Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull vhost updates from Michael Tsirkin:
"virtio, vhost: optimizations, fixes
Looks like a quiet cycle for vhost/virtio, just a couple of minor
tweaks. Most notable is automatic interrupt affinity for blk and scsi.
Hopefully other devices are not far behind"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio-console: avoid DMA from stack
vhost: introduce O(1) vq metadata cache
virtio_scsi: use virtio IRQ affinity
virtio_blk: use virtio IRQ affinity
blk-mq: provide a default queue mapping for virtio device
virtio: provide a method to get the IRQ affinity mask for a virtqueue
virtio: allow drivers to request IRQ affinity when creating VQs
virtio_pci: simplify MSI-X setup
virtio_pci: don't duplicate the msix_enable flag in struct pci_dev
virtio_pci: use shared interrupts for virtqueues
virtio_pci: remove struct virtio_pci_vq_info
vhost: try avoiding avail index access when getting descriptor
virtio_mmio: expose header to userspace
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 4269e62..9469364 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -282,6 +282,22 @@ void vhost_poll_queue(struct vhost_poll *poll)
}
EXPORT_SYMBOL_GPL(vhost_poll_queue);
+static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq)
+{
+ int j;
+
+ for (j = 0; j < VHOST_NUM_ADDRS; j++)
+ vq->meta_iotlb[j] = NULL;
+}
+
+static void vhost_vq_meta_reset(struct vhost_dev *d)
+{
+ int i;
+
+ for (i = 0; i < d->nvqs; ++i)
+ __vhost_vq_meta_reset(d->vqs[i]);
+}
+
static void vhost_vq_reset(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
{
@@ -312,6 +328,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->busyloop_timeout = 0;
vq->umem = NULL;
vq->iotlb = NULL;
+ __vhost_vq_meta_reset(vq);
}
static int vhost_worker(void *data)
@@ -691,6 +708,18 @@ static int vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem,
return 1;
}
+static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq,
+ u64 addr, unsigned int size,
+ int type)
+{
+ const struct vhost_umem_node *node = vq->meta_iotlb[type];
+
+ if (!node)
+ return NULL;
+
+ return (void *)(uintptr_t)(node->userspace_addr + addr - node->start);
+}
+
/* Can we switch to this memory table? */
/* Caller should have device mutex but not vq mutex */
static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem,
@@ -733,8 +762,14 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to,
* could be access through iotlb. So -EAGAIN should
* not happen in this case.
*/
- /* TODO: more fast path */
struct iov_iter t;
+ void __user *uaddr = vhost_vq_meta_fetch(vq,
+ (u64)(uintptr_t)to, size,
+ VHOST_ADDR_DESC);
+
+ if (uaddr)
+ return __copy_to_user(uaddr, from, size);
+
ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov,
ARRAY_SIZE(vq->iotlb_iov),
VHOST_ACCESS_WO);
@@ -762,8 +797,14 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
* could be access through iotlb. So -EAGAIN should
* not happen in this case.
*/
- /* TODO: more fast path */
+ void __user *uaddr = vhost_vq_meta_fetch(vq,
+ (u64)(uintptr_t)from, size,
+ VHOST_ADDR_DESC);
struct iov_iter f;
+
+ if (uaddr)
+ return __copy_from_user(to, uaddr, size);
+
ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov,
ARRAY_SIZE(vq->iotlb_iov),
VHOST_ACCESS_RO);
@@ -783,17 +824,12 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to,
return ret;
}
-static void __user *__vhost_get_user(struct vhost_virtqueue *vq,
- void __user *addr, unsigned size)
+static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq,
+ void __user *addr, unsigned int size,
+ int type)
{
int ret;
- /* This function should be called after iotlb
- * prefetch, which means we're sure that vq
- * could be access through iotlb. So -EAGAIN should
- * not happen in this case.
- */
- /* TODO: more fast path */
ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov,
ARRAY_SIZE(vq->iotlb_iov),
VHOST_ACCESS_RO);
@@ -814,14 +850,32 @@ static void __user *__vhost_get_user(struct vhost_virtqueue *vq,
return vq->iotlb_iov[0].iov_base;
}
-#define vhost_put_user(vq, x, ptr) \
+/* This function should be called after iotlb
+ * prefetch, which means we're sure that vq
+ * could be access through iotlb. So -EAGAIN should
+ * not happen in this case.
