To properly support VF Save/Restore procedure, fixups need to be
applied after PF driver finishes its part of VF Restore. The fixups
are required to adjust the ongoing execution for a hardware switch
that happened, because some GFX resources are not fully virtualized,
and assigned to a VF as range from a global pool. The VF on which
a VM is restored will often have different ranges provisioned than
the VF on which save process happened. Those resource fixups are
applied by the VF driver within a restored VM.
A VF driver gets informed that it was migrated by receiving an
interrupt from each GuC. The interrupt assigned for that purpose
is "GUC SW interrupt 0". Seeing that fields set from within the
irq handler should be the trigger for fixups.
The VF can safely do post-migration fixups on resources associated
to each GuC only after that GuC issued the MIGRATED interrupt.
This change introduces a worker to be used for post-migration fixups,
and a mechanism to schedule said worker when all GuCs sent the irq.
v2: renamed and moved functions, updated logged messages, removed
unused includes, used anon struct (Michal)
v3: ordering, kerneldoc, asserts, debug messages,
on_all_tiles -> on_all_gts (Michal)
v4: fixed missing header include
v5: Explained what fixups are, explained which IRQ is used, style
fixes (Michal)
Bspec: 50868
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104213449.1455694-2-tomasz.lis@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
The kernel fault injection infrastructure is used to test proper error
handling during probe. The return code of the functions using
ALLOW_ERROR_INJECTION() can be conditionnally modified at runtime by
tuning some debugfs entries. This requires CONFIG_FUNCTION_ERROR_INJECTION
(among others).
One way to use fault injection at probe time by making each of those
functions fail one at a time is:
FAILTYPE=fail_function
DEVICE="0000:00:08.0" # depends on the system
ERRNO=-12 # -ENOMEM, can depend on the function
echo N > /sys/kernel/debug/$FAILTYPE/task-filter
echo 100 > /sys/kernel/debug/$FAILTYPE/probability
echo 0 > /sys/kernel/debug/$FAILTYPE/interval
echo -1 > /sys/kernel/debug/$FAILTYPE/times
echo 0 > /sys/kernel/debug/$FAILTYPE/space
echo 1 > /sys/kernel/debug/$FAILTYPE/verbose
modprobe xe
echo $DEVICE > /sys/bus/pci/drivers/xe/unbind
grep -oP "^.* \[xe\]" /sys/kernel/debug/$FAILTYPE/injectable | \
cut -d ' ' -f 1 | while read -r FUNCTION ; do
echo "Injecting fault in $FUNCTION"
echo "" > /sys/kernel/debug/$FAILTYPE/inject
echo $FUNCTION > /sys/kernel/debug/$FAILTYPE/inject
printf %#x $ERRNO > /sys/kernel/debug/$FAILTYPE/$FUNCTION/retval
echo $DEVICE > /sys/bus/pci/drivers/xe/bind
done
rmmod xe
It will also be integrated into IGT for systematic execution by CI.
v2: Wrappers are not needed in the cases covered by this patch, so
remove them and use ALLOW_ERROR_INJECTION() directly.
v3: Document the use of fault injection at probe time in xe_pci_probe
and refer to it where ALLOW_ERROR_INJECTION() is used.
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240927151207.399354-1-francois.dugast@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Even if we have not enabled SR-IOV support using the platform
specific has_sriov flag, the hardware may still report SR-IOV
capability and the PCI layer may wrongly advertise driver support
to enable VFs. Explicitly reset the number of supported VFs to
zero to avoid confusion.
Applications may read the /sys/bus/pci/devices/.../sriov_totalvfs
prior to enabling VFs using the sriov_numvfs to check if such an
operation is possible.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240507165757.2835-1-michal.wajdeczko@intel.com
We will be adding support for the SR-IOV and driver might be then
running, in addition to existing non-virtualized bare-metal mode,
also in Physical Function (PF) or Virtual Function (VF) mode.
Since these additional modes require some changes to the driver,
define enum flag to represent different SR-IOV modes and add a
function where we will detect the actual mode in the runtime.
We start with a forced bare-metal mode as it is sufficient to
enable basic functionality and ensures no impact to existing code.
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20231115073804.1861-2-michal.wajdeczko@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
