[PATCH 0/9] remove rcu support from i915_address_space

[PATCH 0/9] remove rcu support from i915_address_space

[Daniel Vetter]

Hi all,

Next round with some fixes:
- missed a conversion, 0day spotted it running sparse
- missed virtual engines in the last patch, intel-gfx-ci spotted that too
  (except it was mostly filtered out by a bogus cibuglog entry, so took a
  while to realize what's going on).

Old version:

https://lore.kernel.org/dri-devel/20210802154806.3710472-1-daniel.vetter@ffwll.ch/

Cheers, Daniel

Daniel Vetter (9):
  drm/i915: Drop code to handle set-vm races from execbuf
  drm/i915: Rename i915_gem_context_get_vm_rcu to
    i915_gem_context_get_eb_vm
  drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam
  drm/i915: Add i915_gem_context_is_full_ppgtt
  drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem
  drm/i915: Drop __rcu from gem_context->vm
  drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups
  drm/i915: Stop rcu support for i915_address_space
  drm/i915: Split out intel_context_create_user

 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 86 ++++---------------
 drivers/gpu/drm/i915/gem/i915_gem_context.h   | 13 ++-
 .../gpu/drm/i915/gem/i915_gem_context_types.h |  2 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 12 ++-
 .../gpu/drm/i915/gem/selftests/huge_pages.c   |  8 +-
 .../drm/i915/gem/selftests/i915_gem_context.c | 34 +++-----
 .../gpu/drm/i915/gem/selftests/mock_context.c |  2 +-
 drivers/gpu/drm/i915/gt/intel_context.c       | 22 ++++-
 drivers/gpu/drm/i915/gt/intel_context.h       |  2 +
 drivers/gpu/drm/i915/gt/intel_engine.h        |  4 +
 drivers/gpu/drm/i915/gt/intel_engine_cs.c     | 21 ++++-
 drivers/gpu/drm/i915/gt/intel_ggtt.c          |  1 -
 drivers/gpu/drm/i915/gt/intel_gtt.c           |  6 +-
 drivers/gpu/drm/i915/gt/intel_gtt.h           |  2 +-
 drivers/gpu/drm/i915/gt/selftest_execlists.c  |  2 +-
 drivers/gpu/drm/i915/gt/selftest_hangcheck.c  |  2 +-
 drivers/gpu/drm/i915/i915_drv.h               |  4 +-
 drivers/gpu/drm/i915/i915_trace.h             |  2 +-
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c |  4 +-
 drivers/gpu/drm/i915/selftests/i915_vma.c     |  4 +-
 20 files changed, 105 insertions(+), 128 deletions(-)

-- 
2.32.0

[Intel-gfx] [PATCH 0/9] remove rcu support from i915_address_space

[Daniel Vetter]

Hi all,

Next round with some fixes:
- missed a conversion, 0day spotted it running sparse
- missed virtual engines in the last patch, intel-gfx-ci spotted that too
  (except it was mostly filtered out by a bogus cibuglog entry, so took a
  while to realize what's going on).

Old version:

https://lore.kernel.org/dri-devel/20210802154806.3710472-1-daniel.vetter@ffwll.ch/

Cheers, Daniel

Daniel Vetter (9):
  drm/i915: Drop code to handle set-vm races from execbuf
  drm/i915: Rename i915_gem_context_get_vm_rcu to
    i915_gem_context_get_eb_vm
  drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam
  drm/i915: Add i915_gem_context_is_full_ppgtt
  drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem
  drm/i915: Drop __rcu from gem_context->vm
  drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups
  drm/i915: Stop rcu support for i915_address_space
  drm/i915: Split out intel_context_create_user

 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 86 ++++---------------
 drivers/gpu/drm/i915/gem/i915_gem_context.h   | 13 ++-
 .../gpu/drm/i915/gem/i915_gem_context_types.h |  2 +-
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 12 ++-
 .../gpu/drm/i915/gem/selftests/huge_pages.c   |  8 +-
 .../drm/i915/gem/selftests/i915_gem_context.c | 34 +++-----
 .../gpu/drm/i915/gem/selftests/mock_context.c |  2 +-
 drivers/gpu/drm/i915/gt/intel_context.c       | 22 ++++-
 drivers/gpu/drm/i915/gt/intel_context.h       |  2 +
 drivers/gpu/drm/i915/gt/intel_engine.h        |  4 +
 drivers/gpu/drm/i915/gt/intel_engine_cs.c     | 21 ++++-
 drivers/gpu/drm/i915/gt/intel_ggtt.c          |  1 -
 drivers/gpu/drm/i915/gt/intel_gtt.c           |  6 +-
 drivers/gpu/drm/i915/gt/intel_gtt.h           |  2 +-
 drivers/gpu/drm/i915/gt/selftest_execlists.c  |  2 +-
 drivers/gpu/drm/i915/gt/selftest_hangcheck.c  |  2 +-
 drivers/gpu/drm/i915/i915_drv.h               |  4 +-
 drivers/gpu/drm/i915/i915_trace.h             |  2 +-
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c |  4 +-
 drivers/gpu/drm/i915/selftests/i915_vma.c     |  4 +-
 20 files changed, 105 insertions(+), 128 deletions(-)

-- 
2.32.0

[PATCH v2 1/9] drm/i915: Drop code to handle set-vm races from execbuf

[Daniel Vetter]

Changing the vm from a finalized gem ctx is no longer possible, which
means we don't have to check for that anymore.

I was pondering whether to keep the check as a WARN_ON, but things go
boom real bad real fast if the vm of a vma is wrong. Plus we'd need to
also get the ggtt vm for !full-ppgtt platforms. Ditching it all seemed
like a better idea.

References: ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 538d9d2e52b7..69e47b97d786 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -775,11 +775,7 @@ static int __eb_add_lut(struct i915_execbuffer *eb,
 	/* Check that the context hasn't been closed in the meantime */
 	err = -EINTR;
 	if (!mutex_lock_interruptible(&ctx->lut_mutex)) {
-		struct i915_address_space *vm = rcu_access_pointer(ctx->vm);
-
-		if (unlikely(vm && vma->vm != vm))
-			err = -EAGAIN; /* user racing with ctx set-vm */
-		else if (likely(!i915_gem_context_is_closed(ctx)))
+		if (likely(!i915_gem_context_is_closed(ctx)))
 			err = radix_tree_insert(&ctx->handles_vma, handle, vma);
 		else
 			err = -ENOENT;
-- 
2.32.0

[Intel-gfx] [PATCH v2 1/9] drm/i915: Drop code to handle set-vm races from execbuf

[Daniel Vetter]

Changing the vm from a finalized gem ctx is no longer possible, which
means we don't have to check for that anymore.

I was pondering whether to keep the check as a WARN_ON, but things go
boom real bad real fast if the vm of a vma is wrong. Plus we'd need to
also get the ggtt vm for !full-ppgtt platforms. Ditching it all seemed
like a better idea.

References: ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 538d9d2e52b7..69e47b97d786 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -775,11 +775,7 @@ static int __eb_add_lut(struct i915_execbuffer *eb,
 	/* Check that the context hasn't been closed in the meantime */
 	err = -EINTR;
 	if (!mutex_lock_interruptible(&ctx->lut_mutex)) {
-		struct i915_address_space *vm = rcu_access_pointer(ctx->vm);
-
-		if (unlikely(vm && vma->vm != vm))
-			err = -EAGAIN; /* user racing with ctx set-vm */
-		else if (likely(!i915_gem_context_is_closed(ctx)))
+		if (likely(!i915_gem_context_is_closed(ctx)))
 			err = radix_tree_insert(&ctx->handles_vma, handle, vma);
 		else
 			err = -ENOENT;
-- 
2.32.0

[PATCH v2 2/9] drm/i915: Rename i915_gem_context_get_vm_rcu to i915_gem_context_get_eb_vm

[Daniel Vetter]

The important part isn't so much that this does an rcu lookup - that's
more an implementation detail, which will also be removed.

The thing that makes this different from other functions is that it's
gettting you the vm that batchbuffers will run in for that gem
context, which is either a full ppgtt stored in gem->ctx, or the ggtt.

We'll make more use of this function later on.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.h           | 2 +-
 drivers/gpu/drm/i915/gem/selftests/huge_pages.c       | 4 ++--
 drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 4 ++--
 drivers/gpu/drm/i915/gt/selftest_execlists.c          | 2 +-
 drivers/gpu/drm/i915/gt/selftest_hangcheck.c          | 2 +-
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c         | 4 ++--
 drivers/gpu/drm/i915/selftests/i915_vma.c             | 2 +-
 7 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 18060536b0c2..da6e8b506d96 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -155,7 +155,7 @@ i915_gem_context_vm(struct i915_gem_context *ctx)
 }
 
 static inline struct i915_address_space *
-i915_gem_context_get_vm_rcu(struct i915_gem_context *ctx)
+i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
 	struct i915_address_space *vm;
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index a094f3ce1a90..6c68fe26bb32 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1456,7 +1456,7 @@ static int igt_tmpfs_fallback(void *arg)
 	struct i915_gem_context *ctx = arg;
 	struct drm_i915_private *i915 = ctx->i915;
 	struct vfsmount *gemfs = i915->mm.gemfs;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	u32 *vaddr;
@@ -1512,7 +1512,7 @@ static int igt_shrink_thp(void *arg)
 {
 	struct i915_gem_context *ctx = arg;
 	struct drm_i915_private *i915 = ctx->i915;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_gem_engines_iter it;
 	struct intel_context *ce;
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 8eb5050f8cb3..d436ce7fa25c 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -1528,7 +1528,7 @@ static int write_to_scratch(struct i915_gem_context *ctx,
 
 	intel_gt_chipset_flush(engine->gt);
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	vma = i915_vma_instance(obj, vm, NULL);
 	if (IS_ERR(vma)) {
 		err = PTR_ERR(vma);
@@ -1607,7 +1607,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
 	if (GRAPHICS_VER(i915) >= 8) {
 		const u32 GPR0 = engine->mmio_base + 0x600;
 
-		vm = i915_gem_context_get_vm_rcu(ctx);
+		vm = i915_gem_context_get_eb_vm(ctx);
 		vma = i915_vma_instance(obj, vm, NULL);
 		if (IS_ERR(vma)) {
 			err = PTR_ERR(vma);
diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c
index f12ffe797639..b3863abc51f5 100644
--- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
+++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
@@ -3493,7 +3493,7 @@ static int smoke_submit(struct preempt_smoke *smoke,
 	if (batch) {
 		struct i915_address_space *vm;
 
-		vm = i915_gem_context_get_vm_rcu(ctx);
+		vm = i915_gem_context_get_eb_vm(ctx);
 		vma = i915_vma_instance(batch, vm, NULL);
 		i915_vm_put(vm);
 		if (IS_ERR(vma))
diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
index 08f011f893b2..6023c418ee8a 100644
--- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
+++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
@@ -117,7 +117,7 @@ static struct i915_request *
 hang_create_request(struct hang *h, struct intel_engine_cs *engine)
 {
 	struct intel_gt *gt = h->gt;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(h->ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(h->ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_request *rq = NULL;
 	struct i915_vma *hws, *vma;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index f843a5040706..2d60a5a5b065 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1300,7 +1300,7 @@ static int exercise_mock(struct drm_i915_private *i915,
 	if (!ctx)
 		return -ENOMEM;
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	err = func(vm, 0, min(vm->total, limit), end_time);
 	i915_vm_put(vm);
 
@@ -1848,7 +1848,7 @@ static int igt_cs_tlb(void *arg)
 		goto out_unlock;
 	}
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	if (i915_is_ggtt(vm))
 		goto out_vm;
 
diff --git a/drivers/gpu/drm/i915/selftests/i915_vma.c b/drivers/gpu/drm/i915/selftests/i915_vma.c
index dd0607254a95..79ba72da0813 100644
--- a/drivers/gpu/drm/i915/selftests/i915_vma.c
+++ b/drivers/gpu/drm/i915/selftests/i915_vma.c
@@ -118,7 +118,7 @@ static int create_vmas(struct drm_i915_private *i915,
 				struct i915_vma *vma;
 				int err;
 
-				vm = i915_gem_context_get_vm_rcu(ctx);
+				vm = i915_gem_context_get_eb_vm(ctx);
 				vma = checked_vma_instance(obj, vm, NULL);
 				i915_vm_put(vm);
 				if (IS_ERR(vma))
-- 
2.32.0

[Intel-gfx] [PATCH v2 2/9] drm/i915: Rename i915_gem_context_get_vm_rcu to i915_gem_context_get_eb_vm

[Daniel Vetter]

The important part isn't so much that this does an rcu lookup - that's
more an implementation detail, which will also be removed.

The thing that makes this different from other functions is that it's
gettting you the vm that batchbuffers will run in for that gem
context, which is either a full ppgtt stored in gem->ctx, or the ggtt.