+ */
+static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq,
+ void *addr, unsigned int size,
+ int type)
+{
+ void __user *uaddr = vhost_vq_meta_fetch(vq,
+ (u64)(uintptr_t)addr, size, type);
+ if (uaddr)
+ return uaddr;
+
+ return __vhost_get_user_slow(vq, addr, size, type);
+}
+
+#define vhost_put_user(vq, x, ptr) \
({ \
int ret = -EFAULT; \
if (!vq->iotlb) { \
ret = __put_user(x, ptr); \
} else { \
__typeof__(ptr) to = \
- (__typeof__(ptr)) __vhost_get_user(vq, ptr, sizeof(*ptr)); \
+ (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
+ sizeof(*ptr), VHOST_ADDR_USED); \
if (to != NULL) \
ret = __put_user(x, to); \
else \
@@ -830,14 +884,16 @@ static void __user *__vhost_get_user(struct vhost_virtqueue *vq,
ret; \
})
-#define vhost_get_user(vq, x, ptr) \
+#define vhost_get_user(vq, x, ptr, type) \
({ \
int ret; \
if (!vq->iotlb) { \
ret = __get_user(x, ptr); \
} else { \
__typeof__(ptr) from = \
- (__typeof__(ptr)) __vhost_get_user(vq, ptr, sizeof(*ptr)); \
+ (__typeof__(ptr)) __vhost_get_user(vq, ptr, \
+ sizeof(*ptr), \
+ type); \
if (from != NULL) \
ret = __get_user(x, from); \
else \
@@ -846,6 +902,12 @@ static void __user *__vhost_get_user(struct vhost_virtqueue *vq,
ret; \
})
+#define vhost_get_avail(vq, x, ptr) \
+ vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL)
+
+#define vhost_get_used(vq, x, ptr) \
+ vhost_get_user(vq, x, ptr, VHOST_ADDR_USED)
+
static void vhost_dev_lock_vqs(struct vhost_dev *d)
{
int i = 0;
@@ -951,6 +1013,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
ret = -EFAULT;
break;
}
+ vhost_vq_meta_reset(dev);
if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size,
msg->iova + msg->size - 1,
msg->uaddr, msg->perm)) {
@@ -960,6 +1023,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
vhost_iotlb_notify_vq(dev, msg);
break;
case VHOST_IOTLB_INVALIDATE:
+ vhost_vq_meta_reset(dev);
vhost_del_umem_range(dev->iotlb, msg->iova,
msg->iova + msg->size - 1);
break;
@@ -1103,12 +1167,26 @@ static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
sizeof *used + num * sizeof *used->ring + s);
}
+static void vhost_vq_meta_update(struct vhost_virtqueue *vq,
+ const struct vhost_umem_node *node,
+ int type)
+{
+ int access = (type == VHOST_ADDR_USED) ?
