We cannot let user fences exported as dma-fence run forever. Add a TDR
to protect against this. If the TDR fires the entire VM is killed as
dma-fences are not tied to an individual queue.
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_vm.c | 164 +++++++++++++++++++++++++++++--
drivers/gpu/drm/xe/xe_vm_types.h | 22 +++++
2 files changed, 179 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 5078aeea2bd8..8b475e76bfe0 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -30,6 +30,7 @@
#include "xe_exec_queue.h"
#include "xe_gt_pagefault.h"
#include "xe_gt_tlb_invalidation.h"
+#include "xe_hw_fence.h"
#include "xe_migrate.h"
#include "xe_pat.h"
#include "xe_pm.h"
@@ -336,11 +337,15 @@ void xe_vm_kill(struct xe_vm *vm, bool unlocked)
if (unlocked)
xe_vm_lock(vm, false);
- vm->flags |= XE_VM_FLAG_BANNED;
- trace_xe_vm_kill(vm);
+ if (!(vm->flags |= XE_VM_FLAG_BANNED)) {
+ vm->flags |= XE_VM_FLAG_BANNED;
+ trace_xe_vm_kill(vm);
- list_for_each_entry(q, &vm->preempt.exec_queues, lr.link)
- q->ops->kill(q);
+ list_for_each_entry(q, &vm->preempt.exec_queues, lr.link)
+ q->ops->kill(q);
+
+ /* TODO: Unmap usermap doorbells */
+ }
if (unlocked)
xe_vm_unlock(vm);
@@ -1393,6 +1398,9 @@ static void xe_vm_free_scratch(struct xe_vm *vm)
}
}
+static void userfence_tdr(struct work_struct *w);
+static void userfence_kill(struct work_struct *w);
+
struct xe_vm *xe_vm_create(struct xe_device *xe, u32 flags)
{
struct drm_gem_object *vm_resv_obj;
@@ -1517,6 +1525,12 @@ struct xe_vm *xe_vm_create(struct xe_device *xe, u32 flags)
}
}
+ spin_lock_init(&vm->userfence.lock);
+ INIT_LIST_HEAD(&vm->userfence.pending_list);
+ vm->userfence.timeout = HZ * 5;
+ INIT_DELAYED_WORK(&vm->userfence.tdr, userfence_tdr);
+ INIT_WORK(&vm->userfence.kill_work, userfence_kill);
+
if (number_tiles > 1)
vm->composite_fence_ctx = dma_fence_context_alloc(1);
@@ -1562,6 +1576,9 @@ void xe_vm_close_and_put(struct xe_vm *vm)
xe_vm_close(vm);
flush_work(&vm->preempt.rebind_work);
+ flush_delayed_work(&vm->userfence.tdr);
+ flush_work(&vm->userfence.kill_work);
+
down_write(&vm->lock);
for_each_tile(tile, xe, id) {
if (vm->q[id])
@@ -3449,6 +3466,114 @@ static int check_semaphores(struct xe_vm *vm, struct xe_sync_entry *syncs,
return 0;
}
+struct tdr_item {
+ struct dma_fence *fence;
+ struct xe_vm *vm;
+ struct list_head link;
+ struct dma_fence_cb cb;
+ u64 deadline;
+};
+
+static void userfence_kill(struct work_struct *w)
+{
+ struct xe_vm *vm =
+ container_of(w, struct xe_vm, userfence.kill_work);
+
+ down_write(&vm->lock);
+ xe_vm_kill(vm, true);
+ up_write(&vm->lock);
+}
+
+static void userfence_tdr(struct work_struct *w)
+{
+ struct xe_vm *vm =
+ container_of(w, struct xe_vm, userfence.tdr.work);
+ struct tdr_item *tdr_item;
+ bool timeout = false, cookie = dma_fence_begin_signalling();
+
+ xe_hw_fence_irq_stop(&vm->xe->user_fence_irq);
+
+ spin_lock_irq(&vm->userfence.lock);
+ list_for_each_entry(tdr_item, &vm->userfence.pending_list, link) {
+ if (!dma_fence_is_signaled(tdr_item->fence)) {
+ drm_notice(&vm->xe->drm,
+ "Timedout usermap fence: seqno=%llu, deadline=%llu, jiffies=%llu",
+ tdr_item->fence->seqno, tdr_item->deadline,
+ get_jiffies_64());
+ dma_fence_set_error(tdr_item->fence, -ETIME);
+ timeout = true;
+ vm->userfence.timeout = 0;
+ }
+ }
+ spin_unlock_irq(&vm->userfence.lock);
+
+ xe_hw_fence_irq_start(&vm->xe->user_fence_irq);
+
+ /*
+ * This is dma-fence signaling path so we cannot take the locks requires
+ * to kill a VM. Defer killing to a worker.