We'll make more use of this function later on.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.h           | 2 +-
 drivers/gpu/drm/i915/gem/selftests/huge_pages.c       | 4 ++--
 drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 4 ++--
 drivers/gpu/drm/i915/gt/selftest_execlists.c          | 2 +-
 drivers/gpu/drm/i915/gt/selftest_hangcheck.c          | 2 +-
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c         | 4 ++--
 drivers/gpu/drm/i915/selftests/i915_vma.c             | 2 +-
 7 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 18060536b0c2..da6e8b506d96 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -155,7 +155,7 @@ i915_gem_context_vm(struct i915_gem_context *ctx)
 }
 
 static inline struct i915_address_space *
-i915_gem_context_get_vm_rcu(struct i915_gem_context *ctx)
+i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
 	struct i915_address_space *vm;
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index a094f3ce1a90..6c68fe26bb32 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1456,7 +1456,7 @@ static int igt_tmpfs_fallback(void *arg)
 	struct i915_gem_context *ctx = arg;
 	struct drm_i915_private *i915 = ctx->i915;
 	struct vfsmount *gemfs = i915->mm.gemfs;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	u32 *vaddr;
@@ -1512,7 +1512,7 @@ static int igt_shrink_thp(void *arg)
 {
 	struct i915_gem_context *ctx = arg;
 	struct drm_i915_private *i915 = ctx->i915;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_gem_engines_iter it;
 	struct intel_context *ce;
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 8eb5050f8cb3..d436ce7fa25c 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -1528,7 +1528,7 @@ static int write_to_scratch(struct i915_gem_context *ctx,
 
 	intel_gt_chipset_flush(engine->gt);
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	vma = i915_vma_instance(obj, vm, NULL);
 	if (IS_ERR(vma)) {
 		err = PTR_ERR(vma);
@@ -1607,7 +1607,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
 	if (GRAPHICS_VER(i915) >= 8) {
 		const u32 GPR0 = engine->mmio_base + 0x600;
 
-		vm = i915_gem_context_get_vm_rcu(ctx);
+		vm = i915_gem_context_get_eb_vm(ctx);
 		vma = i915_vma_instance(obj, vm, NULL);
 		if (IS_ERR(vma)) {
 			err = PTR_ERR(vma);
diff --git a/drivers/gpu/drm/i915/gt/selftest_execlists.c b/drivers/gpu/drm/i915/gt/selftest_execlists.c
index f12ffe797639..b3863abc51f5 100644
--- a/drivers/gpu/drm/i915/gt/selftest_execlists.c
+++ b/drivers/gpu/drm/i915/gt/selftest_execlists.c
@@ -3493,7 +3493,7 @@ static int smoke_submit(struct preempt_smoke *smoke,
 	if (batch) {
 		struct i915_address_space *vm;
 
-		vm = i915_gem_context_get_vm_rcu(ctx);
+		vm = i915_gem_context_get_eb_vm(ctx);
 		vma = i915_vma_instance(batch, vm, NULL);
 		i915_vm_put(vm);
 		if (IS_ERR(vma))
diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
index 08f011f893b2..6023c418ee8a 100644
--- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
+++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
@@ -117,7 +117,7 @@ static struct i915_request *
 hang_create_request(struct hang *h, struct intel_engine_cs *engine)
 {
 	struct intel_gt *gt = h->gt;
-	struct i915_address_space *vm = i915_gem_context_get_vm_rcu(h->ctx);
+	struct i915_address_space *vm = i915_gem_context_get_eb_vm(h->ctx);
 	struct drm_i915_gem_object *obj;
 	struct i915_request *rq = NULL;
 	struct i915_vma *hws, *vma;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index f843a5040706..2d60a5a5b065 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1300,7 +1300,7 @@ static int exercise_mock(struct drm_i915_private *i915,
 	if (!ctx)
 		return -ENOMEM;
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	err = func(vm, 0, min(vm->total, limit), end_time);
 	i915_vm_put(vm);
 
@@ -1848,7 +1848,7 @@ static int igt_cs_tlb(void *arg)
 		goto out_unlock;
 	}
 
-	vm = i915_gem_context_get_vm_rcu(ctx);
+	vm = i915_gem_context_get_eb_vm(ctx);
 	if (i915_is_ggtt(vm))
 		goto out_vm;
 
diff --git a/drivers/gpu/drm/i915/selftests/i915_vma.c b/drivers/gpu/drm/i915/selftests/i915_vma.c
index dd0607254a95..79ba72da0813 100644
--- a/drivers/gpu/drm/i915/selftests/i915_vma.c
+++ b/drivers/gpu/drm/i915/selftests/i915_vma.c
@@ -118,7 +118,7 @@ static int create_vmas(struct drm_i915_private *i915,
 				struct i915_vma *vma;
 				int err;
 
-				vm = i915_gem_context_get_vm_rcu(ctx);
+				vm = i915_gem_context_get_eb_vm(ctx);
 				vma = checked_vma_instance(obj, vm, NULL);
 				i915_vm_put(vm);
 				if (IS_ERR(vma))
-- 
2.32.0

[PATCH v2 3/9] drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam

[Daniel Vetter]

Consolidates the "which is the vm my execbuf runs in" code a bit. We
do some get/put which isn't really required, but all the other users
want the refcounting, and I figured doing a function just for this
getparam to avoid 2 atomis is a bit much.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index cff72679ad7c..6263563e15d6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2124,6 +2124,7 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 	struct drm_i915_gem_context_param *args = data;
 	struct i915_gem_context *ctx;
+	struct i915_address_space *vm;
 	int ret = 0;
 
 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
@@ -2133,12 +2134,10 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 	switch (args->param) {
 	case I915_CONTEXT_PARAM_GTT_SIZE:
 		args->size = 0;
-		rcu_read_lock();
-		if (rcu_access_pointer(ctx->vm))
-			args->value = rcu_dereference(ctx->vm)->total;
-		else
-			args->value = to_i915(dev)->ggtt.vm.total;
-		rcu_read_unlock();
+		vm = i915_gem_context_get_eb_vm(ctx);
+		args->value = vm->total;
+		i915_vm_put(vm);
+
 		break;
 
 	case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
-- 
2.32.0

[Intel-gfx] [PATCH v2 3/9] drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam

[Daniel Vetter]

Consolidates the "which is the vm my execbuf runs in" code a bit. We
do some get/put which isn't really required, but all the other users
want the refcounting, and I figured doing a function just for this
getparam to avoid 2 atomis is a bit much.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index cff72679ad7c..6263563e15d6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2124,6 +2124,7 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 	struct drm_i915_gem_context_param *args = data;
 	struct i915_gem_context *ctx;
+	struct i915_address_space *vm;
 	int ret = 0;
 
 	ctx = i915_gem_context_lookup(file_priv, args->ctx_id);
@@ -2133,12 +2134,10 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
 	switch (args->param) {
 	case I915_CONTEXT_PARAM_GTT_SIZE:
 		args->size = 0;
-		rcu_read_lock();
-		if (rcu_access_pointer(ctx->vm))
-			args->value = rcu_dereference(ctx->vm)->total;
-		else
-			args->value = to_i915(dev)->ggtt.vm.total;
-		rcu_read_unlock();
+		vm = i915_gem_context_get_eb_vm(ctx);
+		args->value = vm->total;
+		i915_vm_put(vm);
+
 		break;
 
 	case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
-- 
2.32.0

[PATCH v2 4/9] drm/i915: Add i915_gem_context_is_full_ppgtt

[Daniel Vetter]

And use it anywhere we have open-coded checks for ctx->vm that really
only check for full ppgtt.

Plus for paranoia add a GEM_BUG_ON that checks it's really only set
when we have full ppgtt, just in case. gem_context->vm is different
since it's NULL in ggtt mode, unlike intel_context->vm or gt->vm,
which is always set.

v2: 0day found a testcase that I missed.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c           | 2 +-
 drivers/gpu/drm/i915/gem/i915_gem_context.h           | 7 +++++++
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c        | 2 +-
 drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 6 +++---
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 6263563e15d6..a80b06c98dba 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1581,7 +1581,7 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	int err;
 	u32 id;
 
-	if (!rcu_access_pointer(ctx->vm))
+	if (!i915_gem_context_is_full_ppgtt(ctx))
 		return -ENODEV;
 
 	rcu_read_lock();
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index da6e8b506d96..37536a260e6e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -154,6 +154,13 @@ i915_gem_context_vm(struct i915_gem_context *ctx)
 	return rcu_dereference_protected(ctx->vm, lockdep_is_held(&ctx->mutex));
 }
 
+static inline bool i915_gem_context_is_full_ppgtt(struct i915_gem_context *ctx)
+{
+	GEM_BUG_ON(!!rcu_access_pointer(ctx->vm) != HAS_FULL_PPGTT(ctx->i915));
+
+	return !!rcu_access_pointer(ctx->vm);
+}
+
 static inline struct i915_address_space *
 i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 69e47b97d786..bdf2b5785a81 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -749,7 +749,7 @@ static int eb_select_context(struct i915_execbuffer *eb)
 		return PTR_ERR(ctx);
 
 	eb->gem_context = ctx;
-	if (rcu_access_pointer(ctx->vm))
+	if (i915_gem_context_is_full_ppgtt(ctx))
 		eb->invalid_flags |= EXEC_OBJECT_NEEDS_GTT;
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index d436ce7fa25c..0708b9cdeb9f 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -704,7 +704,7 @@ static int igt_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -838,7 +838,7 @@ static int igt_shared_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -1417,7 +1417,7 @@ static int igt_ctx_readonly(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       ce->engine->name,
-				       yesno(!!ctx_vm(ctx)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				i915_gem_context_unlock_engines(ctx);
 				goto out_file;
-- 
2.32.0

[Intel-gfx] [PATCH v2 4/9] drm/i915: Add i915_gem_context_is_full_ppgtt

[Daniel Vetter]

And use it anywhere we have open-coded checks for ctx->vm that really
only check for full ppgtt.

Plus for paranoia add a GEM_BUG_ON that checks it's really only set
when we have full ppgtt, just in case. gem_context->vm is different
since it's NULL in ggtt mode, unlike intel_context->vm or gt->vm,
which is always set.

v2: 0day found a testcase that I missed.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c           | 2 +-
 drivers/gpu/drm/i915/gem/i915_gem_context.h           | 7 +++++++
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c        | 2 +-
 drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c | 6 +++---
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 6263563e15d6..a80b06c98dba 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1581,7 +1581,7 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	int err;
 	u32 id;
 
-	if (!rcu_access_pointer(ctx->vm))
+	if (!i915_gem_context_is_full_ppgtt(ctx))
 		return -ENODEV;
 
 	rcu_read_lock();
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index da6e8b506d96..37536a260e6e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -154,6 +154,13 @@ i915_gem_context_vm(struct i915_gem_context *ctx)
 	return rcu_dereference_protected(ctx->vm, lockdep_is_held(&ctx->mutex));
 }
 
+static inline bool i915_gem_context_is_full_ppgtt(struct i915_gem_context *ctx)
+{
+	GEM_BUG_ON(!!rcu_access_pointer(ctx->vm) != HAS_FULL_PPGTT(ctx->i915));
+
+	return !!rcu_access_pointer(ctx->vm);
+}
+
 static inline struct i915_address_space *
 i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 69e47b97d786..bdf2b5785a81 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -749,7 +749,7 @@ static int eb_select_context(struct i915_execbuffer *eb)
 		return PTR_ERR(ctx);
 
 	eb->gem_context = ctx;
-	if (rcu_access_pointer(ctx->vm))
+	if (i915_gem_context_is_full_ppgtt(ctx))
 		eb->invalid_flags |= EXEC_OBJECT_NEEDS_GTT;
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index d436ce7fa25c..0708b9cdeb9f 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -704,7 +704,7 @@ static int igt_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -838,7 +838,7 @@ static int igt_shared_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -1417,7 +1417,7 @@ static int igt_ctx_readonly(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       ce->engine->name,
-				       yesno(!!ctx_vm(ctx)),
+				       yesno(i915_gem_context_is_full_ppgtt(ctx)),
 				       err);
 				i915_gem_context_unlock_engines(ctx);
 				goto out_file;
-- 
2.32.0

[PATCH v2 5/9] drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem

[Daniel Vetter]

Since

commit ccbc1b97948ab671335e950271e39766729736c3
Author: Jason Ekstrand <jason@jlekstrand.net>
Date:   Thu Jul 8 10:48:30 2021 -0500

    drm/i915/gem: Don't allow changing the VM on running contexts (v4)

the gem_ctx->vm can't change anymore. Plus we always set the
intel_context->vm, so might as well use the helper we have for that.

This makes it very clear that we always overwrite intel_context->vm
for userspace contexts, since the default is gt->vm, which is
explicitly reserved for kernel context use. It would be good to split
things up a bit further and avoid any possibility for an accident
where we run kernel stuff in userspace vm or the other way round.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index a80b06c98dba..fd24a1236682 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -784,16 +784,8 @@ static int intel_context_set_gem(struct intel_context *ce,
 
 	ce->ring_size = SZ_16K;
 
-	if (rcu_access_pointer(ctx->vm)) {
-		struct i915_address_space *vm;
-
-		rcu_read_lock();
-		vm = context_get_vm_rcu(ctx); /* hmm */
-		rcu_read_unlock();
-
-		i915_vm_put(ce->vm);
-		ce->vm = vm;
-	}
+	i915_vm_put(ce->vm);
+	ce->vm = i915_gem_context_get_eb_vm(ctx);
 
 	if (ctx->sched.priority >= I915_PRIORITY_NORMAL &&
 	    intel_engine_has_timeslices(ce->engine) &&
-- 
2.32.0

[Intel-gfx] [PATCH v2 5/9] drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem

[Daniel Vetter]

Since

commit ccbc1b97948ab671335e950271e39766729736c3
Author: Jason Ekstrand <jason@jlekstrand.net>
Date:   Thu Jul 8 10:48:30 2021 -0500

    drm/i915/gem: Don't allow changing the VM on running contexts (v4)

the gem_ctx->vm can't change anymore. Plus we always set the
intel_context->vm, so might as well use the helper we have for that.

