[PATCH 6.8 661/715] drm/xe: Invalidate userptr VMA on page pin fault

Sasha Levin
2024-03-24T22:45:54Z

From: Matthew Brost <matthew.brost@intel.com>

[ Upstream commit 386021394394eccef248dc5eb9c9370240821a8c ]

Rather than return an error to the user or ban the VM when userptr VMA
page pin fails with -EFAULT, invalidate VMA mappings. This supports the
UMD use case of freeing userptr while still having bindings.

Now that non-faulting VMs can invalidate VMAs, drop the usm prefix for
the tile_invalidated member.

v2:
- Fix build error (CI)
v3:
- Don't invalidate VMA if in fault mode, rather kill VM (Thomas)
- Update commit message with tile_invalidated name chagne (Thomas)
- Wait VM bookkeep slots with VM resv lock (Thomas)
v4:
- Move list_del_init(&userptr.repin_link) after error check (Thomas)
- Assert not in fault mode (Matthew)

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240312183907.933835-1-matthew.brost@intel.com
(cherry picked from commit 521db22a1d70dbc596a07544a738416025b1b63c)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/xe/xe_gt_pagefault.c | 4 ++--
drivers/gpu/drm/xe/xe_trace.h | 2 +-
drivers/gpu/drm/xe/xe_vm.c | 32 +++++++++++++++++++++-------
drivers/gpu/drm/xe/xe_vm_types.h | 7 ++----
4 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
index e2cf1759527c6..ab8536c4fd580 100644
--- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
+++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
@@ -69,7 +69,7 @@ static bool access_is_atomic(enum access_type access_type)
static bool vma_is_valid(struct xe_tile *tile, struct xe_vma *vma)
{
return BIT(tile->id) & vma->tile_present &&
- !(BIT(tile->id) & vma->usm.tile_invalidated);
+ !(BIT(tile->id) & vma->tile_invalidated);
}

static bool vma_matches(struct xe_vma *vma, u64 page_addr)
@@ -226,7 +226,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)

if (xe_vma_is_userptr(vma))
ret = xe_vma_userptr_check_repin(to_userptr_vma(vma));
- vma->usm.tile_invalidated &= ~BIT(tile->id);
+ vma->tile_invalidated &= ~BIT(tile->id);

unlock_dma_resv:
drm_exec_fini(&exec);
diff --git a/drivers/gpu/drm/xe/xe_trace.h b/drivers/gpu/drm/xe/xe_trace.h
index 4ddc55527f9ab..846f14507d5ff 100644
--- a/drivers/gpu/drm/xe/xe_trace.h
+++ b/drivers/gpu/drm/xe/xe_trace.h
@@ -468,7 +468,7 @@ DEFINE_EVENT(xe_vma, xe_vma_userptr_invalidate,
TP_ARGS(vma)
);

-DEFINE_EVENT(xe_vma, xe_vma_usm_invalidate,
+DEFINE_EVENT(xe_vma, xe_vma_invalidate,
TP_PROTO(struct xe_vma *vma),
TP_ARGS(vma)
);
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 3b21afe5b4883..a2397f232efc6 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -706,6 +706,7 @@ int xe_vm_userptr_pin(struct xe_vm *vm)
int err = 0;
LIST_HEAD(tmp_evict);

+ xe_assert(vm->xe, !xe_vm_in_fault_mode(vm));
lockdep_assert_held_write(&vm->lock);

/* Collect invalidated userptrs */
@@ -722,11 +723,27 @@ int xe_vm_userptr_pin(struct xe_vm *vm)
list_for_each_entry_safe(uvma, next, &vm->userptr.repin_list,
userptr.repin_link) {
err = xe_vma_userptr_pin_pages(uvma);
- if (err < 0)
- return err;
+ if (err == -EFAULT) {
+ list_del_init(&uvma->userptr.repin_link);

- list_del_init(&uvma->userptr.repin_link);
- list_move_tail(&uvma->vma.combined_links.rebind, &vm->rebind_list);
+ /* Wait for pending binds */
+ xe_vm_lock(vm, false);
+ dma_resv_wait_timeout(xe_vm_resv(vm),
+ DMA_RESV_USAGE_BOOKKEEP,
+ false, MAX_SCHEDULE_TIMEOUT);
+
+ err = xe_vm_invalidate_vma(&uvma->vma);
+ xe_vm_unlock(vm);
+ if (err)
+ return err;
+ } else {
+ if (err < 0)
+ return err;
+
+ list_del_init(&uvma->userptr.repin_link);
+ list_move_tail(&uvma->vma.combined_links.rebind,
+ &vm->rebind_list);
+ }
}

return 0;
@@ -2010,7 +2027,7 @@ static int xe_vm_prefetch(struct xe_vm *vm, struct xe_vma *vma,
return err;
}

- if (vma->tile_mask != (vma->tile_present & ~vma->usm.tile_invalidated)) {
+ if (vma->tile_mask != (vma->tile_present & ~vma->tile_invalidated)) {
return xe_vm_bind(vm, vma, q, xe_vma_bo(vma), syncs, num_syncs,
true, first_op, last_op);
} else {
@@ -3184,9 +3201,8 @@ int xe_vm_invalidate_vma(struct xe_vma *vma)
u8 id;
int ret;

- xe_assert(xe, xe_vm_in_fault_mode(xe_vma_vm(vma)));
xe_assert(xe, !xe_vma_is_null(vma));
- trace_xe_vma_usm_invalidate(vma);
+ trace_xe_vma_invalidate(vma);

/* Check that we don't race with page-table updates */
if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
@@ -3224,7 +3240,7 @@ int xe_vm_invalidate_vma(struct xe_vma *vma)
}
}

- vma->usm.tile_invalidated = vma->tile_mask;
+ vma->tile_invalidated = vma->tile_mask;

return 0;
}
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index 7300eea5394ba..5b96549479504 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -83,11 +83,8 @@ struct xe_vma {
struct work_struct destroy_work;
};

- /** @usm: unified shared memory state */
- struct {
- /** @tile_invalidated: VMA has been invalidated */
- u8 tile_invalidated;
- } usm;
+ /** @tile_invalidated: VMA has been invalidated */
+ u8 tile_invalidated;

/** @tile_mask: Tile mask of where to create binding for this VMA */
u8 tile_mask;
--
2.43.0