[PATCH v3] drm/xe/eudebug: implement userptr_vma access

[Andrzej Hajda]

Debugger needs to read/write program's vmas including userptr_vma.

v2: pin pages vs notifier, move to vm.c (Matthew)
v3: use access_process_vm core helper

Signed-off-by: Andrzej Hajda <andrzej.hajda at intel.com>
---
 drivers/gpu/drm/xe/xe_eudebug.c |  2 +-
 drivers/gpu/drm/xe/xe_vm.c      | 12 ++++++++++++
 drivers/gpu/drm/xe/xe_vm.h      |  3 +++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_eudebug.c b/drivers/gpu/drm/xe/xe_eudebug.c
index 7e62b0ffca83..bc0b32c47ed5 100644
--- a/drivers/gpu/drm/xe/xe_eudebug.c
+++ b/drivers/gpu/drm/xe/xe_eudebug.c
@@ -3392,7 +3392,7 @@ static int xe_eudebug_vma_access(struct xe_vma *vma, u64 offset,
 	if (bo)
 		return xe_eudebug_bovma_access(bo, offset, buf, bytes, write);
 
-	return -EOPNOTSUPP;
+	return xe_vm_userptr_access(to_userptr_vma(vma), offset, buf, bytes, write);
 }
 
 static int xe_eudebug_vm_access(struct xe_vm *vm, u64 offset,
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index ec4dd2c611d3..f46c8fc05218 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3607,3 +3607,15 @@ void xe_vm_snapshot_free(struct xe_vm_snapshot *snap)
 	}
 	kvfree(snap);
 }
+
+int xe_vm_userptr_access(struct xe_userptr_vma *uvma, u64 offset,
+			 void *buf, u64 len, bool write)
+{
+	struct mm_struct *mm = uvma->userptr.notifier.mm;
+	unsigned long addr = uvma->vma.gpuva.gem.offset;
+
+	if (!mm || !mm->owner)
+		return -EINVAL;
+
+	return access_process_vm(mm->owner, addr, buf, len, write ? FOLL_WRITE : 0);
+}
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index c864dba35e1d..165eab494d59 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/drivers/gpu/drm/xe/xe_vm.h
@@ -281,3 +281,6 @@ struct xe_vm_snapshot *xe_vm_snapshot_capture(struct xe_vm *vm);
 void xe_vm_snapshot_capture_delayed(struct xe_vm_snapshot *snap);
 void xe_vm_snapshot_print(struct xe_vm_snapshot *snap, struct drm_printer *p);
 void xe_vm_snapshot_free(struct xe_vm_snapshot *snap);
+
+int xe_vm_userptr_access(struct xe_userptr_vma *uvma, u64 offset,
+			 void *buf, u64 len, bool write);
-- 
2.34.1