* [PATCH v3 1/8] vhost: Create accessors for virtqueues private_data
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
@ 2020-03-31 19:27 ` Eugenio Pérez
2020-03-31 19:27 ` [PATCH v3 2/8] vhost: option to fetch descriptors through an independent struct Eugenio Pérez
` (8 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:27 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/net.c | 28 +++++++++++++++-------------
drivers/vhost/scsi.c | 14 +++++++-------
drivers/vhost/test.c | 10 +++++-----
drivers/vhost/vhost.h | 27 +++++++++++++++++++++++++++
drivers/vhost/vsock.c | 14 +++++++-------
5 files changed, 61 insertions(+), 32 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e158159671fa..6ad1612f496e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -424,7 +424,7 @@ static void vhost_net_disable_vq(struct vhost_net *n,
struct vhost_net_virtqueue *nvq =
container_of(vq, struct vhost_net_virtqueue, vq);
struct vhost_poll *poll = n->poll + (nvq - n->vqs);
- if (!vq->private_data)
+ if (!vhost_vq_get_backend(vq))
return;
vhost_poll_stop(poll);
}
@@ -437,7 +437,7 @@ static int vhost_net_enable_vq(struct vhost_net *n,
struct vhost_poll *poll = n->poll + (nvq - n->vqs);
struct socket *sock;
- sock = vq->private_data;
+ sock = vhost_vq_get_backend(vq);
if (!sock)
return 0;
@@ -524,7 +524,7 @@ static void vhost_net_busy_poll(struct vhost_net *net,
return;
vhost_disable_notify(&net->dev, vq);
- sock = rvq->private_data;
+ sock = vhost_vq_get_backend(rvq);
busyloop_timeout = poll_rx ? rvq->busyloop_timeout:
tvq->busyloop_timeout;
@@ -570,8 +570,10 @@ static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
if (r == tvq->num && tvq->busyloop_timeout) {
/* Flush batched packets first */
- if (!vhost_sock_zcopy(tvq->private_data))
- vhost_tx_batch(net, tnvq, tvq->private_data, msghdr);
+ if (!vhost_sock_zcopy(vhost_vq_get_backend(tvq)))
+ vhost_tx_batch(net, tnvq,
+ vhost_vq_get_backend(tvq),
+ msghdr);
vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false);
@@ -685,7 +687,7 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
struct vhost_virtqueue *vq = &nvq->vq;
struct vhost_net *net = container_of(vq->dev, struct vhost_net,
dev);
- struct socket *sock = vq->private_data;
+ struct socket *sock = vhost_vq_get_backend(vq);
struct page_frag *alloc_frag = &net->page_frag;
struct virtio_net_hdr *gso;
struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
@@ -952,7 +954,7 @@ static void handle_tx(struct vhost_net *net)
struct socket *sock;
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX);
- sock = vq->private_data;
+ sock = vhost_vq_get_backend(vq);
if (!sock)
goto out;
@@ -1121,7 +1123,7 @@ static void handle_rx(struct vhost_net *net)
int recv_pkts = 0;
mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
- sock = vq->private_data;
+ sock = vhost_vq_get_backend(vq);
if (!sock)
goto out;
@@ -1344,9 +1346,9 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
container_of(vq, struct vhost_net_virtqueue, vq);
mutex_lock(&vq->mutex);
- sock = vq->private_data;
+ sock = vhost_vq_get_backend(vq);
vhost_net_disable_vq(n, vq);
- vq->private_data = NULL;
+ vhost_vq_set_backend(vq, NULL);
vhost_net_buf_unproduce(nvq);
nvq->rx_ring = NULL;
mutex_unlock(&vq->mutex);
@@ -1528,7 +1530,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
}
/* start polling new socket */
- oldsock = vq->private_data;
+ oldsock = vhost_vq_get_backend(vq);
if (sock != oldsock) {
ubufs = vhost_net_ubuf_alloc(vq,
sock && vhost_sock_zcopy(sock));
@@ -1538,7 +1540,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
}