This makes it very clear that we always overwrite intel_context->vm
for userspace contexts, since the default is gt->vm, which is
explicitly reserved for kernel context use. It would be good to split
things up a bit further and avoid any possibility for an accident
where we run kernel stuff in userspace vm or the other way round.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index a80b06c98dba..fd24a1236682 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -784,16 +784,8 @@ static int intel_context_set_gem(struct intel_context *ce,
 
 	ce->ring_size = SZ_16K;
 
-	if (rcu_access_pointer(ctx->vm)) {
-		struct i915_address_space *vm;
-
-		rcu_read_lock();
-		vm = context_get_vm_rcu(ctx); /* hmm */
-		rcu_read_unlock();
-
-		i915_vm_put(ce->vm);
-		ce->vm = vm;
-	}
+	i915_vm_put(ce->vm);
+	ce->vm = i915_gem_context_get_eb_vm(ctx);
 
 	if (ctx->sched.priority >= I915_PRIORITY_NORMAL &&
 	    intel_engine_has_timeslices(ce->engine) &&
-- 
2.32.0

[PATCH v2 6/9] drm/i915: Drop __rcu from gem_context->vm

[Daniel Vetter]

It's been invariant since

    commit ccbc1b97948ab671335e950271e39766729736c3
    Author: Jason Ekstrand <jason@jlekstrand.net>
    Date:   Thu Jul 8 10:48:30 2021 -0500

        drm/i915/gem: Don't allow changing the VM on running contexts (v4)

this just completes the deed. I've tried to split out prep work for
more careful review as much as possible, this is what's left:

- get_ppgtt gets simplified since we don't need to grab a temporary
  reference - we can rely on the temporary reference for the gem_ctx
  while we inspect the vm. The new vm_id still needs a full
  i915_vm_open ofc. This also removes the final caller of context_get_vm_rcu

- A pile of selftests can now just look at ctx->vm instead of
  rcu_dereference_protected( , true) or similar things.

- All callers of i915_gem_context_vm also disappear.

- I've changed the hugepage selftest to set scrub_64K without any
  locking, because when we inspect that setting we're also not taking
  any locks either. It works because it's a selftests that's careful
  (single threaded gives you nice ordering) and not a live driver
  where races can happen from anywhere.

These can only be split up further if we have some intermediate state
with a bunch more rcu_dereference_protected(ctx->vm, true), just to
shut up lockdep and sparse.

The conversion to __rcu happened in

commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Oct 4 14:40:09 2019 +0100

    drm/i915: Move context management under GEM

Note that we're not breaking the actual bugfix in there: The real
bugfix is pushing the i915_vm_relase onto a separate worker, to avoid
locking inversion issues. The rcu conversion was just thrown in for
entertainment value on top (no vm lookup isn't even close to anything
that's a hotpath where removing the single spinlock can be measured).

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 53 ++-----------------
 drivers/gpu/drm/i915/gem/i915_gem_context.h   | 14 ++---
 .../gpu/drm/i915/gem/i915_gem_context_types.h |  2 +-
 .../gpu/drm/i915/gem/selftests/huge_pages.c   |  4 +-
 .../drm/i915/gem/selftests/i915_gem_context.c | 24 ++++-----
 drivers/gpu/drm/i915/i915_trace.h             |  2 +-
 drivers/gpu/drm/i915/selftests/i915_vma.c     |  2 +-
 7 files changed, 21 insertions(+), 80 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index fd24a1236682..2f3cc73d4710 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -735,44 +735,6 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
 	return ret;
 }
 
-static struct i915_address_space *
-context_get_vm_rcu(struct i915_gem_context *ctx)
-{
-	GEM_BUG_ON(!rcu_access_pointer(ctx->vm));
-
-	do {
-		struct i915_address_space *vm;
-
-		/*
-		 * We do not allow downgrading from full-ppgtt [to a shared
-		 * global gtt], so ctx->vm cannot become NULL.
-		 */
-		vm = rcu_dereference(ctx->vm);
-		if (!kref_get_unless_zero(&vm->ref))
-			continue;
-
-		/*
-		 * This ppgtt may have be reallocated between
-		 * the read and the kref, and reassigned to a third
-		 * context. In order to avoid inadvertent sharing
-		 * of this ppgtt with that third context (and not
-		 * src), we have to confirm that we have the same
-		 * ppgtt after passing through the strong memory
-		 * barrier implied by a successful
-		 * kref_get_unless_zero().
-		 *
-		 * Once we have acquired the current ppgtt of ctx,
-		 * we no longer care if it is released from ctx, as
-		 * it cannot be reallocated elsewhere.
-		 */
-
-		if (vm == rcu_access_pointer(ctx->vm))
-			return rcu_pointer_handoff(vm);
-
-		i915_vm_put(vm);
-	} while (1);
-}
-
 static int intel_context_set_gem(struct intel_context *ce,
 				 struct i915_gem_context *ctx,
 				 struct intel_sseu sseu)
@@ -1193,7 +1155,7 @@ static void context_close(struct i915_gem_context *ctx)
 
 	set_closed_name(ctx);
 
-	vm = i915_gem_context_vm(ctx);
+	vm = ctx->vm;
 	if (vm)
 		i915_vm_close(vm);
 
@@ -1350,7 +1312,7 @@ i915_gem_create_context(struct drm_i915_private *i915,
 		vm = &ppgtt->vm;
 	}
 	if (vm) {
-		RCU_INIT_POINTER(ctx->vm, i915_vm_open(vm));
+		ctx->vm = i915_vm_open(vm);
 
 		/* i915_vm_open() takes a reference */
 		i915_vm_put(vm);
@@ -1576,15 +1538,12 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	if (!i915_gem_context_is_full_ppgtt(ctx))
 		return -ENODEV;
 
-	rcu_read_lock();
-	vm = context_get_vm_rcu(ctx);
-	rcu_read_unlock();
-	if (!vm)
-		return -ENODEV;
+	vm = ctx->vm;
+	GEM_BUG_ON(!vm);
 
 	err = xa_alloc(&file_priv->vm_xa, &id, vm, xa_limit_32b, GFP_KERNEL);
 	if (err)
-		goto err_put;
+		return err;
 
 	i915_vm_open(vm);
 
@@ -1592,8 +1551,6 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	args->value = id;
 	args->size = 0;
 
-err_put:
-	i915_vm_put(vm);
 	return err;
 }
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 37536a260e6e..7696bc91647d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -148,17 +148,11 @@ static inline void i915_gem_context_put(struct i915_gem_context *ctx)
 	kref_put(&ctx->ref, i915_gem_context_release);
 }
 
-static inline struct i915_address_space *
-i915_gem_context_vm(struct i915_gem_context *ctx)
-{
-	return rcu_dereference_protected(ctx->vm, lockdep_is_held(&ctx->mutex));
-}
-
 static inline bool i915_gem_context_is_full_ppgtt(struct i915_gem_context *ctx)
 {
-	GEM_BUG_ON(!!rcu_access_pointer(ctx->vm) != HAS_FULL_PPGTT(ctx->i915));
+	GEM_BUG_ON(!!ctx->vm != HAS_FULL_PPGTT(ctx->i915));
 
-	return !!rcu_access_pointer(ctx->vm);
+	return !!ctx->vm;
 }
 
 static inline struct i915_address_space *
@@ -166,12 +160,10 @@ i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
 	struct i915_address_space *vm;
 
-	rcu_read_lock();
-	vm = rcu_dereference(ctx->vm);
+	vm = ctx->vm;
 	if (!vm)
 		vm = &ctx->i915->ggtt.vm;
 	vm = i915_vm_get(vm);
-	rcu_read_unlock();
 
 	return vm;
 }
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
index 94c03a97cb77..540ad16204a9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -262,7 +262,7 @@ struct i915_gem_context {
 	 * In other modes, this is a NULL pointer with the expectation that
 	 * the caller uses the shared global GTT.
 	 */
-	struct i915_address_space __rcu *vm;
+	struct i915_address_space *vm;
 
 	/**
 	 * @pid: process id of creator
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index 6c68fe26bb32..5d71626a1ee5 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1688,11 +1688,9 @@ int i915_gem_huge_page_live_selftests(struct drm_i915_private *i915)
 		goto out_file;
 	}
 
-	mutex_lock(&ctx->mutex);
-	vm = i915_gem_context_vm(ctx);
+	vm = ctx->vm;
 	if (vm)
 		WRITE_ONCE(vm->scrub_64K, true);
-	mutex_unlock(&ctx->mutex);
 
 	err = i915_subtests(tests, ctx);
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 0708b9cdeb9f..4370a90d8a50 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -27,12 +27,6 @@
 
 #define DW_PER_PAGE (PAGE_SIZE / sizeof(u32))
 
-static inline struct i915_address_space *ctx_vm(struct i915_gem_context *ctx)
-{
-	/* single threaded, private ctx */
-	return rcu_dereference_protected(ctx->vm, true);
-}
-
 static int live_nop_switch(void *arg)
 {
 	const unsigned int nctx = 1024;
@@ -813,7 +807,7 @@ static int igt_shared_ctx_exec(void *arg)
 			struct i915_gem_context *ctx;
 			struct intel_context *ce;
 
-			ctx = kernel_context(i915, ctx_vm(parent));
+			ctx = kernel_context(i915, parent->vm);
 			if (IS_ERR(ctx)) {
 				err = PTR_ERR(ctx);
 				goto out_test;
@@ -823,7 +817,7 @@ static int igt_shared_ctx_exec(void *arg)
 			GEM_BUG_ON(IS_ERR(ce));
 
 			if (!obj) {
-				obj = create_test_object(ctx_vm(parent),
+				obj = create_test_object(parent->vm,
 							 file, &objects);
 				if (IS_ERR(obj)) {
 					err = PTR_ERR(obj);
@@ -1380,7 +1374,7 @@ static int igt_ctx_readonly(void *arg)
 		goto out_file;
 	}
 
-	vm = ctx_vm(ctx) ?: &i915->ggtt.alias->vm;
+	vm = ctx->vm ?: &i915->ggtt.alias->vm;
 	if (!vm || !vm->has_read_only) {
 		err = 0;
 		goto out_file;
@@ -1499,7 +1493,7 @@ static int write_to_scratch(struct i915_gem_context *ctx,
 
 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
 
-	err = check_scratch(ctx_vm(ctx), offset);
+	err = check_scratch(ctx->vm, offset);
 	if (err)
 		return err;
 
@@ -1596,7 +1590,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
 
 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
 
-	err = check_scratch(ctx_vm(ctx), offset);
+	err = check_scratch(ctx->vm, offset);
 	if (err)
 		return err;
 
@@ -1739,7 +1733,7 @@ static int check_scratch_page(struct i915_gem_context *ctx, u32 *out)
 	u32 *vaddr;
 	int err = 0;
 
-	vm = ctx_vm(ctx);
+	vm = ctx->vm;
 	if (!vm)
 		return -ENODEV;
 
@@ -1801,7 +1795,7 @@ static int igt_vm_isolation(void *arg)
 	}
 
 	/* We can only test vm isolation, if the vm are distinct */
-	if (ctx_vm(ctx_a) == ctx_vm(ctx_b))
+	if (ctx_a->vm == ctx_b->vm)
 		goto out_file;
 
 	/* Read the initial state of the scratch page */
@@ -1813,8 +1807,8 @@ static int igt_vm_isolation(void *arg)
 	if (err)
 		goto out_file;
 
-	vm_total = ctx_vm(ctx_a)->total;
-	GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total);
+	vm_total = ctx_a->vm->total;
+	GEM_BUG_ON(ctx_b->vm->total != vm_total);
 
 	count = 0;
 	num_engines = 0;
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 806ad688274b..237e5061381b 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -1246,7 +1246,7 @@ DECLARE_EVENT_CLASS(i915_context,
 	TP_fast_assign(
 			__entry->dev = ctx->i915->drm.primary->index;
 			__entry->ctx = ctx;
-			__entry->vm = rcu_access_pointer(ctx->vm);
+			__entry->vm = ctx->vm;
 	),
 
 	TP_printk("dev=%u, ctx=%p, ctx_vm=%p",
diff --git a/drivers/gpu/drm/i915/selftests/i915_vma.c b/drivers/gpu/drm/i915/selftests/i915_vma.c
index 79ba72da0813..1f10fe36619b 100644
--- a/drivers/gpu/drm/i915/selftests/i915_vma.c
+++ b/drivers/gpu/drm/i915/selftests/i915_vma.c
@@ -39,7 +39,7 @@ static bool assert_vma(struct i915_vma *vma,
 {
 	bool ok = true;
 
-	if (vma->vm != rcu_access_pointer(ctx->vm)) {
+	if (vma->vm != ctx->vm) {
 		pr_err("VMA created with wrong VM\n");
 		ok = false;
 	}
-- 
2.32.0

[Intel-gfx] [PATCH v2 6/9] drm/i915: Drop __rcu from gem_context->vm

[Daniel Vetter]

It's been invariant since

    commit ccbc1b97948ab671335e950271e39766729736c3
    Author: Jason Ekstrand <jason@jlekstrand.net>
    Date:   Thu Jul 8 10:48:30 2021 -0500

        drm/i915/gem: Don't allow changing the VM on running contexts (v4)

this just completes the deed. I've tried to split out prep work for
more careful review as much as possible, this is what's left:

- get_ppgtt gets simplified since we don't need to grab a temporary
  reference - we can rely on the temporary reference for the gem_ctx
  while we inspect the vm. The new vm_id still needs a full
  i915_vm_open ofc. This also removes the final caller of context_get_vm_rcu

- A pile of selftests can now just look at ctx->vm instead of
  rcu_dereference_protected( , true) or similar things.

