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Diffstat (limited to 'drivers/virtio/virtio_ring.c')
-rw-r--r--drivers/virtio/virtio_ring.c89
1 files changed, 60 insertions, 29 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 13a7348cedff..643ca779fcc6 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -111,7 +111,12 @@ struct vring_virtqueue {
/* Number we've added since last sync. */
unsigned int num_added;
- /* Last used index we've seen. */
+ /* Last used index we've seen.
+ * for split ring, it just contains last used index
+ * for packed ring:
+ * bits up to VRING_PACKED_EVENT_F_WRAP_CTR include the last used index.
+ * bits from VRING_PACKED_EVENT_F_WRAP_CTR include the used wrap counter.
+ */
u16 last_used_idx;
/* Hint for event idx: already triggered no need to disable. */
@@ -154,9 +159,6 @@ struct vring_virtqueue {
/* Driver ring wrap counter. */
bool avail_wrap_counter;
- /* Device ring wrap counter. */
- bool used_wrap_counter;
-
/* Avail used flags. */
u16 avail_used_flags;
@@ -933,7 +935,7 @@ static struct virtqueue *vring_create_virtqueue_split(
for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
&dma_addr,
- GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
+ GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
if (queue)
break;
if (!may_reduce_num)
@@ -973,6 +975,15 @@ static struct virtqueue *vring_create_virtqueue_split(
/*
* Packed ring specific functions - *_packed().
*/
+static inline bool packed_used_wrap_counter(u16 last_used_idx)
+{
+ return !!(last_used_idx & (1 << VRING_PACKED_EVENT_F_WRAP_CTR));
+}
+
+static inline u16 packed_last_used(u16 last_used_idx)
+{
+ return last_used_idx & ~(-(1 << VRING_PACKED_EVENT_F_WRAP_CTR));
+}
static void vring_unmap_extra_packed(const struct vring_virtqueue *vq,
struct vring_desc_extra *extra)
@@ -1406,8 +1417,14 @@ static inline bool is_used_desc_packed(const struct vring_virtqueue *vq,
static inline bool more_used_packed(const struct vring_virtqueue *vq)
{
- return is_used_desc_packed(vq, vq->last_used_idx,
- vq->packed.used_wrap_counter);
+ u16 last_used;
+ u16 last_used_idx;
+ bool used_wrap_counter;
+
+ last_used_idx = READ_ONCE(vq->last_used_idx);
+ last_used = packed_last_used(last_used_idx);
+ used_wrap_counter = packed_used_wrap_counter(last_used_idx);
+ return is_used_desc_packed(vq, last_used, used_wrap_counter);
}
static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
@@ -1415,7 +1432,8 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
void **ctx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
- u16 last_used, id;
+ u16 last_used, id, last_used_idx;
+ bool used_wrap_counter;
void *ret;
START_USE(vq);
@@ -1434,7 +1452,9 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
/* Only get used elements after they have been exposed by host. */
virtio_rmb(vq->weak_barriers);
- last_used = vq->last_used_idx;
+ last_used_idx = READ_ONCE(vq->last_used_idx);
+ used_wrap_counter = packed_used_wrap_counter(last_used_idx);
+ last_used = packed_last_used(last_used_idx);
id = le16_to_cpu(vq->packed.vring.desc[last_used].id);
*len = le32_to_cpu(vq->packed.vring.desc[last_used].len);
@@ -1451,12 +1471,15 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
ret = vq->packed.desc_state[id].data;
detach_buf_packed(vq, id, ctx);
- vq->last_used_idx += vq->packed.desc_state[id].num;
- if (unlikely(vq->last_used_idx >= vq->packed.vring.num)) {
- vq->last_used_idx -= vq->packed.vring.num;
- vq->packed.used_wrap_counter ^= 1;
+ last_used += vq->packed.desc_state[id].num;
+ if (unlikely(last_used >= vq->packed.vring.num)) {
+ last_used -= vq->packed.vring.num;
+ used_wrap_counter ^= 1;
}
+ last_used = (last_used | (used_wrap_counter << VRING_PACKED_EVENT_F_WRAP_CTR));
+ WRITE_ONCE(vq->last_used_idx, last_used);
+
/*
* If we expect an interrupt for the next entry, tell host
* by writing event index and flush out the write before
@@ -1465,9 +1488,7 @@ static void *virtqueue_get_buf_ctx_packed(struct virtqueue *_vq,
if (vq->packed.event_flags_shadow == VRING_PACKED_EVENT_FLAG_DESC)
virtio_store_mb(vq->weak_barriers,
&vq->packed.vring.driver->off_wrap,
- cpu_to_le16(vq->last_used_idx |
- (vq->packed.used_wrap_counter <<
- VRING_PACKED_EVENT_F_WRAP_CTR)));
+ cpu_to_le16(vq->last_used_idx));
LAST_ADD_TIME_INVALID(vq);
@@ -1499,9 +1520,7 @@ static unsigned int virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq)
if (vq->event) {
vq->packed.vring.driver->off_wrap =
- cpu_to_le16(vq->last_used_idx |
- (vq->packed.used_wrap_counter <<
- VRING_PACKED_EVENT_F_WRAP_CTR));
+ cpu_to_le16(vq->last_used_idx);
/*
* We need to update event offset and event wrap
* counter first before updating event flags.
