While some VF/PF relay actions must be handled on the GT level,
like query for runtime registers, it was clarified by the arch
team that initial version negotiation can be done by the VF just
once, by using any available GuC/GT.

Move handling of the VF/PF ABI version negotiation on the PF side
from the GT level functions to the device level functions.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/20250713103625.1964-7-michal.wajdeczko@intel.com

Since usually pausing the VF is done as a first step to migrate
that VF, immediately save VF GuC state as a final step of the VF
pausing to have that data ready to export when needed.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240912203817.1880-5-michal.wajdeczko@intel.com

Some VF accessible registers (like GuC scratch registers) must be
explicitly reset during the FLR. While this is today done by the GuC
firmware, according to the design, this should be responsibility of
the PF driver, as future platforms may require more registers to be
reset. Likewise GuC, the PF can access VFs registers by adding some
platform specific offset to the original register address.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240902192953.1792-1-michal.wajdeczko@intel.com

Our initial VF control implementation was focused on providing
a very minimal support for the VF_STATE_NOTIFY events just to
meet GuC requirements, without tracking a VF state or doing any
expected actions (like cleanup in case of the FLR notification).

Try to improve this by defining set of VF state machines, each
responsible for processing one activity (PAUSE, RESUME, STOP or
FLR). All required steps defined by the VF state machine are then
executed by the PF worker from the dedicated workqueue.

Any external requests or notifications simply try to transition
between the states to trigger a work and then wait for that work
to finish. Some predefined default timeouts are used to avoid
changing existing API calls, but it should be easy to extend the
control API to also accept specific timeout values.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240828210809.1528-5-michal.wajdeczko@intel.com

It is unlikely that GuC will ever send a G2H notification with an
invalid VFID and it is currently harmless if that actually happen.
But in upcoming patches we will start using that VFID as an index
and we must be sure it is a valid to avoid a crash due to a buggy
firmware or a currupted G2H message.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240828210809.1528-4-michal.wajdeczko@intel.com

Current formatting of "The VF FLR Flow with GuC" only looks fine,
but it will not render properly when included in htmldocs due to:

  WARNING: Block quote ends without a blank line; unexpected unindent.
  CRITICAL: Missing matching underline for section title overline.

Fix that by adding proper indent and using list markup.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240828210809.1528-3-michal.wajdeczko@intel.com

We attempt to unprovision all VFs GuC when disabling them, but
GuC may reject such request if the target VF was previously active
but VF driver didn't unload with explicit VF reset H2G action or
the VMM has not started the VF FLR.

To avoid mismatches between configs maintained the PF and GuC,
trigger an explicit FLR sequences just before releasing resources.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240625194546.1301-2-michal.wajdeczko@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

GuC will use VF_STATE_NOTIFY events to notify the PF about changes
of the VF state, in particular when a VF FLR was requested.  Add
very minimal support for such events to avoid reporting errors due
to unexpected G2H. We will improve handling of these messages later.

While around also add few basic functions to control the VF state
(pause, resume, stop) as we will also exercise them soon.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326191518.363-3-michal.wajdeczko@intel.com