- All callers of i915_gem_context_vm also disappear.

- I've changed the hugepage selftest to set scrub_64K without any
  locking, because when we inspect that setting we're also not taking
  any locks either. It works because it's a selftests that's careful
  (single threaded gives you nice ordering) and not a live driver
  where races can happen from anywhere.

These can only be split up further if we have some intermediate state
with a bunch more rcu_dereference_protected(ctx->vm, true), just to
shut up lockdep and sparse.

The conversion to __rcu happened in

commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Oct 4 14:40:09 2019 +0100

    drm/i915: Move context management under GEM

Note that we're not breaking the actual bugfix in there: The real
bugfix is pushing the i915_vm_relase onto a separate worker, to avoid
locking inversion issues. The rcu conversion was just thrown in for
entertainment value on top (no vm lookup isn't even close to anything
that's a hotpath where removing the single spinlock can be measured).

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 53 ++-----------------
 drivers/gpu/drm/i915/gem/i915_gem_context.h   | 14 ++---
 .../gpu/drm/i915/gem/i915_gem_context_types.h |  2 +-
 .../gpu/drm/i915/gem/selftests/huge_pages.c   |  4 +-
 .../drm/i915/gem/selftests/i915_gem_context.c | 24 ++++-----
 drivers/gpu/drm/i915/i915_trace.h             |  2 +-
 drivers/gpu/drm/i915/selftests/i915_vma.c     |  2 +-
 7 files changed, 21 insertions(+), 80 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index fd24a1236682..2f3cc73d4710 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -735,44 +735,6 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
 	return ret;
 }
 
-static struct i915_address_space *
-context_get_vm_rcu(struct i915_gem_context *ctx)
-{
-	GEM_BUG_ON(!rcu_access_pointer(ctx->vm));
-
-	do {
-		struct i915_address_space *vm;
-
-		/*
-		 * We do not allow downgrading from full-ppgtt [to a shared
-		 * global gtt], so ctx->vm cannot become NULL.
-		 */
-		vm = rcu_dereference(ctx->vm);
-		if (!kref_get_unless_zero(&vm->ref))
-			continue;
-
-		/*
-		 * This ppgtt may have be reallocated between
-		 * the read and the kref, and reassigned to a third
-		 * context. In order to avoid inadvertent sharing
-		 * of this ppgtt with that third context (and not
-		 * src), we have to confirm that we have the same
-		 * ppgtt after passing through the strong memory
-		 * barrier implied by a successful
-		 * kref_get_unless_zero().
-		 *
-		 * Once we have acquired the current ppgtt of ctx,
-		 * we no longer care if it is released from ctx, as
-		 * it cannot be reallocated elsewhere.
-		 */
-
-		if (vm == rcu_access_pointer(ctx->vm))
-			return rcu_pointer_handoff(vm);
-
-		i915_vm_put(vm);
-	} while (1);
-}
-
 static int intel_context_set_gem(struct intel_context *ce,
 				 struct i915_gem_context *ctx,
 				 struct intel_sseu sseu)
@@ -1193,7 +1155,7 @@ static void context_close(struct i915_gem_context *ctx)
 
 	set_closed_name(ctx);
 
-	vm = i915_gem_context_vm(ctx);
+	vm = ctx->vm;
 	if (vm)
 		i915_vm_close(vm);
 
@@ -1350,7 +1312,7 @@ i915_gem_create_context(struct drm_i915_private *i915,
 		vm = &ppgtt->vm;
 	}
 	if (vm) {
-		RCU_INIT_POINTER(ctx->vm, i915_vm_open(vm));
+		ctx->vm = i915_vm_open(vm);
 
 		/* i915_vm_open() takes a reference */
 		i915_vm_put(vm);
@@ -1576,15 +1538,12 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	if (!i915_gem_context_is_full_ppgtt(ctx))
 		return -ENODEV;
 
-	rcu_read_lock();
-	vm = context_get_vm_rcu(ctx);
-	rcu_read_unlock();
-	if (!vm)
-		return -ENODEV;
+	vm = ctx->vm;
+	GEM_BUG_ON(!vm);
 
 	err = xa_alloc(&file_priv->vm_xa, &id, vm, xa_limit_32b, GFP_KERNEL);
 	if (err)
-		goto err_put;
+		return err;
 
 	i915_vm_open(vm);
 
@@ -1592,8 +1551,6 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	args->value = id;
 	args->size = 0;
 
-err_put:
-	i915_vm_put(vm);
 	return err;
 }
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index 37536a260e6e..7696bc91647d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -148,17 +148,11 @@ static inline void i915_gem_context_put(struct i915_gem_context *ctx)
 	kref_put(&ctx->ref, i915_gem_context_release);
 }
 
-static inline struct i915_address_space *
-i915_gem_context_vm(struct i915_gem_context *ctx)
-{
-	return rcu_dereference_protected(ctx->vm, lockdep_is_held(&ctx->mutex));
-}
-
 static inline bool i915_gem_context_is_full_ppgtt(struct i915_gem_context *ctx)
 {
-	GEM_BUG_ON(!!rcu_access_pointer(ctx->vm) != HAS_FULL_PPGTT(ctx->i915));
+	GEM_BUG_ON(!!ctx->vm != HAS_FULL_PPGTT(ctx->i915));
 
-	return !!rcu_access_pointer(ctx->vm);
+	return !!ctx->vm;
 }
 
 static inline struct i915_address_space *
@@ -166,12 +160,10 @@ i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
 	struct i915_address_space *vm;
 
-	rcu_read_lock();
-	vm = rcu_dereference(ctx->vm);
+	vm = ctx->vm;
 	if (!vm)
 		vm = &ctx->i915->ggtt.vm;
 	vm = i915_vm_get(vm);
-	rcu_read_unlock();
 
 	return vm;
 }
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
index 94c03a97cb77..540ad16204a9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -262,7 +262,7 @@ struct i915_gem_context {
 	 * In other modes, this is a NULL pointer with the expectation that
 	 * the caller uses the shared global GTT.
 	 */
-	struct i915_address_space __rcu *vm;
+	struct i915_address_space *vm;
 
 	/**
 	 * @pid: process id of creator
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index 6c68fe26bb32..5d71626a1ee5 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -1688,11 +1688,9 @@ int i915_gem_huge_page_live_selftests(struct drm_i915_private *i915)
 		goto out_file;
 	}
 
-	mutex_lock(&ctx->mutex);
-	vm = i915_gem_context_vm(ctx);
+	vm = ctx->vm;
 	if (vm)
 		WRITE_ONCE(vm->scrub_64K, true);
-	mutex_unlock(&ctx->mutex);
 
 	err = i915_subtests(tests, ctx);
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index 0708b9cdeb9f..4370a90d8a50 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -27,12 +27,6 @@
 
 #define DW_PER_PAGE (PAGE_SIZE / sizeof(u32))
 
-static inline struct i915_address_space *ctx_vm(struct i915_gem_context *ctx)
-{
-	/* single threaded, private ctx */
-	return rcu_dereference_protected(ctx->vm, true);
-}
-
 static int live_nop_switch(void *arg)
 {
 	const unsigned int nctx = 1024;
@@ -813,7 +807,7 @@ static int igt_shared_ctx_exec(void *arg)
 			struct i915_gem_context *ctx;
 			struct intel_context *ce;
 
-			ctx = kernel_context(i915, ctx_vm(parent));
+			ctx = kernel_context(i915, parent->vm);
 			if (IS_ERR(ctx)) {
 				err = PTR_ERR(ctx);
 				goto out_test;
@@ -823,7 +817,7 @@ static int igt_shared_ctx_exec(void *arg)
 			GEM_BUG_ON(IS_ERR(ce));
 
 			if (!obj) {
-				obj = create_test_object(ctx_vm(parent),
+				obj = create_test_object(parent->vm,
 							 file, &objects);
 				if (IS_ERR(obj)) {
 					err = PTR_ERR(obj);
@@ -1380,7 +1374,7 @@ static int igt_ctx_readonly(void *arg)
 		goto out_file;
 	}
 
-	vm = ctx_vm(ctx) ?: &i915->ggtt.alias->vm;
+	vm = ctx->vm ?: &i915->ggtt.alias->vm;
 	if (!vm || !vm->has_read_only) {
 		err = 0;
 		goto out_file;
@@ -1499,7 +1493,7 @@ static int write_to_scratch(struct i915_gem_context *ctx,
 
 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
 
-	err = check_scratch(ctx_vm(ctx), offset);
+	err = check_scratch(ctx->vm, offset);
 	if (err)
 		return err;
 
@@ -1596,7 +1590,7 @@ static int read_from_scratch(struct i915_gem_context *ctx,
 
 	GEM_BUG_ON(offset < I915_GTT_PAGE_SIZE);
 
-	err = check_scratch(ctx_vm(ctx), offset);
+	err = check_scratch(ctx->vm, offset);
 	if (err)
 		return err;
 
@@ -1739,7 +1733,7 @@ static int check_scratch_page(struct i915_gem_context *ctx, u32 *out)
 	u32 *vaddr;
 	int err = 0;
 
-	vm = ctx_vm(ctx);
+	vm = ctx->vm;
 	if (!vm)
 		return -ENODEV;
 
@@ -1801,7 +1795,7 @@ static int igt_vm_isolation(void *arg)
 	}
 
 	/* We can only test vm isolation, if the vm are distinct */
-	if (ctx_vm(ctx_a) == ctx_vm(ctx_b))
+	if (ctx_a->vm == ctx_b->vm)
 		goto out_file;
 
 	/* Read the initial state of the scratch page */
@@ -1813,8 +1807,8 @@ static int igt_vm_isolation(void *arg)
 	if (err)
 		goto out_file;
 
-	vm_total = ctx_vm(ctx_a)->total;
-	GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total);
+	vm_total = ctx_a->vm->total;
+	GEM_BUG_ON(ctx_b->vm->total != vm_total);
 
 	count = 0;
 	num_engines = 0;
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 806ad688274b..237e5061381b 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -1246,7 +1246,7 @@ DECLARE_EVENT_CLASS(i915_context,
 	TP_fast_assign(
 			__entry->dev = ctx->i915->drm.primary->index;
 			__entry->ctx = ctx;
-			__entry->vm = rcu_access_pointer(ctx->vm);
+			__entry->vm = ctx->vm;
 	),
 
 	TP_printk("dev=%u, ctx=%p, ctx_vm=%p",
diff --git a/drivers/gpu/drm/i915/selftests/i915_vma.c b/drivers/gpu/drm/i915/selftests/i915_vma.c
index 79ba72da0813..1f10fe36619b 100644
--- a/drivers/gpu/drm/i915/selftests/i915_vma.c
+++ b/drivers/gpu/drm/i915/selftests/i915_vma.c
@@ -39,7 +39,7 @@ static bool assert_vma(struct i915_vma *vma,
 {
 	bool ok = true;
 
-	if (vma->vm != rcu_access_pointer(ctx->vm)) {
+	if (vma->vm != ctx->vm) {
 		pr_err("VMA created with wrong VM\n");
 		ok = false;
 	}
-- 
2.32.0

[PATCH v2 7/9] drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups

[Daniel Vetter]

We don't need the absolute speed of rcu for this. And
i915_address_space in general dont need rcu protection anywhere else,
after we've made gem contexts and engines a lot more immutable.

Note that this semantically reverts

commit aabbe344dc3ca5f7d8263a02608ba6179e8a4499
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Aug 30 19:03:25 2019 +0100

    drm/i915: Use RCU for unlocked vm_idr lookup

except we have the conversion from idr to xarray in between.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/i915_drv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1488d166d91c..df2d723c894a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1880,11 +1880,11 @@ i915_gem_vm_lookup(struct drm_i915_file_private *file_priv, u32 id)
 {
 	struct i915_address_space *vm;
 
-	rcu_read_lock();
+	xa_lock(&file_priv->vm_xa);
 	vm = xa_load(&file_priv->vm_xa, id);
 	if (vm && !kref_get_unless_zero(&vm->ref))
 		vm = NULL;
-	rcu_read_unlock();
+	xa_unlock(&file_priv->vm_xa);
 
 	return vm;
 }
-- 
2.32.0

[Intel-gfx] [PATCH v2 7/9] drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups

[Daniel Vetter]

We don't need the absolute speed of rcu for this. And
i915_address_space in general dont need rcu protection anywhere else,
after we've made gem contexts and engines a lot more immutable.

Note that this semantically reverts

commit aabbe344dc3ca5f7d8263a02608ba6179e8a4499
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Aug 30 19:03:25 2019 +0100

    drm/i915: Use RCU for unlocked vm_idr lookup

except we have the conversion from idr to xarray in between.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/i915_drv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1488d166d91c..df2d723c894a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1880,11 +1880,11 @@ i915_gem_vm_lookup(struct drm_i915_file_private *file_priv, u32 id)
 {
 	struct i915_address_space *vm;
 
-	rcu_read_lock();
+	xa_lock(&file_priv->vm_xa);
 	vm = xa_load(&file_priv->vm_xa, id);
 	if (vm && !kref_get_unless_zero(&vm->ref))
 		vm = NULL;
-	rcu_read_unlock();
+	xa_unlock(&file_priv->vm_xa);
 
 	return vm;
 }
-- 
2.32.0

[PATCH v2 8/9] drm/i915: Stop rcu support for i915_address_space

[Daniel Vetter]

The full audit is quite a bit of work:

- i915_dpt has very simple lifetime (somehow we create a display pagetable vm
  per object, so its _very_ simple, there's only ever a single vma in there),
  and uses i915_vm_close(), which internally does a i915_vm_put(). No rcu.