+ VHOST_ACCESS_WO : VHOST_ACCESS_RO;
+
+ if (likely(node->perm & access))
+ vq->meta_iotlb[type] = node;
+}
+
static int iotlb_access_ok(struct vhost_virtqueue *vq,
- int access, u64 addr, u64 len)
+ int access, u64 addr, u64 len, int type)
{
const struct vhost_umem_node *node;
struct vhost_umem *umem = vq->iotlb;
- u64 s = 0, size;
+ u64 s = 0, size, orig_addr = addr;
+
+ if (vhost_vq_meta_fetch(vq, addr, len, type))
+ return true;
while (len > s) {
node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
@@ -1125,6 +1203,10 @@ static int iotlb_access_ok(struct vhost_virtqueue *vq,
}
size = node->size - addr + node->start;
+
+ if (orig_addr == addr && size >= len)
+ vhost_vq_meta_update(vq, node, type);
+
s += size;
addr += size;
}
@@ -1141,13 +1223,15 @@ int vq_iotlb_prefetch(struct vhost_virtqueue *vq)
return 1;
return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc,
- num * sizeof *vq->desc) &&
+ num * sizeof(*vq->desc), VHOST_ADDR_DESC) &&
iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail,
sizeof *vq->avail +
- num * sizeof *vq->avail->ring + s) &&
+ num * sizeof(*vq->avail->ring) + s,
+ VHOST_ADDR_AVAIL) &&
iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used,
sizeof *vq->used +
- num * sizeof *vq->used->ring + s);
+ num * sizeof(*vq->used->ring) + s,
+ VHOST_ADDR_USED);
}
EXPORT_SYMBOL_GPL(vq_iotlb_prefetch);
@@ -1728,7 +1812,7 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq)
r = -EFAULT;
goto err;
}
- r = vhost_get_user(vq, last_used_idx, &vq->used->idx);
+ r = vhost_get_used(vq, last_used_idx, &vq->used->idx);
if (r) {
vq_err(vq, "Can't access used idx at %p\n",
&vq->used->idx);
@@ -1930,29 +2014,36 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
/* Check it isn't doing very strange things with descriptor numbers. */
last_avail_idx = vq->last_avail_idx;
- if (unlikely(vhost_get_user(vq, avail_idx, &vq->avail->idx))) {
- vq_err(vq, "Failed to access avail idx at %p\n",
- &vq->avail->idx);
- return -EFAULT;
+
+ if (vq->avail_idx == vq->last_avail_idx) {
+ if (unlikely(vhost_get_avail(vq, avail_idx, &vq->avail->idx))) {
+ vq_err(vq, "Failed to access avail idx at %p\n",
+ &vq->avail->idx);
+ return -EFAULT;
+ }
+ vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
+
+ if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
+ vq_err(vq, "Guest moved used index from %u to %u",
+ last_avail_idx, vq->avail_idx);
+ return -EFAULT;
+ }
+
+ /* If there's nothing new since last we looked, return
+ * invalid.
+ */
+ if (vq->avail_idx == last_avail_idx)
+ return vq->num;
+
+ /* Only get avail ring entries after they have been
+ * exposed by guest.
+ */
+ smp_rmb();
}
- vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
-
- if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) {
- vq_err(vq, "Guest moved used index from %u to %u",
- last_avail_idx, vq->avail_idx);
- return -EFAULT;
- }
-
- /* If there's nothing new since last we looked, return invalid. */
- if (vq->avail_idx == last_avail_idx)
- return vq->num;
-
- /* Only get avail ring entries after they have been exposed by guest. */
- smp_rmb();
/* Grab the next descriptor number they're advertising, and increment
* the index we've seen. */
- if (unlikely(vhost_get_user(vq, ring_head,
+ if (unlikely(vhost_get_avail(vq, ring_head,
&vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {
vq_err(vq, "Failed to read head: idx %d address %p\n",
last_avail_idx,
@@ -2168,7 +2259,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
* with the barrier that the Guest executes when enabling
* interrupts. */
smp_mb();
- if (vhost_get_user(vq, flags, &vq->avail->flags)) {
+ if (vhost_get_avail(vq, flags, &vq->avail->flags)) {
vq_err(vq, "Failed to get flags");
return true;
}
@@ -2195,7 +2286,7 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
* interrupts. */
smp_mb();
- if (vhost_get_user(vq, event, vhost_used_event(vq))) {
+ if (vhost_get_avail(vq, event, vhost_used_event(vq))) {
vq_err(vq, "Failed to get used event idx");
return true;
}
@@ -2242,7 +2333,7 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
if (vq->avail_idx != vq->last_avail_idx)
return false;
- r = vhost_get_user(vq, avail_idx, &vq->avail->idx);
+ r = vhost_get_avail(vq, avail_idx, &vq->avail->idx);
if (unlikely(r))
return false;
vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
@@ -2278,7 +2369,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
/* They could have slipped one in as we were doing that: make
* sure it's written, then check again. */
smp_mb();
- r = vhost_get_user(vq, avail_idx, &vq->avail->idx);
+ r = vhost_get_avail(vq, avail_idx, &vq->avail->idx);
if (r) {
vq_err(vq, "Failed to check avail idx at %p: %d\n",
&vq->avail->idx, r);