vhost_net_disable_vq(n, vq);
- vq->private_data = sock;
+ vhost_vq_set_backend(vq, sock);
vhost_net_buf_unproduce(nvq);
r = vhost_vq_init_access(vq);
if (r)
@@ -1575,7 +1577,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
return 0;
err_used:
- vq->private_data = oldsock;
+ vhost_vq_set_backend(vq, oldsock);
vhost_net_enable_vq(n, vq);
if (ubufs)
vhost_net_ubuf_put_wait_and_free(ubufs);
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 0b949a14bce3..4b5deeeabc3d 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -452,7 +452,7 @@ vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
unsigned out, in;
int head, ret;
- if (!vq->private_data) {
+ if (!vhost_vq_get_backend(vq)) {
vs->vs_events_missed = true;
return;
}
@@ -892,7 +892,7 @@ vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
} else {
struct vhost_scsi_tpg **vs_tpg, *tpg;
- vs_tpg = vq->private_data; /* validated at handler entry */
+ vs_tpg = vhost_vq_get_backend(vq); /* validated at handler entry */
tpg = READ_ONCE(vs_tpg[*vc->target]);
if (unlikely(!tpg)) {
@@ -929,7 +929,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
* We can handle the vq only after the endpoint is setup by calling the
* VHOST_SCSI_SET_ENDPOINT ioctl.
*/
- vs_tpg = vq->private_data;
+ vs_tpg = vhost_vq_get_backend(vq);
if (!vs_tpg)
goto out;
@@ -1184,7 +1184,7 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
* We can handle the vq only after the endpoint is setup by calling the
* VHOST_SCSI_SET_ENDPOINT ioctl.
*/
- if (!vq->private_data)
+ if (!vhost_vq_get_backend(vq))
goto out;
memset(&vc, 0, sizeof(vc));
@@ -1322,7 +1322,7 @@ static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
mutex_lock(&vq->mutex);
- if (!vq->private_data)
+ if (!vhost_vq_get_backend(vq))
goto out;
if (vs->vs_events_missed)
@@ -1460,7 +1460,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs,
for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
vq = &vs->vqs[i].vq;
mutex_lock(&vq->mutex);
- vq->private_data = vs_tpg;
+ vhost_vq_set_backend(vq, vs_tpg);
vhost_vq_init_access(vq);
mutex_unlock(&vq->mutex);
}
@@ -1547,7 +1547,7 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
vq = &vs->vqs[i].vq;
mutex_lock(&vq->mutex);
- vq->private_data = NULL;
+ vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
}
}
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index e37c92d4d7ad..394e2e5c772d 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -49,7 +49,7 @@ static void handle_vq(struct vhost_test *n)
void *private;
mutex_lock(&vq->mutex);
- private = vq->private_data;
+ private = vhost_vq_get_backend(vq);
if (!private) {
mutex_unlock(&vq->mutex);
return;
@@ -133,8 +133,8 @@ static void *vhost_test_stop_vq(struct vhost_test *n,
void *private;
mutex_lock(&vq->mutex);
- private = vq->private_data;
- vq->private_data = NULL;
+ private = vhost_vq_get_backend(vq);
+ vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
return private;
}
@@ -198,8 +198,8 @@ static long vhost_test_run(struct vhost_test *n, int test)
priv = test ? n : NULL;
/* start polling new socket */
- oldpriv = vq->private_data;
- vq->private_data = priv;
+ oldpriv = vhost_vq_get_backend(vq);
+ vhost_vq_set_backend(vq, priv);
r = vhost_vq_init_access(&n->vqs[index]);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a123fd70847e..b77203e0cae2 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -244,6 +244,33 @@ enum {
(1ULL << VIRTIO_F_VERSION_1)
};
+/**
+ * vhost_vq_set_backend - Set backend.
+ *
+ * @vq Virtqueue.
+ * @private_data The private data.
+ *
+ * Context: Need to call with vq->mutex acquired.