  Aside: wtf is i915_dpt doing in the intel_display.c garbage collector as a new
  feature, instead of added as a separate file with some clean-ish interface.

  Also, i915_dpt unfortunately re-introduces some coding patterns from
  pre-dma_resv_lock conversion times.

- i915_gem_proto_ctx is fully refcounted and no rcu, all protected by
  fpriv->proto_context_lock.

- i915_gem_context is itself rcu protected, and that might leak to anything it
  points at. Before

	commit cf977e18610e66e48c31619e7e0cfa871be9eada
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Wed Dec 2 11:21:40 2020 +0000

	    drm/i915/gem: Spring clean debugfs

  and

	commit db80a1294c231b6ac725085f046bb2931e00c9db
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Mon Jan 18 11:08:54 2021 +0000

	    drm/i915/gem: Remove per-client stats from debugfs/i915_gem_objects

  we had a bunch of debugfs files that relied on rcu protecting everything, but
  those are gone now. The main one was removed even earlier with

  There doesn't seem to be anything left that's actually protecting
  stuff now that the ctx->vm itself is invariant. See

	commit ccbc1b97948ab671335e950271e39766729736c3
	Author: Jason Ekstrand <jason@jlekstrand.net>
	Date:   Thu Jul 8 10:48:30 2021 -0500

	    drm/i915/gem: Don't allow changing the VM on running contexts (v4)

  Note that we drop the vm refcount before the final release of the gem context
  refcount, so this is all very dangerous even without rcu. Note that aside from
  later on creating new engines (a defunct feature) and debug output we're never
  looked at gem_ctx->vm for anything functional, hence why this is ok.
  Fingers crossed.

  Preceeding patches removed all vestiges of rcu use from gem_ctx->vm
  derferencing to make it clear it's really not used.

  The gem_ctx->rcu protection was introduced in

	commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Fri Oct 4 14:40:09 2019 +0100

	    drm/i915: Move context management under GEM

  The commit message is somewhat entertaining because it fails to
  mention this fact completely, and compensates that by an in-commit
  changelog entry that claims that ctx->vm is protected by ctx->mutex.
  Which was the case _before_ this commit, but no longer after it.

- intel_context holds a full reference. Unfortunately intel_context is also rcu
  protected and the reference to the ->vm is dropped before the
  rcu barrier - only the kfree is delayed. So again we need to check
  whether that leaks anywhere on the intel_context->vm. RCU is only
  used to protect intel_context sitting on the breadcrumb lists, which
  don't look at the vm anywhere, so we are fine.

  Nothing else relies on rcu protection of intel_context and hence is
  fully protected by the kref refcount alone, which protects
  intel_context->vm in turn.

  The breadcrumbs rcu usage was added in

	commit c744d50363b714783bbc88d986cc16def13710f7
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Thu Nov 26 14:04:06 2020 +0000

	    drm/i915/gt: Split the breadcrumb spinlock between global and contexts

  its parent commit added the intel_context rcu protection:

	commit 14d1eaf08845c534963c83f754afe0cb14cb2512
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Thu Nov 26 14:04:05 2020 +0000

	    drm/i915/gt: Protect context lifetime with RCU

  given some credence to my claim that I've actually caught them all.

- drm_i915_gem_object's shares_resv_from pointer has a full refcount to the
  dma_resv, which is a sub-refcount that's released after the final
  i915_vm_put() has been called. Safe.

  Aside: Maybe we should have a struct dma_resv_shared which is just dma_resv +
  kref as a stand-alone thing. It's a pretty useful pattern which other drivers
  might want to copy.

  For a bit more context see

	commit 4d8151ae5329cf50781a02fd2298a909589a5bab
	Author: Thomas Hellström <thomas.hellstrom@linux.intel.com>
	Date:   Tue Jun 1 09:46:41 2021 +0200

	    drm/i915: Don't free shared locks while shared

- the fpriv->vm_xa was relying on rcu_read_lock for lookup, but that
  was updated in a prep patch too to just be a spinlock-protected
  lookup.

- intel_gt->vm is set at driver load in intel_gt_init() and released
  in intel_gt_driver_release(). There seems to be some issue that
  in some error paths this is called twice, but otherwise no rcu to be
  found anywhere. This was added in the below commit, which
  unfortunately doesn't explain why this complication exists.

	commit e6ba76480299a0d77c51d846f7467b1673aad25b
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Sat Dec 21 16:03:24 2019 +0000

	    drm/i915: Remove i915->kernel_context

  The proper fix most likely for this is to start using drmm_ at large
  scale, but that's also huge amounts of work.

- i915_vma->vm is some real pain, because rcu is rcu protected, at
  least in the vma lookup in the context lookup cache in
  eb_lookup_vma(). This was added in

	commit 4ff4b44cbb70c269259958cbcc48d7b8a2cb9ec8
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Fri Jun 16 15:05:16 2017 +0100

	    drm/i915: Store a direct lookup from object handle to vma

  This was changed to a radix tree from the hashtable in, but with the
  locking unchanged, in

	commit d1b48c1e7184d9bc4ae6d7f9fe2eed9efed11ffc
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Wed Aug 16 09:52:08 2017 +0100

	    drm/i915: Replace execbuf vma ht with an idr

  In

	commit 93159e12353c2a47e5576d642845a91fa00530bf
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Mon Mar 23 09:28:41 2020 +0000

	    drm/i915/gem: Avoid gem_context->mutex for simple vma lookup

  the locking was changed from dev->struct_mutex to rcu, which added
  the requirement to rcu protect i915_vma. Somehow this was missed in
  review (or I'm completely blind).

  Irrespective of all that the vma lookup cache rcu_read_lock grabs a
  full reference of the vma and the rcu doesn't leak further. So no
  impact on i915_address_space from that.

  I have not found any other rcu use for i915_vma, but given that it
  seems broken I also didn't bother to do a careful in-depth audit.

Alltogether there's nothing left in-tree anymore which requires that a
pointer deref to an i915_address_space is safe undre rcu_read_lock
only.

rcu protection of i915_address_space was introduced in

commit b32fa811156328aea5a3c2ff05cc096490382456
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Thu Jun 20 19:37:05 2019 +0100

    drm/i915/gtt: Defer address space cleanup to an RCU worker

by mixing up a bugfixing (i915_address_space needs to be released from
a worker) with enabling rcu support. The commit message also seems
somewhat confused, because it talks about cleanup of WC pages
requiring sleep, while the code and linked bugzilla are about a
requirement to take dev->struct_mutex (which yes sleeps but it's a
much more specific problem). Since final kref_put can be called from
pretty much anywhere (including hardirq context through the
scheduler's i915_active cleanup) we need a worker here. Hence that
part must be kept.

Ideally all these reclaim workers should have some kind of integration
with our shrinkers, but for some of these it's rather tricky. Anyway,
that's a preexisting condition in the codeebase that we wont fix in
this patch here.

We also remove the rcu_barrier in ggtt_cleanup_hw added in

commit 60a4233a4952729089e4df152e730f8f4d0e82ce
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Jul 29 14:24:12 2019 +0100

    drm/i915: Flush the i915_vm_release before ggtt shutdown

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gt/intel_ggtt.c | 1 -
 drivers/gpu/drm/i915/gt/intel_gtt.c  | 6 +++---
 drivers/gpu/drm/i915/gt/intel_gtt.h  | 2 +-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index de3ac58fceec..8d71f67926f1 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -727,7 +727,6 @@ static void ggtt_cleanup_hw(struct i915_ggtt *ggtt)
 
 	atomic_set(&ggtt->vm.open, 0);
 
-	rcu_barrier(); /* flush the RCU'ed__i915_vm_release */
 	flush_workqueue(ggtt->vm.i915->wq);
 
 	mutex_lock(&ggtt->vm.mutex);
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index e137dd32b5b8..a0c2b952aa57 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -155,7 +155,7 @@ void i915_vm_resv_release(struct kref *kref)
 static void __i915_vm_release(struct work_struct *work)
 {
 	struct i915_address_space *vm =
-		container_of(work, struct i915_address_space, rcu.work);
+		container_of(work, struct i915_address_space, release_work);
 
 	vm->cleanup(vm);
 	i915_address_space_fini(vm);
@@ -171,7 +171,7 @@ void i915_vm_release(struct kref *kref)
 	GEM_BUG_ON(i915_is_ggtt(vm));
 	trace_i915_ppgtt_release(vm);
 
-	queue_rcu_work(vm->i915->wq, &vm->rcu);
+	queue_work(vm->i915->wq, &vm->release_work);
 }
 
 void i915_address_space_init(struct i915_address_space *vm, int subclass)
@@ -185,7 +185,7 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 	if (!kref_read(&vm->resv_ref))
 		kref_init(&vm->resv_ref);
 
-	INIT_RCU_WORK(&vm->rcu, __i915_vm_release);
+	INIT_WORK(&vm->release_work, __i915_vm_release);
 	atomic_set(&vm->open, 1);
 
 	/*
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index bc7153018ebd..5b539bd7645d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -213,7 +213,7 @@ struct i915_vma_ops {
 
 struct i915_address_space {
 	struct kref ref;
-	struct rcu_work rcu;
+	struct work_struct release_work;
 
 	struct drm_mm mm;
 	struct intel_gt *gt;
-- 
2.32.0

[Intel-gfx] [PATCH v2 8/9] drm/i915: Stop rcu support for i915_address_space

[Daniel Vetter]

The full audit is quite a bit of work:

- i915_dpt has very simple lifetime (somehow we create a display pagetable vm
  per object, so its _very_ simple, there's only ever a single vma in there),
  and uses i915_vm_close(), which internally does a i915_vm_put(). No rcu.

  Aside: wtf is i915_dpt doing in the intel_display.c garbage collector as a new
  feature, instead of added as a separate file with some clean-ish interface.

  Also, i915_dpt unfortunately re-introduces some coding patterns from
  pre-dma_resv_lock conversion times.

- i915_gem_proto_ctx is fully refcounted and no rcu, all protected by
  fpriv->proto_context_lock.

- i915_gem_context is itself rcu protected, and that might leak to anything it
  points at. Before

	commit cf977e18610e66e48c31619e7e0cfa871be9eada
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Wed Dec 2 11:21:40 2020 +0000

	    drm/i915/gem: Spring clean debugfs

  and

	commit db80a1294c231b6ac725085f046bb2931e00c9db
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Mon Jan 18 11:08:54 2021 +0000

	    drm/i915/gem: Remove per-client stats from debugfs/i915_gem_objects

  we had a bunch of debugfs files that relied on rcu protecting everything, but
  those are gone now. The main one was removed even earlier with

  There doesn't seem to be anything left that's actually protecting
  stuff now that the ctx->vm itself is invariant. See

	commit ccbc1b97948ab671335e950271e39766729736c3
	Author: Jason Ekstrand <jason@jlekstrand.net>
	Date:   Thu Jul 8 10:48:30 2021 -0500

	    drm/i915/gem: Don't allow changing the VM on running contexts (v4)

  Note that we drop the vm refcount before the final release of the gem context
  refcount, so this is all very dangerous even without rcu. Note that aside from
  later on creating new engines (a defunct feature) and debug output we're never
  looked at gem_ctx->vm for anything functional, hence why this is ok.
  Fingers crossed.

  Preceeding patches removed all vestiges of rcu use from gem_ctx->vm
  derferencing to make it clear it's really not used.

  The gem_ctx->rcu protection was introduced in

	commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Fri Oct 4 14:40:09 2019 +0100

	    drm/i915: Move context management under GEM

  The commit message is somewhat entertaining because it fails to
  mention this fact completely, and compensates that by an in-commit
  changelog entry that claims that ctx->vm is protected by ctx->mutex.
  Which was the case _before_ this commit, but no longer after it.

- intel_context holds a full reference. Unfortunately intel_context is also rcu
  protected and the reference to the ->vm is dropped before the
  rcu barrier - only the kfree is delayed. So again we need to check
  whether that leaks anywhere on the intel_context->vm. RCU is only
  used to protect intel_context sitting on the breadcrumb lists, which
  don't look at the vm anywhere, so we are fine.

  Nothing else relies on rcu protection of intel_context and hence is
  fully protected by the kref refcount alone, which protects
  intel_context->vm in turn.

  The breadcrumbs rcu usage was added in

	commit c744d50363b714783bbc88d986cc16def13710f7
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Thu Nov 26 14:04:06 2020 +0000

	    drm/i915/gt: Split the breadcrumb spinlock between global and contexts

  its parent commit added the intel_context rcu protection:

	commit 14d1eaf08845c534963c83f754afe0cb14cb2512
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Thu Nov 26 14:04:05 2020 +0000

	    drm/i915/gt: Protect context lifetime with RCU

  given some credence to my claim that I've actually caught them all.

- drm_i915_gem_object's shares_resv_from pointer has a full refcount to the
  dma_resv, which is a sub-refcount that's released after the final
  i915_vm_put() has been called. Safe.

  Aside: Maybe we should have a struct dma_resv_shared which is just dma_resv +
  kref as a stand-alone thing. It's a pretty useful pattern which other drivers
  might want to copy.

  For a bit more context see

	commit 4d8151ae5329cf50781a02fd2298a909589a5bab
	Author: Thomas Hellström <thomas.hellstrom@linux.intel.com>
	Date:   Tue Jun 1 09:46:41 2021 +0200

	    drm/i915: Don't free shared locks while shared

- the fpriv->vm_xa was relying on rcu_read_lock for lookup, but that
  was updated in a prep patch too to just be a spinlock-protected
  lookup.

