[virtio-dev] Re: [PATCH 3/5] virtqueue: constraints for virtqueue state

Michael S. Tsirkin
2023-09-14T11:30:13Z

On Wed, Sep 06, 2023 at 04:16:35PM +0800, Zhu Lingshan wrote:
> This commit specifies the constraints of the virtqueue state,
> and the actions should be taken by the device when SUSPEND
> and DRIVER_OK is set
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
> content.tex | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/content.tex b/content.tex
> index 0fab537..9d727ce 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -594,6 +594,25 @@ \subsection{\field{Used State} Field}
> When VIRTIO_RING_F_PACKED is not negotiated, the 16-bit value of \field{used_idx}
> is always 0
>
> +\drivernormative{\subsection}{Virtqueue State}{Basic Facilities of a Virtio Device / Virtqueue State}
> +
> +If VIRTIO_F_QUEUE_STATE has been negotiated but VIRTIO_RING_F_PACKED not been negotiated,
> +the driver SHOULD NOT access \field{Used State} of any virtqueues, it SHOULD use the
> +used index in the used ring.
> +
> +\devicenormative{\subsection}{Virtqueue State}{Basic Facilities of a Virtio Device / Virtqueue State}
> +
> +If VIRTIO_F_QUEUE_STATE has been negotiated, the device SHOULD only accept setting
> +Virtqueue State of any virtqueues when DRIVER_OK is not set in \field{device status},
> +or both of DRIVER_OK and SUSPEND are set in \field{device status}.
> +Otherwise the device MUST ignore any writes to Virtqueue State of any virtqueues.
> +
> +If VIRTIO_F_QUEUE_STATE have been negotiated, when SUSPEND is set,
> +the device MUST record the Virtqueue State of every enabled virtqueue
> +in \field{Available State} and \field{Used State} respectively,

record how?

> +and correspondingly restore the Virtqueue State of every enabled virtqueue
> +from \field{Available State} and \field{Used State} when DRIVER_OK is set.

when is that?

> +
> \input{admin.tex}
>
> \chapter{General Initialization And Device Operation}\label{sec:General Initialization And Device Operation}
> --
> 2.35.3