+ */
+static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
+ void *private_data)
+{
+ vq->private_data = private_data;
+}
+
+/**
+ * vhost_vq_get_backend - Get backend.
+ *
+ * @vq Virtqueue.
+ *
+ * Context: Need to call with vq->mutex acquired.
+ * Return: Private data previously set with vhost_vq_set_backend.
+ */
+static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
+{
+ return vq->private_data;
+}
+
static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
{
return vq->acked_features & (1ULL << bit);
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index c2d7d57e98cf..6c1fbfd621a2 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -91,7 +91,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
mutex_lock(&vq->mutex);
- if (!vq->private_data)
+ if (!vhost_vq_get_backend(vq))
goto out;
/* Avoid further vmexits, we're already processing the virtqueue */
@@ -440,7 +440,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
mutex_lock(&vq->mutex);
- if (!vq->private_data)
+ if (!vhost_vq_get_backend(vq))
goto out;
vhost_disable_notify(&vsock->dev, vq);
@@ -533,8 +533,8 @@ static int vhost_vsock_start(struct vhost_vsock *vsock)
goto err_vq;
}
- if (!vq->private_data) {
- vq->private_data = vsock;
+ if (!vhost_vq_get_backend(vq)) {
+ vhost_vq_set_backend(vq, vsock);
ret = vhost_vq_init_access(vq);
if (ret)
goto err_vq;
@@ -547,14 +547,14 @@ static int vhost_vsock_start(struct vhost_vsock *vsock)
return 0;
err_vq:
- vq->private_data = NULL;
+ vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
- vq->private_data = NULL;
+ vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
}
err:
@@ -577,7 +577,7 @@ static int vhost_vsock_stop(struct vhost_vsock *vsock)
struct vhost_virtqueue *vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
- vq->private_data = NULL;
+ vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
}
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 2/8] vhost: option to fetch descriptors through an independent struct
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
2020-03-31 19:27 ` [PATCH v3 1/8] vhost: Create accessors for virtqueues private_data Eugenio Pérez
@ 2020-03-31 19:27 ` Eugenio Pérez
2020-03-31 19:27 ` [PATCH v3 3/8] vhost: use batched version by default Eugenio Pérez
` (7 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:27 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
From: "Michael S. Tsirkin" <mst@redhat.com>
The idea is to support multiple ring formats by converting
to a format-independent array of descriptors.
This costs extra cycles, but we gain in ability
to fetch a batch of descriptors in one go, which
is good for code cache locality.
When used, this causes a minor performance degradation,
it's been kept as simple as possible for ease of review.
A follow-up patch gets us back the performance by adding batching.
To simplify benchmarking, I kept the old code around so one can switch
back and forth between old and new code. This will go away in the final
submission.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/vhost.c | 297 +++++++++++++++++++++++++++++++++++++++++-
drivers/vhost/vhost.h | 16 +++
2 files changed, 312 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index f44340b41494..38e65a36465b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -302,6 +302,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
{
vq->num = 1;
+ vq->ndescs = 0;
vq->desc = NULL;
vq->avail = NULL;
vq->used = NULL;
@@ -372,6 +373,9 @@ static int vhost_worker(void *data)
static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
{
+ kfree(vq->descs);
+ vq->descs = NULL;
+ vq->max_descs = 0;
kfree(vq->indirect);
vq->indirect = NULL;
kfree(vq->log);
