On Wed, Apr 27, 2022 at 01:58:20AM +0300, Max Gurtovoy wrote:
> Introduce a new mechanism to issue commands with dst_type field that is
> not "self". With the new mechanism, driver can set dst_type to 1
> and use the vdev_id common field to describe the designated vdev_id.
>
> This mechanism is useful for device groups with multiple devices
> with various different capabilities. For example, a type 1 device group
> that contains a PCI PF and its VF. For this group, a clever system
> administrator can use admin commands to manipulate the PF/VF resources.
>
> Reviewed-by: Parav Pandit <[email protected]>
> Signed-off-by: Max Gurtovoy <[email protected]>
> ---
> admin.tex | 18 ++++++++++++++----
> 1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/admin.tex b/admin.tex
> index 6725daa..f816c3b 100644
> --- a/admin.tex
> +++ b/admin.tex
> @@ -11,11 +11,13 @@ \section{Administration command set}\label{sec:Basic
> Facilities of a Virtio Devi
> le16 command;
> /*
> * 0 - self
> - * 1 - 65535 are reserved
> + * 1 - other virtio device (identified by vdev_id) in the same
> device group
> + * 2 - 65535 are reserved
> */
> le16 dst_type;
> + le64 vdev_id;
> /* reserved for common cmd fields */
> - u8 reserved[20];
> + u8 reserved[12];
> u8 command_specific_data[];
>
> /* Device-writable part */
> @@ -39,9 +41,11 @@ \section{Administration command set}\label{sec:Basic
> Facilities of a Virtio Devi
> \hline
> 03h & VIRTIO_ADMIN_STATUS_INVALID_FIELD & invalid field was set \\
> \hline
> +04h & VIRTIO_ADMIN_STATUS_INVALID_VDEV_ID & invalid vdev_id was set \\
> +\hline
> \end{tabular}
>
> -The \field{command}, \field{dst_type} and \field{command_specific_data} are
> +The \field{command}, \field{dst_type}, \field{vdev_id} and
> \field{command_specific_data} are
> set by the driver, and the device sets the \field{status}, the
> \field{command_specific_error} and the \field{command_specific_result},
> if needed.
> @@ -50,9 +54,15 @@ \section{Administration command set}\label{sec:Basic
> Facilities of a Virtio Devi
>
> The mandatory fields to be set by the driver, for all admin commands, are
> \field{command} and \field{dst_type}.
>
> +The optional unused fields to be zeroed by the driver.
> +
> The \field{command} defines the opcode for the command. The value for each
> command can be found in each command section.
>
> -The \field{dst_type} defines the designated virtio device for the command.
> This value should be set to 0 (self).
> +The \field{dst_type} defines the designated virtio device for the command.
> This value can be set to 0 (self) or 1 (other virtio device in the same device
> +group) by the driver. Not all the commands allow setting \field{dst_type} to
> 1. Refer to each command description explicitly
explicitly means nothig. just avoid using this word.
> to check whether this operation is allowed.
what this operation? I think you mean "which commands are allowed".
> +If \field{dst_type} is set to 0 by the driver, the \field{vdev_id} isn't
> valid, should be zeroed by the driver and should be ignored by the device.
> +If \field{dst_type} is set to 1 by the driver, the \field{vdev_id} is valid
> and used to describe the vdev_id of the designated virtio device (see section
> +\ref{sec:Introduction / Terminology / Device group} for vdev_id numbering
> for type 1 device groups).
should for use by conformance sections only. in fact pls add one for
this.
>
> The \field{command_specific_error} should be inspected by the driver only if
> \field{status} is set to
> VIRTIO_ADMIN_STATUS_CS_ERR by the device. In this case, the content of
> \field{command_specific_error}
> --
> 2.21.0
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