drm/xe/vm: fix double list add

It looks like the driver only wants to track one vma for each external
object per vm. However it looks like bo_has_vm_references_locked() will
ignore any vma that is marked as vma->destroyed (not actually destroyed
yet). If we then mark our externally tracked vma as destroyed and then
create a new vma for the same object and vm, we can have two externally
tracked vma for the same object and vm. When the destroy actually
happens it tries to move the external tracking to a different vma, but
in this case it is already being tracked, leading to double list add
errors. It should be safe to simply drop the destroyed check in
bo_has_vm_references(), since the actual destroy will switch the
external tracking to the next available vma.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/290
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index ffa102870d1fd1cdf0941297a65da090adb2bf7c..5af370640fb15894df445a11fa5211c56ac3ae0e 100644 (file)
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -964,7 +964,7 @@ bo_has_vm_references_locked(struct xe_bo *bo, struct xe_vm *vm,
        struct xe_vma *vma;
 
        list_for_each_entry(vma, &bo->vmas, bo_link) {
-               if (vma != ignore && vma->vm == vm && !vma->destroyed)
+               if (vma != ignore && vma->vm == vm)
                        return vma;
        }