Re: [PATCH v10 4/4] transport-pci: Introduce group legacy group member config region access

[Cornelia Huck <cohuck@redhat.com>]

On Thu, Jul 06 2023, Parav Pandit <parav@nvidia.com> wrote:

> diff --git a/transport-pci-legacy-regs.tex b/transport-pci-legacy-regs.tex
> new file mode 100644
> index 0000000..ceea28c
> --- /dev/null
> +++ b/transport-pci-legacy-regs.tex
> @@ -0,0 +1,42 @@
> +\subsection{Legacy Interface: Group member device Configuration Region Access}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / Legacy Interface: Group Member Device Configuration Region Access}
> +
> +The PCI owner device or the member device or both support driver notifications using

What about

"The PCI owner device, the member device, or both can choose to
support..." ?

> +a notification region defined in \field{struct virtio_pci_legacy_notify_region}.
> +
> +In \field{struct virtio_virtio_admin_cmd_legacy_notify_query_entry},
> +\field{region_data} is defined as following:
> +
> +\begin{lstlisting}
> +struct virtio_pci_legacy_notify_region {
> +        u8 owner;  /* When set to 1, notification region is of the owner device */
> +        u8 bar;    /* BAR of the member or owner device */
> +        u8 padding[6];
> +        le64 offset; /* Offset within bar. */
> +};
> +\end{lstlisting}
> +
> +The group owner device hardwires VF BAR0 to zero in the SR-IOV Extended
> +capability.
> +
> +The group member device does not use PCI BAR0 in all the Virtio PCI capabilities

"in [or for?] any of the...", I guess?

> +listed in section \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / Virtio Structure PCI Capabilities}.
> +
> +\devicenormative{\subsubsection}{Legacy Interface: Group Member Device Legacy Configuration Region Access}{Virtio Transport Options / Virtio Over PCI Bus / Legacy Interface: Group Member Device Configuration Region Access}
> +
> +When a PCI SR-IOV group owner device supports
> +VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ,
> +VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE, VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ,
> +VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE commands, the group owner device MUST
> +hardwire VF BAR0 to zero in the SR-IOV Extended capability and the group memberi

s/memberi/member/

> +device MUST NOT use BAR0 in any of the Virtio Structure PCI Capabilities.
> +
> +The group owner device or the group member device or both MAY support driver
> +notifications region.

Make this "a driver notification region"?

> +
> +For the SR-IOV group type, the owner device supporting
> +VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ,
> +VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE, VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ,
> +VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE and VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_QUERY
> +commands and its member device SHOULD follow the rules for the PCI Device ID,
> +Revision ID and Subsystem Device ID of the non-transitional devices documented in
> +section \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI Device Discovery}.