- intel_gt->vm is set at driver load in intel_gt_init() and released
  in intel_gt_driver_release(). There seems to be some issue that
  in some error paths this is called twice, but otherwise no rcu to be
  found anywhere. This was added in the below commit, which
  unfortunately doesn't explain why this complication exists.

	commit e6ba76480299a0d77c51d846f7467b1673aad25b
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Sat Dec 21 16:03:24 2019 +0000

	    drm/i915: Remove i915->kernel_context

  The proper fix most likely for this is to start using drmm_ at large
  scale, but that's also huge amounts of work.

- i915_vma->vm is some real pain, because rcu is rcu protected, at
  least in the vma lookup in the context lookup cache in
  eb_lookup_vma(). This was added in

	commit 4ff4b44cbb70c269259958cbcc48d7b8a2cb9ec8
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Fri Jun 16 15:05:16 2017 +0100

	    drm/i915: Store a direct lookup from object handle to vma

  This was changed to a radix tree from the hashtable in, but with the
  locking unchanged, in

	commit d1b48c1e7184d9bc4ae6d7f9fe2eed9efed11ffc
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Wed Aug 16 09:52:08 2017 +0100

	    drm/i915: Replace execbuf vma ht with an idr

  In

	commit 93159e12353c2a47e5576d642845a91fa00530bf
	Author: Chris Wilson <chris@chris-wilson.co.uk>
	Date:   Mon Mar 23 09:28:41 2020 +0000

	    drm/i915/gem: Avoid gem_context->mutex for simple vma lookup

  the locking was changed from dev->struct_mutex to rcu, which added
  the requirement to rcu protect i915_vma. Somehow this was missed in
  review (or I'm completely blind).

  Irrespective of all that the vma lookup cache rcu_read_lock grabs a
  full reference of the vma and the rcu doesn't leak further. So no
  impact on i915_address_space from that.

  I have not found any other rcu use for i915_vma, but given that it
  seems broken I also didn't bother to do a careful in-depth audit.

Alltogether there's nothing left in-tree anymore which requires that a
pointer deref to an i915_address_space is safe undre rcu_read_lock
only.

rcu protection of i915_address_space was introduced in

commit b32fa811156328aea5a3c2ff05cc096490382456
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Thu Jun 20 19:37:05 2019 +0100

    drm/i915/gtt: Defer address space cleanup to an RCU worker

by mixing up a bugfixing (i915_address_space needs to be released from
a worker) with enabling rcu support. The commit message also seems
somewhat confused, because it talks about cleanup of WC pages
requiring sleep, while the code and linked bugzilla are about a
requirement to take dev->struct_mutex (which yes sleeps but it's a
much more specific problem). Since final kref_put can be called from
pretty much anywhere (including hardirq context through the
scheduler's i915_active cleanup) we need a worker here. Hence that
part must be kept.

Ideally all these reclaim workers should have some kind of integration
with our shrinkers, but for some of these it's rather tricky. Anyway,
that's a preexisting condition in the codeebase that we wont fix in
this patch here.

We also remove the rcu_barrier in ggtt_cleanup_hw added in

commit 60a4233a4952729089e4df152e730f8f4d0e82ce
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Jul 29 14:24:12 2019 +0100

    drm/i915: Flush the i915_vm_release before ggtt shutdown

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gt/intel_ggtt.c | 1 -
 drivers/gpu/drm/i915/gt/intel_gtt.c  | 6 +++---
 drivers/gpu/drm/i915/gt/intel_gtt.h  | 2 +-
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index de3ac58fceec..8d71f67926f1 100644
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -727,7 +727,6 @@ static void ggtt_cleanup_hw(struct i915_ggtt *ggtt)
 
 	atomic_set(&ggtt->vm.open, 0);
 
-	rcu_barrier(); /* flush the RCU'ed__i915_vm_release */
 	flush_workqueue(ggtt->vm.i915->wq);
 
 	mutex_lock(&ggtt->vm.mutex);
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index e137dd32b5b8..a0c2b952aa57 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -155,7 +155,7 @@ void i915_vm_resv_release(struct kref *kref)
 static void __i915_vm_release(struct work_struct *work)
 {
 	struct i915_address_space *vm =
-		container_of(work, struct i915_address_space, rcu.work);
+		container_of(work, struct i915_address_space, release_work);
 
 	vm->cleanup(vm);
 	i915_address_space_fini(vm);
@@ -171,7 +171,7 @@ void i915_vm_release(struct kref *kref)
 	GEM_BUG_ON(i915_is_ggtt(vm));
 	trace_i915_ppgtt_release(vm);
 
-	queue_rcu_work(vm->i915->wq, &vm->rcu);
+	queue_work(vm->i915->wq, &vm->release_work);
 }
 
 void i915_address_space_init(struct i915_address_space *vm, int subclass)
@@ -185,7 +185,7 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 	if (!kref_read(&vm->resv_ref))
 		kref_init(&vm->resv_ref);
 
-	INIT_RCU_WORK(&vm->rcu, __i915_vm_release);
+	INIT_WORK(&vm->release_work, __i915_vm_release);
 	atomic_set(&vm->open, 1);
 
 	/*
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
index bc7153018ebd..5b539bd7645d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -213,7 +213,7 @@ struct i915_vma_ops {
 
 struct i915_address_space {
 	struct kref ref;
-	struct rcu_work rcu;
+	struct work_struct release_work;
 
 	struct drm_mm mm;
 	struct intel_gt *gt;
-- 
2.32.0

[PATCH v2 9/9] drm/i915: Split out intel_context_create_user

[Daniel Vetter]

There's quite a fundamental difference between userspace contexts, and
kernel contexts. Latter all share intel_gt->vm, former get their vm
from gem_ctx->vm (on full ppgtt at least).

By splitting context creation for userspace from kernel-internal ones
we can make this all a bit more strict and WARN_ON if there's a vm
already set in intel_context_set_gem().

All this is only possible because gem_ctx cannot chance their VM
anymore since

        commit ccbc1b97948ab671335e950271e39766729736c3
        Author: Jason Ekstrand <jason@jlekstrand.net>
        Date:   Thu Jul 8 10:48:30 2021 -0500

            drm/i915/gem: Don't allow changing the VM on running contexts (v4)

v2: I didn't take care of virtual engine creation and on top of that
collided pretty good with Matt's abstraction from

	commit 556120256ecd25aacea2c7e3ad11ec6584de7252
	Author: Matthew Brost <matthew.brost@intel.com>
	Date:   Mon Jul 26 17:23:16 2021 -0700

	    drm/i915/guc: GuC virtual engines

address this all by also splitting the new intel_engine_create_virtual
into a _user variant that doesn't set ce->vm.

Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 10 ++++-----
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  4 +++-
 .../gpu/drm/i915/gem/selftests/mock_context.c |  2 +-
 drivers/gpu/drm/i915/gt/intel_context.c       | 22 +++++++++++++++++--
 drivers/gpu/drm/i915/gt/intel_context.h       |  2 ++
 drivers/gpu/drm/i915/gt/intel_engine.h        |  4 ++++
 drivers/gpu/drm/i915/gt/intel_engine_cs.c     | 21 ++++++++++++++++--
 7 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 2f3cc73d4710..754b9b8d4981 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -746,7 +746,7 @@ static int intel_context_set_gem(struct intel_context *ce,
 
 	ce->ring_size = SZ_16K;
 
-	i915_vm_put(ce->vm);
+	WARN_ON(ce->vm);
 	ce->vm = i915_gem_context_get_eb_vm(ctx);
 
 	if (ctx->sched.priority >= I915_PRIORITY_NORMAL &&
@@ -856,7 +856,7 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx,
 		GEM_BUG_ON(engine->legacy_idx >= I915_NUM_ENGINES);
 		GEM_BUG_ON(e->engines[engine->legacy_idx]);
 
-		ce = intel_context_create(engine);
+		ce = intel_context_create_user(engine);
 		if (IS_ERR(ce)) {
 			err = ERR_CAST(ce);
 			goto free_engines;
@@ -897,12 +897,12 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
 
 		switch (pe[n].type) {
 		case I915_GEM_ENGINE_TYPE_PHYSICAL:
-			ce = intel_context_create(pe[n].engine);
+			ce = intel_context_create_user(pe[n].engine);
 			break;
 
 		case I915_GEM_ENGINE_TYPE_BALANCED:
-			ce = intel_engine_create_virtual(pe[n].siblings,
-							 pe[n].num_siblings);
+			ce = intel_engine_create_virtual_user(pe[n].siblings,
+							      pe[n].num_siblings);
 			break;
 
 		case I915_GEM_ENGINE_TYPE_INVALID:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index bdf2b5785a81..54de94433365 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -30,15 +30,17 @@
 
 struct eb_vma {
 	struct i915_vma *vma;
+	struct drm_i915_gem_object *obj;
 	unsigned int flags;
 
+	u32 handle;
+
 	/** This vma's place in the execbuf reservation list */
 	struct drm_i915_gem_exec_object2 *exec;
 	struct list_head bind_link;
 	struct list_head reloc_link;
 
 	struct hlist_node node;
-	u32 handle;
 };
 
 enum {
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
index fee070df1c97..e5efda1058a3 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
@@ -124,7 +124,7 @@ live_context_for_engine(struct intel_engine_cs *engine, struct file *file)
 		return ctx;
 	}
 
-	ce = intel_context_create(engine);
+	ce = intel_context_create_user(engine);
 	if (IS_ERR(ce)) {
 		__free_engines(engines, 0);
 		return ERR_CAST(ce);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 745e84c72c90..9e33efb594dd 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -34,6 +34,23 @@ void intel_context_free(struct intel_context *ce)
 	call_rcu(&ce->rcu, rcu_context_free);
 }
 
+/* for user contexts, callers must set ce->vm correctly */
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+
+	ce = intel_context_alloc();
+	if (!ce)
+		return ERR_PTR(-ENOMEM);
+
+	intel_context_init(ce, engine);
+
+	trace_intel_context_create(ce);
+	return ce;
+}
+
+/* for kernel-internal users only, sets ce->vm to intel_gt.vm */
 struct intel_context *
 intel_context_create(struct intel_engine_cs *engine)
 {
@@ -44,6 +61,8 @@ intel_context_create(struct intel_engine_cs *engine)
 		return ERR_PTR(-ENOMEM);
 
 	intel_context_init(ce, engine);
+	ce->vm = i915_vm_get(engine->gt->vm);
+
 	trace_intel_context_create(ce);
 	return ce;
 }
@@ -368,6 +387,7 @@ static int sw_fence_dummy_notify(struct i915_sw_fence *sf,
 	return NOTIFY_DONE;
 }
 
+/* callers must set ce->vm for user or kernel vm as needed */
 void
 intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 {
@@ -384,8 +404,6 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 
 	ewma_runtime_init(&ce->runtime.avg);
 
-	ce->vm = i915_vm_get(engine->gt->vm);
-
 	/* NB ce->signal_link/lock is used under RCU */
 	spin_lock_init(&ce->signal_lock);
 	INIT_LIST_HEAD(&ce->signals);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index c41098950746..a80018d53a36 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -34,6 +34,8 @@ void intel_context_fini(struct intel_context *ce);
 void i915_context_module_exit(void);
 int i915_context_module_init(void);
 
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine);
 struct intel_context *
 intel_context_create(struct intel_engine_cs *engine);
 
diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 87579affb952..6f945e60f6d6 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -279,6 +279,10 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
 	return intel_engine_has_preemption(engine);
 }
 
+struct intel_context *
+intel_engine_create_virtual_user(struct intel_engine_cs **siblings,
+				 unsigned int count);
+
 struct intel_context *
 intel_engine_create_virtual(struct intel_engine_cs **siblings,
 			    unsigned int count);
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 0d9105a31d84..34fe9dbfccba 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1879,9 +1879,10 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
 	return total;
 }
 
+/* for user contexts, callers must set ce->vm correctly */
 struct intel_context *
-intel_engine_create_virtual(struct intel_engine_cs **siblings,
-			    unsigned int count)
+intel_engine_create_virtual_user(struct intel_engine_cs **siblings,
+				 unsigned int count)
 {
 	if (count == 0)
 		return ERR_PTR(-EINVAL);
@@ -1893,6 +1894,22 @@ intel_engine_create_virtual(struct intel_engine_cs **siblings,
 	return siblings[0]->cops->create_virtual(siblings, count);
 }
 
+/* for kernel-internal users only, sets ce->vm to intel_gt.vm */
+struct intel_context *
+intel_engine_create_virtual(struct intel_engine_cs **siblings,
+			    unsigned int count)
+{
+	struct intel_context *ce;
+
+	ce = intel_engine_create_virtual_user(siblings, count);
+	if (IS_ERR(ce))
+		return ce;
+
+	ce->vm = i915_vm_get(siblings[0]->gt->vm);
+
+	return ce;
+}
+
 struct i915_request *
 intel_engine_execlist_find_hung_request(struct intel_engine_cs *engine)
 {
-- 
2.32.0

[Intel-gfx] [PATCH v2 9/9] drm/i915: Split out intel_context_create_user

[Daniel Vetter]

There's quite a fundamental difference between userspace contexts, and
kernel contexts. Latter all share intel_gt->vm, former get their vm
from gem_ctx->vm (on full ppgtt at least).

By splitting context creation for userspace from kernel-internal ones
we can make this all a bit more strict and WARN_ON if there's a vm
already set in intel_context_set_gem().