+ */
+ if (timeout)
+ schedule_work(&vm->userfence.kill_work);
+
+ dma_fence_end_signalling(cookie);
+}
+
+static void userfence_fence_cb(struct dma_fence *fence,
+ struct dma_fence_cb *cb)
+{
+ struct tdr_item *next, *tdr_item = container_of(cb, struct tdr_item, cb);
+ struct xe_vm *vm = tdr_item->vm;
+ struct xe_gt *gt = xe_device_get_gt(vm->xe, 0);
+
+ if (fence)
+ spin_lock(&vm->userfence.lock);
+ else
+ spin_lock_irq(&vm->userfence.lock);
+
+ list_del(&tdr_item->link);
+ next = list_first_entry_or_null(&vm->userfence.pending_list,
+ typeof(*next), link);
+ if (next)
+ mod_delayed_work(gt->ordered_wq, &vm->userfence.tdr,
+ next->deadline - get_jiffies_64());
+ else
+ cancel_delayed_work(&vm->userfence.tdr);
+
+ if (fence)
+ spin_unlock(&vm->userfence.lock);
+ else
+ spin_unlock_irq(&vm->userfence.lock);
+
+ dma_fence_put(tdr_item->fence);
+ xe_vm_put(tdr_item->vm);
+ kfree(tdr_item);
+}
+
+static void userfence_tdr_add(struct xe_vm *vm, struct tdr_item *tdr_item,
+ struct dma_fence *fence)
+{
+ struct xe_gt *gt = xe_device_get_gt(vm->xe, 0);
+ int ret;
+
+ tdr_item->fence = dma_fence_get(fence);
+ tdr_item->vm = xe_vm_get(vm);
+ INIT_LIST_HEAD(&tdr_item->link);
+ tdr_item->deadline = vm->userfence.timeout + get_jiffies_64();
+
+ spin_lock_irq(&vm->userfence.lock);
+ list_add_tail(&tdr_item->link, &vm->userfence.pending_list);
+ if (list_is_singular(&vm->userfence.pending_list))
+ mod_delayed_work(gt->ordered_wq,
+ &vm->userfence.tdr,
+ vm->userfence.timeout);
+ spin_unlock_irq(&vm->userfence.lock);
+
+ ret = dma_fence_add_callback(fence, &tdr_item->cb, userfence_fence_cb);
+ if (ret == -ENOENT)
+ userfence_fence_cb(NULL, &tdr_item->cb);
+}
+
int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
@@ -3459,6 +3584,7 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
struct drm_xe_semaphore __user *semaphores_user;
struct xe_sync_entry *syncs = NULL;
struct xe_vm *vm;
+ struct tdr_item **tdr_items = NULL;
int err = 0, i, num_syncs = 0;
bool done = false;
struct drm_exec exec;
@@ -3493,6 +3619,12 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
goto release_vm_lock;
}
+ tdr_items = kcalloc(args->num_syncs, sizeof(*tdr_items), GFP_KERNEL);
+ if (!tdr_items) {
+ err = -ENOMEM;
+ goto release_vm_lock;
+ }
+
syncs_user = u64_to_user_ptr(args->syncs);
semaphores_user = u64_to_user_ptr(args->semaphores);
for (i = 0; i < args->num_syncs; i++, num_syncs++) {
@@ -3505,6 +3637,15 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
if (err)
goto release_syncs;
+ if (sync->flags & DRM_XE_SYNC_FLAG_SIGNAL) {
+ tdr_items[i] = kmalloc(sizeof(struct tdr_item),
+ GFP_KERNEL);
+ if (!tdr_items[i]) {
+ xe_sync_entry_cleanup(&syncs[i]);
+ goto release_syncs;
+ }
+ }
+
err = xe_sync_semaphore_parse(xe, xef, semaphore_sync,
&semaphores_user[i],
sync->flags);
@@ -3591,6 +3732,10 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
&semaphore_sync->chain_fence->base;
semaphore_sync->chain_fence = NULL;
+ userfence_tdr_add(vm, tdr_items[i],
+ semaphore_sync->fence);
+ tdr_items[i] = 0;
+
semaphore_sync->fence = NULL; /* Ref owned by chain */
} else {
xe_sync_entry_signal(semaphore_sync, sync->fence);
@@ -3617,9 +3762,13 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
out_unlock:
drm_exec_fini(&exec);
release_syncs:
- while (err != -EAGAIN && num_syncs--) {
- xe_sync_entry_cleanup(&syncs[num_syncs]);
- xe_sync_entry_cleanup(&syncs[args->num_syncs + num_syncs]);
+ if (err != -EAGAIN) {
+ for (i = 0; i < num_syncs; ++i)
+ kfree(tdr_items[i]);
+ while (num_syncs--) {
+ xe_sync_entry_cleanup(&syncs[num_syncs]);
+ xe_sync_entry_cleanup(&syncs[args->num_syncs + num_syncs]);
+ }
}
release_vm_lock:
if (err == -EAGAIN)
@@ -3629,6 +3778,7 @@ int xe_vm_convert_fence_ioctl(struct drm_device *dev, void *data,
xe_vm_put(vm);
free_preempt_fences(&preempt_fences);
kfree(syncs);
+ kfree(tdr_items);
return err;
}
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index c5cb83722706..49cac5716f72 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -260,6 +260,28 @@ struct xe_vm {
struct dma_fence *exported_fence;
} preempt;
+ /** @userfence: User fence state */
+ struct {
+ /**
+ * @userfence.lock: fence lock
+ */
+ spinlock_t lock;
+ /**
+ * @userfence.pending_list: pending fence list, protected by
+ * userfence.lock
+ */
+ struct list_head pending_list;
+ /** @userfence.tdr: fence TDR */
+ struct delayed_work tdr;
+ /** @userfence.kill_work */
+ struct work_struct kill_work;
+ /**
+ * @userfence.timeout: Fence timeout period, protected by
+ * userfence.lock
+ */
+ u32 timeout;
+ } userfence;
+
/** @um: unified memory state */
struct {
/** @asid: address space ID, unique to each VM */
--
2.34.1