@@ -388,6 +392,10 @@ static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
for (i = 0; i < dev->nvqs; ++i) {
vq = dev->vqs[i];
+ vq->max_descs = dev->iov_limit;
+ vq->descs = kmalloc_array(vq->max_descs,
+ sizeof(*vq->descs),
+ GFP_KERNEL);
vq->indirect = kmalloc_array(UIO_MAXIOV,
sizeof(*vq->indirect),
GFP_KERNEL);
@@ -395,7 +403,7 @@ static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
GFP_KERNEL);
vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads),
GFP_KERNEL);
- if (!vq->indirect || !vq->log || !vq->heads)
+ if (!vq->indirect || !vq->log || !vq->heads || !vq->descs)
goto err_nomem;
}
return 0;
@@ -2352,6 +2360,293 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
}
EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
+static struct vhost_desc *peek_split_desc(struct vhost_virtqueue *vq)
+{
+ BUG_ON(!vq->ndescs);
+ return &vq->descs[vq->ndescs - 1];
+}
+
+static void pop_split_desc(struct vhost_virtqueue *vq)
+{
+ BUG_ON(!vq->ndescs);
+ --vq->ndescs;
+}
+
+#define VHOST_DESC_FLAGS (VRING_DESC_F_INDIRECT | VRING_DESC_F_WRITE | \
+ VRING_DESC_F_NEXT)
+static int push_split_desc(struct vhost_virtqueue *vq, struct vring_desc *desc, u16 id)
+{
+ struct vhost_desc *h;
+
+ if (unlikely(vq->ndescs >= vq->max_descs))
+ return -EINVAL;
+ h = &vq->descs[vq->ndescs++];
+ h->addr = vhost64_to_cpu(vq, desc->addr);
+ h->len = vhost32_to_cpu(vq, desc->len);
+ h->flags = vhost16_to_cpu(vq, desc->flags) & VHOST_DESC_FLAGS;
+ h->id = id;
+
+ return 0;
+}
+
+static int fetch_indirect_descs(struct vhost_virtqueue *vq,
+ struct vhost_desc *indirect,
+ u16 head)
+{
+ struct vring_desc desc;
+ unsigned int i = 0, count, found = 0;
+ u32 len = indirect->len;
+ struct iov_iter from;
+ int ret;
+
+ /* Sanity check */
+ if (unlikely(len % sizeof desc)) {
+ vq_err(vq, "Invalid length in indirect descriptor: "
+ "len 0x%llx not multiple of 0x%zx\n",
+ (unsigned long long)len,
+ sizeof desc);
+ return -EINVAL;
+ }
+
+ ret = translate_desc(vq, indirect->addr, len, vq->indirect,
+ UIO_MAXIOV, VHOST_ACCESS_RO);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Translation failure %d in indirect.\n", ret);
+ return ret;
+ }
+ iov_iter_init(&from, READ, vq->indirect, ret, len);
+
+ /* We will use the result as an address to read from, so most
+ * architectures only need a compiler barrier here. */
+ read_barrier_depends();
+
+ count = len / sizeof desc;
+ /* Buffers are chained via a 16 bit next field, so
+ * we can have at most 2^16 of these. */
+ if (unlikely(count > USHRT_MAX + 1)) {
+ vq_err(vq, "Indirect buffer length too big: %d\n",
+ indirect->len);
+ return -E2BIG;
+ }
+ if (unlikely(vq->ndescs + count > vq->max_descs)) {
+ vq_err(vq, "Too many indirect + direct descs: %d + %d\n",
+ vq->ndescs, indirect->len);
+ return -E2BIG;
+ }
+
+ do {
+ if (unlikely(++found > count)) {
+ vq_err(vq, "Loop detected: last one at %u "
+ "indirect size %u\n",
+ i, count);
+ return -EINVAL;
+ }
+ if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) {
+ vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
+ i, (size_t)indirect->addr + i * sizeof desc);
+ return -EINVAL;
+ }
+ if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {
+ vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
+ i, (size_t)indirect->addr + i * sizeof desc);
+ return -EINVAL;
+ }
+
+ push_split_desc(vq, &desc, head);
+ } while ((i = next_desc(vq, &desc)) != -1);
+ return 0;
+}
+
+static int fetch_descs(struct vhost_virtqueue *vq)
+{
+ unsigned int i, head, found = 0;
+ struct vhost_desc *last;
+ struct vring_desc desc;
+ __virtio16 avail_idx;
+ __virtio16 ring_head;
+ u16 last_avail_idx;
+ int ret;
+
+ /* Check it isn't doing very strange things with descriptor numbers. */
+ last_avail_idx = vq->last_avail_idx;