All this is only possible because gem_ctx cannot chance their VM
anymore since

        commit ccbc1b97948ab671335e950271e39766729736c3
        Author: Jason Ekstrand <jason@jlekstrand.net>
        Date:   Thu Jul 8 10:48:30 2021 -0500

            drm/i915/gem: Don't allow changing the VM on running contexts (v4)

v2: I didn't take care of virtual engine creation and on top of that
collided pretty good with Matt's abstraction from

	commit 556120256ecd25aacea2c7e3ad11ec6584de7252
	Author: Matthew Brost <matthew.brost@intel.com>
	Date:   Mon Jul 26 17:23:16 2021 -0700

	    drm/i915/guc: GuC virtual engines

address this all by also splitting the new intel_engine_create_virtual
into a _user variant that doesn't set ce->vm.

Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c   | 10 ++++-----
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  4 +++-
 .../gpu/drm/i915/gem/selftests/mock_context.c |  2 +-
 drivers/gpu/drm/i915/gt/intel_context.c       | 22 +++++++++++++++++--
 drivers/gpu/drm/i915/gt/intel_context.h       |  2 ++
 drivers/gpu/drm/i915/gt/intel_engine.h        |  4 ++++
 drivers/gpu/drm/i915/gt/intel_engine_cs.c     | 21 ++++++++++++++++--
 7 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 2f3cc73d4710..754b9b8d4981 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -746,7 +746,7 @@ static int intel_context_set_gem(struct intel_context *ce,
 
 	ce->ring_size = SZ_16K;
 
-	i915_vm_put(ce->vm);
+	WARN_ON(ce->vm);
 	ce->vm = i915_gem_context_get_eb_vm(ctx);
 
 	if (ctx->sched.priority >= I915_PRIORITY_NORMAL &&
@@ -856,7 +856,7 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx,
 		GEM_BUG_ON(engine->legacy_idx >= I915_NUM_ENGINES);
 		GEM_BUG_ON(e->engines[engine->legacy_idx]);
 
-		ce = intel_context_create(engine);
+		ce = intel_context_create_user(engine);
 		if (IS_ERR(ce)) {
 			err = ERR_CAST(ce);
 			goto free_engines;
@@ -897,12 +897,12 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
 
 		switch (pe[n].type) {
 		case I915_GEM_ENGINE_TYPE_PHYSICAL:
-			ce = intel_context_create(pe[n].engine);
+			ce = intel_context_create_user(pe[n].engine);
 			break;
 
 		case I915_GEM_ENGINE_TYPE_BALANCED:
-			ce = intel_engine_create_virtual(pe[n].siblings,
-							 pe[n].num_siblings);
+			ce = intel_engine_create_virtual_user(pe[n].siblings,
+							      pe[n].num_siblings);
 			break;
 
 		case I915_GEM_ENGINE_TYPE_INVALID:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index bdf2b5785a81..54de94433365 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -30,15 +30,17 @@
 
 struct eb_vma {
 	struct i915_vma *vma;
+	struct drm_i915_gem_object *obj;
 	unsigned int flags;
 
+	u32 handle;
+
 	/** This vma's place in the execbuf reservation list */
 	struct drm_i915_gem_exec_object2 *exec;
 	struct list_head bind_link;
 	struct list_head reloc_link;
 
 	struct hlist_node node;
-	u32 handle;
 };
 
 enum {
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
index fee070df1c97..e5efda1058a3 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
@@ -124,7 +124,7 @@ live_context_for_engine(struct intel_engine_cs *engine, struct file *file)
 		return ctx;
 	}
 
-	ce = intel_context_create(engine);
+	ce = intel_context_create_user(engine);
 	if (IS_ERR(ce)) {
 		__free_engines(engines, 0);
 		return ERR_CAST(ce);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 745e84c72c90..9e33efb594dd 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -34,6 +34,23 @@ void intel_context_free(struct intel_context *ce)
 	call_rcu(&ce->rcu, rcu_context_free);
 }
 
+/* for user contexts, callers must set ce->vm correctly */
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+
+	ce = intel_context_alloc();
+	if (!ce)
+		return ERR_PTR(-ENOMEM);
+
+	intel_context_init(ce, engine);
+
+	trace_intel_context_create(ce);
+	return ce;
+}
+
+/* for kernel-internal users only, sets ce->vm to intel_gt.vm */
 struct intel_context *
 intel_context_create(struct intel_engine_cs *engine)
 {
@@ -44,6 +61,8 @@ intel_context_create(struct intel_engine_cs *engine)
 		return ERR_PTR(-ENOMEM);
 
 	intel_context_init(ce, engine);
+	ce->vm = i915_vm_get(engine->gt->vm);
+
 	trace_intel_context_create(ce);
 	return ce;
 }
@@ -368,6 +387,7 @@ static int sw_fence_dummy_notify(struct i915_sw_fence *sf,
 	return NOTIFY_DONE;
 }
 
+/* callers must set ce->vm for user or kernel vm as needed */
 void
 intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 {
@@ -384,8 +404,6 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
 
 	ewma_runtime_init(&ce->runtime.avg);
 
-	ce->vm = i915_vm_get(engine->gt->vm);
-
 	/* NB ce->signal_link/lock is used under RCU */
 	spin_lock_init(&ce->signal_lock);
 	INIT_LIST_HEAD(&ce->signals);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index c41098950746..a80018d53a36 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -34,6 +34,8 @@ void intel_context_fini(struct intel_context *ce);
 void i915_context_module_exit(void);
 int i915_context_module_init(void);
 
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine);
 struct intel_context *
 intel_context_create(struct intel_engine_cs *engine);
 
diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 87579affb952..6f945e60f6d6 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -279,6 +279,10 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
 	return intel_engine_has_preemption(engine);
 }
 
+struct intel_context *
+intel_engine_create_virtual_user(struct intel_engine_cs **siblings,
+				 unsigned int count);
+
 struct intel_context *
 intel_engine_create_virtual(struct intel_engine_cs **siblings,
 			    unsigned int count);
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 0d9105a31d84..34fe9dbfccba 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1879,9 +1879,10 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
 	return total;
 }
 
+/* for user contexts, callers must set ce->vm correctly */
 struct intel_context *
-intel_engine_create_virtual(struct intel_engine_cs **siblings,
-			    unsigned int count)
+intel_engine_create_virtual_user(struct intel_engine_cs **siblings,
+				 unsigned int count)
 {
 	if (count == 0)
 		return ERR_PTR(-EINVAL);
@@ -1893,6 +1894,22 @@ intel_engine_create_virtual(struct intel_engine_cs **siblings,
 	return siblings[0]->cops->create_virtual(siblings, count);
 }
 
+/* for kernel-internal users only, sets ce->vm to intel_gt.vm */
+struct intel_context *
+intel_engine_create_virtual(struct intel_engine_cs **siblings,
+			    unsigned int count)
+{
+	struct intel_context *ce;
+
+	ce = intel_engine_create_virtual_user(siblings, count);
+	if (IS_ERR(ce))
+		return ce;
+
+	ce->vm = i915_vm_get(siblings[0]->gt->vm);
+
+	return ce;
+}
+
 struct i915_request *
 intel_engine_execlist_find_hung_request(struct intel_engine_cs *engine)
 {
-- 
2.32.0

[Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for remove rcu support from i915_address_space (rev3)

[Patchwork]

== Series Details ==

Series: remove rcu support from i915_address_space (rev3)
URL   : https://patchwork.freedesktop.org/series/93314/
State : warning

== Summary ==

$ dim checkpatch origin/drm-tip
caf6e7f302eb drm/i915: Drop code to handle set-vm races from execbuf
-:17: WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#17: 
References: ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")

-:17: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")'
#17: 
References: ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")

-:46: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 1 errors, 2 warnings, 0 checks, 12 lines checked
b7f87d0e543a drm/i915: Rename i915_gem_context_get_vm_rcu to i915_gem_context_get_eb_vm
-:148: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 0 errors, 1 warnings, 0 checks, 80 lines checked
3722c9bfcdf1 drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam
-:54: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 0 errors, 1 warnings, 0 checks, 23 lines checked
64d464c97eac drm/i915: Add i915_gem_context_is_full_ppgtt
-:105: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 0 errors, 1 warnings, 0 checks, 53 lines checked
c09e5c29dada drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem
-:12: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")'
#12: 
commit ccbc1b97948ab671335e950271e39766729736c3

-:61: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 1 errors, 1 warnings, 0 checks, 18 lines checked
07447b03edbd drm/i915: Drop __rcu from gem_context->vm
-:11: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")'
#11: 
    commit ccbc1b97948ab671335e950271e39766729736c3

-:23: WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#23: 
  i915_vm_open ofc. This also removes the final caller of context_get_vm_rcu

-:42: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit a4e7ccdac38e ("drm/i915: Move context management under GEM")'
#42: 
commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1

-:345: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 2 errors, 2 warnings, 0 checks, 232 lines checked
a10bb14f41b0 drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups
-:15: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit aabbe344dc3c ("drm/i915: Use RCU for unlocked vm_idr lookup")'
#15: 
commit aabbe344dc3ca5f7d8263a02608ba6179e8a4499

-:52: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 1 errors, 1 warnings, 0 checks, 13 lines checked
79ceebe3d9e5 drm/i915: Stop rcu support for i915_address_space
-:11: WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#11: 
- i915_dpt has very simple lifetime (somehow we create a display pagetable vm

-:27: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit cf977e18610e ("drm/i915/gem: Spring clean debugfs")'
#27: 
	commit cf977e18610e66e48c31619e7e0cfa871be9eada

-:35: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit db80a1294c23 ("drm/i915/gem: Remove per-client stats from debugfs/i915_gem_objects")'
#35: 
	commit db80a1294c231b6ac725085f046bb2931e00c9db

-:47: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")'
#47: 
	commit ccbc1b97948ab671335e950271e39766729736c3

-:59: WARNING:TYPO_SPELLING: 'Preceeding' may be misspelled - perhaps 'Preceding'?
#59: 
  Preceeding patches removed all vestiges of rcu use from gem_ctx->vm
  ^^^^^^^^^^

-:64: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit a4e7ccdac38e ("drm/i915: Move context management under GEM")'
#64: 
	commit a4e7ccdac38ec8335d9e4e2656c1a041c77feae1

-:88: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit c744d50363b7 ("drm/i915/gt: Split the breadcrumb spinlock between global and contexts")'
#88: 
	commit c744d50363b714783bbc88d986cc16def13710f7

-:94: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit added5fce61e ("ARM: mxs_defconfig: add CONFIG_USB_PHY")'
#94: 
  its parent commit added the intel_context rcu protection:

-:96: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 14d1eaf08845 ("drm/i915/gt: Protect context lifetime with RCU")'
#96: 
	commit 14d1eaf08845c534963c83f754afe0cb14cb2512

-:114: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 4d8151ae5329 ("drm/i915: Don't free shared locks while shared")'
#114: 
	commit 4d8151ae5329cf50781a02fd2298a909589a5bab

-:130: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit e6ba76480299 ("drm/i915: Remove i915->kernel_context")'
#130: 
	commit e6ba76480299a0d77c51d846f7467b1673aad25b

-:143: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 4ff4b44cbb70 ("drm/i915: Store a direct lookup from object handle to vma")'
#143: 
	commit 4ff4b44cbb70c269259958cbcc48d7b8a2cb9ec8

-:152: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit d1b48c1e7184 ("drm/i915: Replace execbuf vma ht with an idr")'
#152: 
	commit d1b48c1e7184d9bc4ae6d7f9fe2eed9efed11ffc

-:160: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 93159e12353c ("drm/i915/gem: Avoid gem_context->mutex for simple vma lookup")'
#160: 
	commit 93159e12353c2a47e5576d642845a91fa00530bf

-:183: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit b32fa8111563 ("drm/i915/gtt: Defer address space cleanup to an RCU worker")'
#183: 
commit b32fa811156328aea5a3c2ff05cc096490382456

-:201: WARNING:TYPO_SPELLING: 'wont' may be misspelled - perhaps 'won't'?
#201: 
that's a preexisting condition in the codeebase that we wont fix in
                                                        ^^^^

-:206: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 60a4233a4952 ("drm/i915: Flush the i915_vm_release before ggtt shutdown")'
#206: 
commit 60a4233a4952729089e4df152e730f8f4d0e82ce

-:279: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 14 errors, 4 warnings, 0 checks, 39 lines checked
9b1a3e40d5cd drm/i915: Split out intel_context_create_user
-:20: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit ccbc1b97948a ("drm/i915/gem: Don't allow changing the VM on running contexts (v4)")'
#20: 
        commit ccbc1b97948ab671335e950271e39766729736c3

-:29: ERROR:GIT_COMMIT_ID: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 556120256ecd ("drm/i915/guc: GuC virtual engines")'
#29: 
	commit 556120256ecd25aacea2c7e3ad11ec6584de7252

-:248: WARNING:FROM_SIGN_OFF_MISMATCH: From:/Signed-off-by: email address mismatch: 'From: Daniel Vetter <daniel.vetter@ffwll.ch>' != 'Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>'

total: 2 errors, 1 warnings, 0 checks, 155 lines checked

[Intel-gfx] ✗ Fi.CI.SPARSE: warning for remove rcu support from i915_address_space (rev3)

[Patchwork]

== Series Details ==

Series: remove rcu support from i915_address_space (rev3)
URL   : https://patchwork.freedesktop.org/series/93314/
State : warning

