There is a remote chance that after migration, some GTs will not
send the MIGRATED interrupt, or due to current VF KMD state the
interrupt will not lead to marking the GT for recovery.
Requiring IRQs from all GTs before starting migration introduces
the possibility that the process will get stalled due to one GuC.
One could argue it is also waste of time to wait for all IRQs,
but we should get them all IRQs as soon as VGPU starts, so that's
not really an impactful argument.
Still, not waiting for all GTs makes it easier to handle situations:
* where one GuC IRQ is missing
* where state before probe is unclean - getting MIGRATED IRQ as soon
as interrupts are enabled
* where multiple migrations happen close to each other
To help with these cases, this patch alters the post-migration
recovery so that recovery task is started as soon as one GuC IRQ
is handled, and other GTs are included in recovery later as the
subsequent IRQs are serviced.
The post-migration recovery can now be called for any selection of
GTs, and it will perform recovery on all GTs for which IRQs have
arrived, even multiple times if necessary.
v2: Typos and style fixes
v3: Transferring gt_flags by value rather than reference to last
function where it is used
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Acked-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Reviewed-by: Michal Winiarski <michal.winiarski@intel.com>
Link: https://lore.kernel.org/r/20250630152155.195648-1-tomasz.lis@intel.com
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Some of our VF functions, even if they take a GT pointer, work
only on primary GT and really are tile-related and would be better
to keep them separate from the rest of true GT-oriented functions.
Move them to a file and update to take a tile pointer instead.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Tomasz Lis <tomasz.lis@intel.com>
Link: https://lore.kernel.org/r/20250602103325.549-3-michal.wajdeczko@intel.com
The post-migration recovery needs to be fully implemented for a
specific platform in order to make continuation of workloads
possible.
New platforms introduce changes which affect the recovery procedure,
and without a clear verification of support this leads to errors
with no straight forward error message explaining the cause.
This patch fixes that issue - it introduces a message to be logged
when the current driver is known to not support the current platform.
Wedging the driver immediately also decreases the amount of
additional errors which would come afterwards if the driver continued
operation.
v2: Show the message during probe as well as during recovery; do not
perform any recovery steps if the recovery is bound to fail
v3: Use SRIOV-specific logging, fix typos
v4: XE_DEBUG_SRIOV to XE_DEBUG check switch, to make testing more
straightforward
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Acked-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://lore.kernel.org/r/20250519230035.3143966-1-tomasz.lis@intel.com
During post-migration recovery of a VF, it is necessary to update
GGTT references included in messages which are going to be sent
to GuC. GuC will start consuming messages after VF KMD will inform
it about fixups being done; before that, the VF KMD is expected
to update any H2G messages which are already in send buffer but
were not consumed by GuC.
Only a small subset of messages allowed for VFs have GGTT references
in them. This patch adds the functionality to parse the CTB send
ring buffer and shift addresses contained within.
While fixing the CTB content, ct->lock is not taken. This means
the only barrier taken remains GGTT address lock - which is ok,
because only requests with GGTT addresses matter, but it also means
tail changes can happen during the CTB fixups execution (which may
be ignored as any new messages will not have anything to fix).
The GGTT address locking will be introduced in a future series.
v2: removed storing shift as that's now done in VMA nodes patch;
macros to inlines; warns to asserts; log messages fixes (Michal)
v3: removed inline keywords, enums for offsets in CTB messages,
less error messages, if return unused then made functs void (Michal)
v4: update the cached head before starting fixups
v5: removed/updated comments, wrapped lines, converted assert into
error, enums for offsets to separate patch, reused xe_map_rd
v6: define xe_map_*_array() macros, support CTB wrap which divides
a message, updated comments, moved one function to an earlier patch
v7: renamed few functions, wider use on previously introduced helper,
separate cases in parsing messges, documented a static funct
v8: Introduced more helpers, fixed coding style mistakes
v9: Move xe_map*() functs to macros, add asserts, add debug print
v10: Errors in place of some asserts, style fixes
v11: Fixed invalid conditionals, added debug-only local pointer
v12: Removed redundant __maybe_unused
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://lore.kernel.org/r/20250512114018.361843-5-tomasz.lis@intel.com
We have only one GGTT for all IOV functions, with each VF having assigned
a range of addresses for its use. After migration, a VF can receive a
different range of addresses than it had initially.
This implements shifting GGTT addresses within drm_mm nodes, so that
VMAs stay valid after migration. This will make the driver use new
addresses when accessing GGTT from the moment the shifting ends.
By taking the ggtt->lock for the period of VMA fixups, this change
also adds constraint on that mutex. Any locks used during the recovery
cannot ever wait for hardware response - because after migration,
the hardware will not do anything until fixups are finished.
v2: Moved some functs to xe_ggtt.c; moved shift computation to just
after querying; improved documentation; switched some warns to asserts;
skipping fixups when GGTT shift eq 0; iterating through tiles (Michal)
v3: Updated kerneldocs, removed unused funct, properly allocate
balloning nodes if non existent
v4: Re-used ballooning functions from VF init, used bool in place of
standard error codes
v5: Renamed one function
v6: Subject tag change, several kerneldocs updated, some functions
renamed, some moved, added several asserts, shuffled declarations
of variables, revealed more detail in high level functions
v7: Fixed typos, added `_locked` suffix to some functs, improved
readability of asserts, removed unneeded conditional
v8: Moved one function, removed implementation detail from kerneldoc,
added asserts
v9: Code shuffling without much change, and one param rename
v10: Minor error path change, added printing the shift via debugfs
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://lore.kernel.org/r/20250512114018.361843-3-tomasz.lis@intel.com
If another VF migration happened during post-migration recovery,
then the current worker should be finished to allow the next
one start swiftly and cleanly.
Check for defer in two places: before fixups, and before
sending RESFIX_DONE.
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104213449.1455694-6-tomasz.lis@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
During post-migration recovery, only MMIO communication to GuC is
allowed. The VF KMD needs to use that channel to ask for the new
provisioning, which includes a new GGTT range assigned to the VF.
v2: query config only instead of handshake; no need to get pm ref as
it's now kept through whole recovery (Michal)
v3: switched names of 'err' and 'ret' (Michal)
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104213449.1455694-5-tomasz.lis@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
After restore, GuC will not answer to any messages from VF KMD until
fixups are applied. When that is done, VF KMD sends RESFIX_DONE
message to GuC, at which point GuC resumes normal operation.
This patch implements sending the RESFIX_DONE message at end of
post-migration recovery.
v2: keep pm ref during whole recovery, style fixes (Michal)
v3: assert removal to separate patch, debug message per GuC instead
of one, comments changes (Michal)
v4: improve one debug message (Michal)
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104213449.1455694-4-tomasz.lis@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
This adds a documentation chapter, containing high level flow
of VF restore procedure.
v2: Better describe initial conditions, include GuC states on
sequence diagram (Michal)
v3: moved DOC to .c (Michal)
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104213449.1455694-3-tomasz.lis@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
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>