+
+ if (vq->avail_idx == vq->last_avail_idx) {
+ if (unlikely(vhost_get_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();
+ }
+
+ /* Grab the next descriptor number they're advertising */
+ if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) {
+ vq_err(vq, "Failed to read head: idx %d address %p\n",
+ last_avail_idx,
+ &vq->avail->ring[last_avail_idx % vq->num]);
+ return -EFAULT;
+ }
+
+ head = vhost16_to_cpu(vq, ring_head);
+
+ /* If their number is silly, that's an error. */
+ if (unlikely(head >= vq->num)) {
+ vq_err(vq, "Guest says index %u > %u is available",
+ head, vq->num);
+ return -EINVAL;
+ }
+
+ i = head;
+ do {
+ if (unlikely(i >= vq->num)) {
+ vq_err(vq, "Desc index is %u > %u, head = %u",
+ i, vq->num, head);
+ return -EINVAL;
+ }
+ if (unlikely(++found > vq->num)) {
+ vq_err(vq, "Loop detected: last one at %u "
+ "vq size %u head %u\n",
+ i, vq->num, head);
+ return -EINVAL;
+ }
+ ret = vhost_get_desc(vq, &desc, i);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
+ i, vq->desc + i);
+ return -EFAULT;
+ }
+ ret = push_split_desc(vq, &desc, head);
+ if (unlikely(ret)) {
+ vq_err(vq, "Failed to save descriptor: idx %d\n", i);
+ return -EINVAL;
+ }
+ } while ((i = next_desc(vq, &desc)) != -1);
+
+ last = peek_split_desc(vq);
+ if (unlikely(last->flags & VRING_DESC_F_INDIRECT)) {
+ pop_split_desc(vq);
+ ret = fetch_indirect_descs(vq, last, head);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Failure detected "
+ "in indirect descriptor at idx %d\n", head);
+ return ret;
+ }
+ }
+
+ /* Assume notifications from guest are disabled at this point,
+ * if they aren't we would need to update avail_event index. */
+ BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
+
+ /* On success, increment avail index. */
+ vq->last_avail_idx++;
+
+ return 0;
+}
+
+/* This looks in the virtqueue and for the first available buffer, and converts
+ * it to an iovec for convenient access. Since descriptors consist of some
+ * number of output then some number of input descriptors, it's actually two
+ * iovecs, but we pack them into one and note how many of each there were.
+ *
+ * This function returns the descriptor number found, or vq->num (which is
+ * never a valid descriptor number) if none was found. A negative code is
+ * returned on error. */
+int vhost_get_vq_desc_batch(struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num)
+{
+ int ret = fetch_descs(vq);
+ int i;
+
+ if (ret)
+ return ret;
+
+ /* Now convert to IOV */
+ /* When we start there are none of either input nor output. */
+ *out_num = *in_num = 0;
+ if (unlikely(log))
+ *log_num = 0;
+
+ for (i = 0; i < vq->ndescs; ++i) {
+ unsigned iov_count = *in_num + *out_num;
+ struct vhost_desc *desc = &vq->descs[i];
+ int access;
+
+ if (desc->flags & ~VHOST_DESC_FLAGS) {
+ vq_err(vq, "Unexpected flags: 0x%x at descriptor id 0x%x\n",
+ desc->flags, desc->id);
+ ret = -EINVAL;
+ goto err;
+ }
+ if (desc->flags & VRING_DESC_F_WRITE)
+ access = VHOST_ACCESS_WO;
+ else
+ access = VHOST_ACCESS_RO;
+ ret = translate_desc(vq, desc->addr,
+ desc->len, iov + iov_count,
+ iov_size - iov_count, access);
+ if (unlikely(ret < 0)) {
+ if (ret != -EAGAIN)
+ vq_err(vq, "Translation failure %d descriptor idx %d\n",
+ ret, i);
+ goto err;
+ }
+ if (access == VHOST_ACCESS_WO) {
+ /* If this is an input descriptor,
+ * increment that count. */
+ *in_num += ret;
+ if (unlikely(log && ret)) {
+ log[*log_num].addr = desc->addr;
+ log[*log_num].len = desc->len;
+ ++*log_num;
+ }
+ } else {
+ /* If it's an output descriptor, they're all supposed
+ * to come before any input descriptors. */
+ if (unlikely(*in_num)) {
+ vq_err(vq, "Descriptor has out after in: "
+ "idx %d\n", i);