== Summary ==

$ dim sparse --fast origin/drm-tip
Sparse version: v0.6.2
Fast mode used, each commit won't be checked separately.
-drivers/gpu/drm/i915/gem/i915_gem_context.c:1364:34:    expected struct i915_address_space *vm
-drivers/gpu/drm/i915/gem/i915_gem_context.c:1364:34:    got struct i915_address_space [noderef] __rcu *vm
-drivers/gpu/drm/i915/gem/i915_gem_context.c:1364:34: warning: incorrect type in argument 1 (different address spaces)
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:43:25:    expected struct i915_address_space [noderef] __rcu *vm
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:43:25:    got struct i915_address_space *
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:43:25: warning: incorrect type in assignment (different address spaces)
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:60:34:    expected struct i915_address_space *vm
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:60:34:    got struct i915_address_space [noderef] __rcu *vm
-drivers/gpu/drm/i915/gem/selftests/mock_context.c:60:34: warning: incorrect type in argument 1 (different address spaces)

[Intel-gfx] ✗ Fi.CI.BAT: failure for remove rcu support from i915_address_space (rev3)

[Patchwork]

[-- Attachment #1: Type: text/plain, Size: 14049 bytes --]

== Series Details ==

Series: remove rcu support from i915_address_space (rev3)
URL   : https://patchwork.freedesktop.org/series/93314/
State : failure

== Summary ==

CI Bug Log - changes from CI_DRM_10445 -> Patchwork_20768
====================================================

Summary
-------

  **FAILURE**

  Serious unknown changes coming with Patchwork_20768 absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_20768, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/index.html

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_20768:

### IGT changes ###

#### Possible regressions ####

  * igt@i915_selftest@live@execlists:
    - fi-cfl-8109u:       [PASS][1] -> [INCOMPLETE][2]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-cfl-8109u/igt@i915_selftest@live@execlists.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-8109u/igt@i915_selftest@live@execlists.html
    - fi-bsw-nick:        [PASS][3] -> [DMESG-FAIL][4]
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-bsw-nick/igt@i915_selftest@live@execlists.html
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bsw-nick/igt@i915_selftest@live@execlists.html
    - fi-glk-dsi:         [PASS][5] -> [DMESG-FAIL][6]
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-glk-dsi/igt@i915_selftest@live@execlists.html
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-glk-dsi/igt@i915_selftest@live@execlists.html
    - fi-kbl-x1275:       [PASS][7] -> [DMESG-FAIL][8]
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-kbl-x1275/igt@i915_selftest@live@execlists.html
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-x1275/igt@i915_selftest@live@execlists.html
    - fi-cfl-8700k:       [PASS][9] -> [DMESG-FAIL][10]
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-cfl-8700k/igt@i915_selftest@live@execlists.html
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-8700k/igt@i915_selftest@live@execlists.html
    - fi-tgl-u2:          [PASS][11] -> [INCOMPLETE][12]
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-tgl-u2/igt@i915_selftest@live@execlists.html
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-u2/igt@i915_selftest@live@execlists.html
    - fi-skl-guc:         [PASS][13] -> [DMESG-FAIL][14]
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-skl-guc/igt@i915_selftest@live@execlists.html
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-skl-guc/igt@i915_selftest@live@execlists.html
    - fi-skl-6700k2:      [PASS][15] -> [DMESG-FAIL][16]
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-skl-6700k2/igt@i915_selftest@live@execlists.html
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-skl-6700k2/igt@i915_selftest@live@execlists.html
    - fi-cfl-guc:         [PASS][17] -> [DMESG-FAIL][18]
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-cfl-guc/igt@i915_selftest@live@execlists.html
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-guc/igt@i915_selftest@live@execlists.html
    - fi-bxt-dsi:         [PASS][19] -> [DMESG-FAIL][20]
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-bxt-dsi/igt@i915_selftest@live@execlists.html
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bxt-dsi/igt@i915_selftest@live@execlists.html
    - fi-tgl-1115g4:      [PASS][21] -> [DMESG-FAIL][22]
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-tgl-1115g4/igt@i915_selftest@live@execlists.html
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-1115g4/igt@i915_selftest@live@execlists.html
    - fi-cml-u2:          [PASS][23] -> [DMESG-FAIL][24]
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-cml-u2/igt@i915_selftest@live@execlists.html
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cml-u2/igt@i915_selftest@live@execlists.html
    - fi-kbl-guc:         [PASS][25] -> [DMESG-FAIL][26]
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-kbl-guc/igt@i915_selftest@live@execlists.html
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-guc/igt@i915_selftest@live@execlists.html
    - fi-kbl-7500u:       [PASS][27] -> [DMESG-FAIL][28]
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-kbl-7500u/igt@i915_selftest@live@execlists.html
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-7500u/igt@i915_selftest@live@execlists.html

  * igt@i915_selftest@live@requests:
    - fi-pnv-d510:        [PASS][29] -> [DMESG-FAIL][30]
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-pnv-d510/igt@i915_selftest@live@requests.html
   [30]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-pnv-d510/igt@i915_selftest@live@requests.html

  
#### Suppressed ####

  The following results come from untrusted machines, tests, or statuses.
  They do not affect the overall result.

  * igt@i915_selftest@live@execlists:
    - {fi-ehl-2}:         [PASS][31] -> [DMESG-FAIL][32]
   [31]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-ehl-2/igt@i915_selftest@live@execlists.html
   [32]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-ehl-2/igt@i915_selftest@live@execlists.html
    - {fi-tgl-dsi}:       [PASS][33] -> [INCOMPLETE][34]
   [33]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-tgl-dsi/igt@i915_selftest@live@execlists.html
   [34]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-dsi/igt@i915_selftest@live@execlists.html

  * igt@runner@aborted:
    - {fi-ehl-2}:         NOTRUN -> [FAIL][35]
   [35]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-ehl-2/igt@runner@aborted.html

  
Known issues
------------

  Here are the changes found in Patchwork_20768 that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@i915_selftest@live@execlists:
    - fi-bsw-kefka:       [PASS][36] -> [INCOMPLETE][37] ([i915#2782] / [i915#2940])
   [36]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-bsw-kefka/igt@i915_selftest@live@execlists.html
   [37]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bsw-kefka/igt@i915_selftest@live@execlists.html
    - fi-kbl-7567u:       [PASS][38] -> [INCOMPLETE][39] ([i915#2782] / [i915#794])
   [38]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-kbl-7567u/igt@i915_selftest@live@execlists.html
   [39]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-7567u/igt@i915_selftest@live@execlists.html
    - fi-icl-y:           [PASS][40] -> [INCOMPLETE][41] ([i915#2782])
   [40]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-icl-y/igt@i915_selftest@live@execlists.html
   [41]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-icl-y/igt@i915_selftest@live@execlists.html
    - fi-kbl-soraka:      [PASS][42] -> [INCOMPLETE][43] ([i915#2782] / [i915#794])
   [42]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-kbl-soraka/igt@i915_selftest@live@execlists.html
   [43]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-soraka/igt@i915_selftest@live@execlists.html

  * igt@runner@aborted:
    - fi-pnv-d510:        NOTRUN -> [FAIL][44] ([fdo#109271] / [i915#2403] / [i915#2505])
   [44]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-pnv-d510/igt@runner@aborted.html
    - fi-kbl-x1275:       NOTRUN -> [FAIL][45] ([i915#1436] / [i915#2426] / [i915#3363])
   [45]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-x1275/igt@runner@aborted.html
    - fi-bsw-kefka:       NOTRUN -> [FAIL][46] ([fdo#109271] / [i915#1436] / [i915#3690])
   [46]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bsw-kefka/igt@runner@aborted.html
    - fi-cfl-8700k:       NOTRUN -> [FAIL][47] ([i915#2426] / [i915#3363])
   [47]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-8700k/igt@runner@aborted.html
    - fi-cfl-8109u:       NOTRUN -> [FAIL][48] ([i915#2426] / [i915#3363])
   [48]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-8109u/igt@runner@aborted.html
    - fi-glk-dsi:         NOTRUN -> [FAIL][49] ([i915#2426] / [i915#3363] / [k.org#202321])
   [49]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-glk-dsi/igt@runner@aborted.html
    - fi-bsw-nick:        NOTRUN -> [FAIL][50] ([fdo#109271] / [i915#1436] / [i915#3690])
   [50]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bsw-nick/igt@runner@aborted.html
    - fi-kbl-soraka:      NOTRUN -> [FAIL][51] ([i915#1436] / [i915#2426] / [i915#3363])
   [51]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-soraka/igt@runner@aborted.html
    - fi-kbl-7500u:       NOTRUN -> [FAIL][52] ([i915#1436] / [i915#2426] / [i915#3363])
   [52]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-7500u/igt@runner@aborted.html
    - fi-kbl-guc:         NOTRUN -> [FAIL][53] ([i915#1436] / [i915#2426] / [i915#3363])
   [53]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-guc/igt@runner@aborted.html
    - fi-cml-u2:          NOTRUN -> [FAIL][54] ([i915#2082] / [i915#2426] / [i915#3363] / [i915#3462])
   [54]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cml-u2/igt@runner@aborted.html
    - fi-bxt-dsi:         NOTRUN -> [FAIL][55] ([i915#2426] / [i915#3363])
   [55]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-bxt-dsi/igt@runner@aborted.html
    - fi-tgl-1115g4:      NOTRUN -> [FAIL][56] ([i915#1436] / [i915#2966] / [i915#3690])
   [56]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-1115g4/igt@runner@aborted.html
    - fi-cfl-guc:         NOTRUN -> [FAIL][57] ([i915#2426] / [i915#3363])
   [57]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-cfl-guc/igt@runner@aborted.html
    - fi-icl-y:           NOTRUN -> [FAIL][58] ([i915#2782] / [i915#3690])
   [58]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-icl-y/igt@runner@aborted.html
    - fi-kbl-7567u:       NOTRUN -> [FAIL][59] ([i915#1436] / [i915#2426] / [i915#3363])
   [59]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-kbl-7567u/igt@runner@aborted.html
    - fi-skl-guc:         NOTRUN -> [FAIL][60] ([i915#1436] / [i915#2426] / [i915#3363])
   [60]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-skl-guc/igt@runner@aborted.html
    - fi-skl-6700k2:      NOTRUN -> [FAIL][61] ([i915#1436] / [i915#2426] / [i915#3363])
   [61]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-skl-6700k2/igt@runner@aborted.html
    - fi-tgl-u2:          NOTRUN -> [FAIL][62] ([i915#1436] / [i915#2966] / [i915#3690])
   [62]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-u2/igt@runner@aborted.html

  
#### Possible fixes ####

  * igt@gem_exec_suspend@basic-s0:
    - fi-tgl-1115g4:      [FAIL][63] ([i915#1888]) -> [PASS][64]
   [63]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10445/fi-tgl-1115g4/igt@gem_exec_suspend@basic-s0.html
   [64]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/fi-tgl-1115g4/igt@gem_exec_suspend@basic-s0.html

  
  {name}: This element is suppressed. This means it is ignored when computing
          the status of the difference (SUCCESS, WARNING, or FAILURE).

  [fdo#109271]: https://bugs.freedesktop.org/show_bug.cgi?id=109271
  [i915#1436]: https://gitlab.freedesktop.org/drm/intel/issues/1436
  [i915#1888]: https://gitlab.freedesktop.org/drm/intel/issues/1888
  [i915#2082]: https://gitlab.freedesktop.org/drm/intel/issues/2082
  [i915#2403]: https://gitlab.freedesktop.org/drm/intel/issues/2403
  [i915#2426]: https://gitlab.freedesktop.org/drm/intel/issues/2426
  [i915#2505]: https://gitlab.freedesktop.org/drm/intel/issues/2505
  [i915#2782]: https://gitlab.freedesktop.org/drm/intel/issues/2782
  [i915#2932]: https://gitlab.freedesktop.org/drm/intel/issues/2932
  [i915#2940]: https://gitlab.freedesktop.org/drm/intel/issues/2940
  [i915#2966]: https://gitlab.freedesktop.org/drm/intel/issues/2966
  [i915#3363]: https://gitlab.freedesktop.org/drm/intel/issues/3363
  [i915#3462]: https://gitlab.freedesktop.org/drm/intel/issues/3462
  [i915#3690]: https://gitlab.freedesktop.org/drm/intel/issues/3690
  [i915#794]: https://gitlab.freedesktop.org/drm/intel/issues/794
  [k.org#202321]: https://bugzilla.kernel.org/show_bug.cgi?id=202321


Participating hosts (35 -> 33)
------------------------------

  Missing    (2): fi-bsw-cyan fi-bdw-samus 


Build changes
-------------

  * Linux: CI_DRM_10445 -> Patchwork_20768

  CI-20190529: 20190529
  CI_DRM_10445: ad27c4ace81558b6a9c3208913e222cfd0218503 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_6159: 6135b9cc319ed965e3aafb5b2ae2abf4762a06b2 @ https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
  Patchwork_20768: 9b1a3e40d5cd6670e35d6a378b7c72e2f98e096b @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

9b1a3e40d5cd drm/i915: Split out intel_context_create_user
79ceebe3d9e5 drm/i915: Stop rcu support for i915_address_space
a10bb14f41b0 drm/i915: use xa_lock/unlock for fpriv->vm_xa lookups
07447b03edbd drm/i915: Drop __rcu from gem_context->vm
c09e5c29dada drm/i915: Use i915_gem_context_get_eb_vm in intel_context_set_gem
64d464c97eac drm/i915: Add i915_gem_context_is_full_ppgtt
3722c9bfcdf1 drm/i915: Use i915_gem_context_get_eb_vm in ctx_getparam
b7f87d0e543a drm/i915: Rename i915_gem_context_get_vm_rcu to i915_gem_context_get_eb_vm
caf6e7f302eb drm/i915: Drop code to handle set-vm races from execbuf

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_20768/index.html

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