@@ -1518,8 +1537,7 @@ static unsigned int virtqueue_enable_cb_prepare_packed(struct virtqueue *_vq)
}
END_USE(vq);
- return vq->last_used_idx | ((u16)vq->packed.used_wrap_counter <<
- VRING_PACKED_EVENT_F_WRAP_CTR);
+ return vq->last_used_idx;
}
static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap)
@@ -1537,7 +1555,7 @@ static bool virtqueue_poll_packed(struct virtqueue *_vq, u16 off_wrap)
static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
- u16 used_idx, wrap_counter;
+ u16 used_idx, wrap_counter, last_used_idx;
u16 bufs;
START_USE(vq);
@@ -1550,9 +1568,10 @@ static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq)
if (vq->event) {
/* TODO: tune this threshold */
bufs = (vq->packed.vring.num - vq->vq.num_free) * 3 / 4;
- wrap_counter = vq->packed.used_wrap_counter;
+ last_used_idx = READ_ONCE(vq->last_used_idx);
+ wrap_counter = packed_used_wrap_counter(last_used_idx);
- used_idx = vq->last_used_idx + bufs;
+ used_idx = packed_last_used(last_used_idx) + bufs;
if (used_idx >= vq->packed.vring.num) {
used_idx -= vq->packed.vring.num;
wrap_counter ^= 1;
@@ -1582,9 +1601,10 @@ static bool virtqueue_enable_cb_delayed_packed(struct virtqueue *_vq)
*/
virtio_mb(vq->weak_barriers);
- if (is_used_desc_packed(vq,
- vq->last_used_idx,
- vq->packed.used_wrap_counter)) {
+ last_used_idx = READ_ONCE(vq->last_used_idx);
+ wrap_counter = packed_used_wrap_counter(last_used_idx);
+ used_idx = packed_last_used(last_used_idx);
+ if (is_used_desc_packed(vq, used_idx, wrap_counter)) {
END_USE(vq);
return false;
}
@@ -1688,8 +1708,12 @@ static struct virtqueue *vring_create_virtqueue_packed(
vq->we_own_ring = true;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
+#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
vq->broken = true;
- vq->last_used_idx = 0;
+#else
+ vq->broken = false;
+#endif
+ vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR);
vq->event_triggered = false;
vq->num_added = 0;
vq->packed_ring = true;
@@ -1720,7 +1744,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
vq->packed.next_avail_idx = 0;
vq->packed.avail_wrap_counter = 1;
- vq->packed.used_wrap_counter = 1;
vq->packed.event_flags_shadow = 0;
vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;
@@ -2135,9 +2158,13 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
}
if (unlikely(vq->broken)) {
+#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
dev_warn_once(&vq->vq.vdev->dev,
"virtio vring IRQ raised before DRIVER_OK");
return IRQ_NONE;
+#else
+ return IRQ_HANDLED;
+#endif
}
/* Just a hint for performance: so it's ok that this can be racy! */
@@ -2180,7 +2207,11 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->we_own_ring = false;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
+#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
vq->broken = true;
+#else
+ vq->broken = false;
+#endif
vq->last_used_idx = 0;
vq->event_triggered = false;
vq->num_added = 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-18 07:08:52 +0000