+ ret = -EINVAL;
+ goto err;
+ }
+ *out_num += ret;
+ }
+
+ ret = desc->id;
+ }
+
+ vq->ndescs = 0;
+
+ return ret;
+
+err:
+ vhost_discard_vq_desc(vq, 1);
+ vq->ndescs = 0;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vhost_get_vq_desc_batch);
+
/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
{
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index b77203e0cae2..a6fc11797a8a 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -80,6 +80,13 @@ enum vhost_uaddr_type {
VHOST_NUM_ADDRS = 3,
};
+struct vhost_desc {
+ u64 addr;
+ u32 len;
+ u16 flags; /* VRING_DESC_F_WRITE, VRING_DESC_F_NEXT */
+ u16 id;
+};
+
/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
struct vhost_dev *dev;
@@ -90,6 +97,11 @@ struct vhost_virtqueue {
struct vring_desc __user *desc;
struct vring_avail __user *avail;
struct vring_used __user *used;
+
+ struct vhost_desc *descs;
+ int ndescs;
+ int max_descs;
+
const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
struct file *kick;
struct eventfd_ctx *call_ctx;
@@ -191,6 +203,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
bool vhost_log_access_ok(struct vhost_dev *);
+int vhost_get_vq_desc_batch(struct vhost_virtqueue *,
+ struct iovec iov[], unsigned int iov_count,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num);
int vhost_get_vq_desc(struct vhost_virtqueue *,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 3/8] vhost: use batched version by default
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
2020-03-31 19:27 ` [PATCH v3 1/8] vhost: Create accessors for virtqueues private_data Eugenio Pérez
2020-03-31 19:27 ` [PATCH v3 2/8] vhost: option to fetch descriptors through an independent struct Eugenio Pérez
@ 2020-03-31 19:27 ` Eugenio Pérez
2020-03-31 19:28 ` [PATCH v3 4/8] vhost: batching fetches Eugenio Pérez
` (6 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:27 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
From: "Michael S. Tsirkin" <mst@redhat.com>
As testing shows no performance change, switch to that now.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/vhost.c | 251 +-----------------------------------------
drivers/vhost/vhost.h | 4 -
2 files changed, 2 insertions(+), 253 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 38e65a36465b..56c5253056ee 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2113,253 +2113,6 @@ static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc)
return next;
}
-static int get_indirect(struct vhost_virtqueue *vq,
- struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num,
- struct vring_desc *indirect)
-{
- struct vring_desc desc;
- unsigned int i = 0, count, found = 0;
- u32 len = vhost32_to_cpu(vq, indirect->len);
- struct iov_iter from;
- int ret, access;
-
- /* Sanity check */
- if (unlikely(len % sizeof desc)) {
- vq_err(vq, "Invalid length in indirect descriptor: "
- "len 0x%llx not multiple of 0x%zx\n",
- (unsigned long long)len,
- sizeof desc);
- return -EINVAL;
- }
-
- ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect,
- UIO_MAXIOV, VHOST_ACCESS_RO);
- if (unlikely(ret < 0)) {
- if (ret != -EAGAIN)
- vq_err(vq, "Translation failure %d in indirect.\n", ret);
- return ret;
- }
- iov_iter_init(&from, READ, vq->indirect, ret, len);
-
- /* We will use the result as an address to read from, so most
- * architectures only need a compiler barrier here. */
- read_barrier_depends();
-
- count = len / sizeof desc;
- /* Buffers are chained via a 16 bit next field, so
- * we can have at most 2^16 of these. */
- if (unlikely(count > USHRT_MAX + 1)) {
- vq_err(vq, "Indirect buffer length too big: %d\n",
- indirect->len);
- return -E2BIG;
- }
-
- do {
- unsigned iov_count = *in_num + *out_num;
- if (unlikely(++found > count)) {
