For preempt_fence mode VM's we're rejecting eviction of
shared bos during VM_BIND. However, since we do this in the
move() callback, we're getting an eviction failure warning from
TTM. The TTM callback intended for these things is
eviction_valuable().
However, the latter doesn't pass in the struct ttm_operation_ctx
needed to determine whether the caller needs this.
Instead, attach the needed information to the vm under the
vm->resv, until we've been able to update TTM to provide the
needed information. And add sufficient lockdep checks to prevent
misuse and races.
v2:
- Fix a copy-paste error in xe_vm_clear_validating()
v3:
- Fix kerneldoc errors.
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Fixes:
0af944f0e308 ("drm/xe: Reject BO eviction if BO is bound to current VM")
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250528164105.234718-1-thomas.hellstrom@linux.intel.com
(cherry picked from commit
9d5558649f68e2e84a87a909631b30e15ca0f8ec)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
goto out;
}
- /* Reject BO eviction if BO is bound to current VM. */
- if (evict && ctx->resv) {
- struct drm_gpuvm_bo *vm_bo;
-
- drm_gem_for_each_gpuvm_bo(vm_bo, &bo->ttm.base) {
- struct xe_vm *vm = gpuvm_to_vm(vm_bo->vm);
-
- if (xe_vm_resv(vm) == ctx->resv &&
- xe_vm_in_preempt_fence_mode(vm)) {
- ret = -EBUSY;
- goto out;
- }
- }
- }
-
/*
* Failed multi-hop where the old_mem is still marked as
* TTM_PL_FLAG_TEMPORARY, should just be a dummy move.
return lret;
}
+static bool
+xe_bo_eviction_valuable(struct ttm_buffer_object *bo, const struct ttm_place *place)
+{
+ struct drm_gpuvm_bo *vm_bo;
+
+ if (!ttm_bo_eviction_valuable(bo, place))
+ return false;
+
+ if (!xe_bo_is_xe_bo(bo))
+ return true;
+
+ drm_gem_for_each_gpuvm_bo(vm_bo, &bo->base) {
+ if (xe_vm_is_validating(gpuvm_to_vm(vm_bo->vm)))
+ return false;
+ }
+
+ return true;
+}
+
/**
* xe_bo_shrink() - Try to shrink an xe bo.
* @ctx: The struct ttm_operation_ctx used for shrinking.
(flags.purge && !xe_tt->purgeable))
return -EBUSY;
- if (!ttm_bo_eviction_valuable(bo, &place))
+ if (!xe_bo_eviction_valuable(bo, &place))
return -EBUSY;
if (!xe_bo_is_xe_bo(bo) || !xe_bo_get_unless_zero(xe_bo))
.io_mem_pfn = xe_ttm_io_mem_pfn,
.access_memory = xe_ttm_access_memory,
.release_notify = xe_ttm_bo_release_notify,
- .eviction_valuable = ttm_bo_eviction_valuable,
+ .eviction_valuable = xe_bo_eviction_valuable,
.delete_mem_notify = xe_ttm_bo_delete_mem_notify,
.swap_notify = xe_ttm_bo_swap_notify,
};
.no_wait_gpu = false,
.gfp_retry_mayfail = true,
};
+ struct pin_cookie cookie;
+ int ret;
if (vm) {
lockdep_assert_held(&vm->lock);
ctx.resv = xe_vm_resv(vm);
}
+ cookie = xe_vm_set_validating(vm, allow_res_evict);
trace_xe_bo_validate(bo);
- return ttm_bo_validate(&bo->ttm, &bo->placement, &ctx);
+ ret = ttm_bo_validate(&bo->ttm, &bo->placement, &ctx);
+ xe_vm_clear_validating(vm, allow_res_evict, cookie);
+
+ return ret;
}
bool xe_bo_is_xe_bo(struct ttm_buffer_object *bo)
void xe_vm_snapshot_print(struct xe_vm_snapshot *snap, struct drm_printer *p);
void xe_vm_snapshot_free(struct xe_vm_snapshot *snap);
+/**
+ * xe_vm_set_validating() - Register this task as currently making bos resident
+ * @allow_res_evict: Allow eviction of buffer objects bound to @vm when
+ * validating.
+ * @vm: Pointer to the vm or NULL.
+ *
+ * Register this task as currently making bos resident for the vm. Intended
+ * to avoid eviction by the same task of shared bos bound to the vm.
+ * Call with the vm's resv lock held.
+ *
+ * Return: A pin cookie that should be used for xe_vm_clear_validating().
+ */
+static inline struct pin_cookie xe_vm_set_validating(struct xe_vm *vm,
+ bool allow_res_evict)
+{
+ struct pin_cookie cookie = {};
+
+ if (vm && !allow_res_evict) {
+ xe_vm_assert_held(vm);
+ cookie = lockdep_pin_lock(&xe_vm_resv(vm)->lock.base);
+ /* Pairs with READ_ONCE in xe_vm_is_validating() */
+ WRITE_ONCE(vm->validating, current);
+ }
+
+ return cookie;
+}
+
+/**
+ * xe_vm_clear_validating() - Unregister this task as currently making bos resident
+ * @vm: Pointer to the vm or NULL
+ * @allow_res_evict: Eviction from @vm was allowed. Must be set to the same
+ * value as for xe_vm_set_validation().
+ * @cookie: Cookie obtained from xe_vm_set_validating().
+ *
+ * Register this task as currently making bos resident for the vm. Intended
+ * to avoid eviction by the same task of shared bos bound to the vm.
+ * Call with the vm's resv lock held.
+ */
+static inline void xe_vm_clear_validating(struct xe_vm *vm, bool allow_res_evict,
+ struct pin_cookie cookie)
+{
+ if (vm && !allow_res_evict) {
+ lockdep_unpin_lock(&xe_vm_resv(vm)->lock.base, cookie);
+ /* Pairs with READ_ONCE in xe_vm_is_validating() */
+ WRITE_ONCE(vm->validating, NULL);
+ }
+}
+
+/**
+ * xe_vm_is_validating() - Whether bos bound to the vm are currently being made resident
+ * by the current task.
+ * @vm: Pointer to the vm.
+ *
+ * If this function returns %true, we should be in a vm resv locked region, since
+ * the current process is the same task that called xe_vm_set_validating().
+ * The function asserts that that's indeed the case.
+ *
+ * Return: %true if the task is currently making bos resident, %false otherwise.
+ */
+static inline bool xe_vm_is_validating(struct xe_vm *vm)
+{
+ /* Pairs with WRITE_ONCE in xe_vm_is_validating() */
+ if (READ_ONCE(vm->validating) == current) {
+ xe_vm_assert_held(vm);
+ return true;
+ }
+ return false;
+}
+
#if IS_ENABLED(CONFIG_DRM_XE_USERPTR_INVAL_INJECT)
void xe_vma_userptr_force_invalidate(struct xe_userptr_vma *uvma);
#else
* protected by the vm resv.
*/
u64 tlb_flush_seqno;
+ /**
+ * @validating: The task that is currently making bos resident for this vm.
+ * Protected by the VM's resv for writing. Opportunistic reading can be done
+ * using READ_ONCE. Note: This is a workaround for the
+ * TTM eviction_valuable() callback not being passed a struct
+ * ttm_operation_context(). Future work might want to address this.
+ */
+ struct task_struct *validating;
/** @batch_invalidate_tlb: Always invalidate TLB before batch start */
bool batch_invalidate_tlb;
/** @xef: XE file handle for tracking this VM's drm client */
projects / linux-2.6-microblaze.git / commitdiff