not odd if we'll mention that this is a zero based value. > MST, can you add it please for the next version ? OK I can. > > > > > > + This field is valid only if VIRTIO_F_ADMIN_VQ has been > > > + negotiated. > > > \end{description} > > > \devicenormative{\paragraph}{Common configuration structure layout}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Common configuration structure layout} > > > @@ -1117,6 +1134,14 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport > > > were used before the queue reset. > > > (see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset}). > > > +If VIRTIO_F_ADMIN_VQ has been negotiated, and if the driver > > > +configures any administration virtqueues, the driver MUST > > > +configure the administration virtqueues using the index > > > +in the range \field{admin_queue_index} to > > > +\field{admin_queue_index} + \field{admin_queue_num} inclusive. > > > +The driver MAY configure less administration virtqueues than > > > +supported by the device. > > > + > > > \subsubsection{Notification structure layout}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Notification capability} > > > The notification location is found using the VIRTIO_PCI_CAP_NOTIFY_CFG > > > @@ -7684,6 +7709,15 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits} > > > \item[VIRTIO_F_ADMIN_VQ(41)] This feature indicates that the device exposes one or more > > > administration virtqueues. > > > + At the moment this feature is only supported for devices using > > > + \ref{sec:Virtio Transport Options / Virtio Over PCI > > > + Bus}~\nameref{sec:Virtio Transport Options / Virtio Over PCI Bus} > > > + as the transport and is reserved for future use for > > > + devices using other transports (see > > > + \ref{drivernormative:Basic Facilities of a Virtio Device / Feature Bits} > > > + and > > > + \ref{devicenormative:Basic Facilities of a Virtio Device / Feature Bits} for > > > + handling features reserved for future use. > > > \end{description}