- vq_err(vq, "Loop detected: last one at %u "
- "indirect size %u\n",
- i, count);
- return -EINVAL;
- }
- if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) {
- vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
- i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
- return -EINVAL;
- }
- if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) {
- vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
- i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc);
- return -EINVAL;
- }
-
- if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
- access = VHOST_ACCESS_WO;
- else
- access = VHOST_ACCESS_RO;
-
- ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
- vhost32_to_cpu(vq, desc.len), iov + iov_count,
- iov_size - iov_count, access);
- if (unlikely(ret < 0)) {
- if (ret != -EAGAIN)
- vq_err(vq, "Translation failure %d indirect idx %d\n",
- ret, i);
- return ret;
- }
- /* If this is an input descriptor, increment that count. */
- if (access == VHOST_ACCESS_WO) {
- *in_num += ret;
- if (unlikely(log && ret)) {
- log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
- log[*log_num].len = vhost32_to_cpu(vq, desc.len);
- ++*log_num;
- }
- } else {
- /* If it's an output descriptor, they're all supposed
- * to come before any input descriptors. */
- if (unlikely(*in_num)) {
- vq_err(vq, "Indirect descriptor "
- "has out after in: idx %d\n", i);
- return -EINVAL;
- }
- *out_num += ret;
- }
- } while ((i = next_desc(vq, &desc)) != -1);
- return 0;
-}
-
-/* This looks in the virtqueue and for the first available buffer, and converts
- * it to an iovec for convenient access. Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function returns the descriptor number found, or vq->num (which is
- * never a valid descriptor number) if none was found. A negative code is
- * returned on error. */
-int vhost_get_vq_desc(struct vhost_virtqueue *vq,
- struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num)
-{
- struct vring_desc desc;
- unsigned int i, head, found = 0;
- u16 last_avail_idx;
- __virtio16 avail_idx;
- __virtio16 ring_head;
- int ret, access;
-
- /* Check it isn't doing very strange things with descriptor numbers. */
- last_avail_idx = vq->last_avail_idx;
-
- if (vq->avail_idx == vq->last_avail_idx) {
- if (unlikely(vhost_get_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();
- }
-
- /* Grab the next descriptor number they're advertising, and increment
- * the index we've seen. */
- if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) {
- vq_err(vq, "Failed to read head: idx %d address %p\n",
- last_avail_idx,
- &vq->avail->ring[last_avail_idx % vq->num]);
- return -EFAULT;
- }
-
- head = vhost16_to_cpu(vq, ring_head);
-
- /* If their number is silly, that's an error. */
- if (unlikely(head >= vq->num)) {
- vq_err(vq, "Guest says index %u > %u is available",
- head, vq->num);
- return -EINVAL;
- }
-
- /* When we start there are none of either input nor output. */
- *out_num = *in_num = 0;
- if (unlikely(log))
- *log_num = 0;
-
- i = head;
- do {
- unsigned iov_count = *in_num + *out_num;
- if (unlikely(i >= vq->num)) {
- vq_err(vq, "Desc index is %u > %u, head = %u",
- i, vq->num, head);
- return -EINVAL;
- }
- if (unlikely(++found > vq->num)) {
- vq_err(vq, "Loop detected: last one at %u "
- "vq size %u head %u\n",
- i, vq->num, head);
- return -EINVAL;
- }
- ret = vhost_get_desc(vq, &desc, i);
- if (unlikely(ret)) {
- vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
- i, vq->desc + i);
- return -EFAULT;
- }
- if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) {
- ret = get_indirect(vq, iov, iov_size,
- out_num, in_num,
- log, log_num, &desc);
- if (unlikely(ret < 0)) {
- if (ret != -EAGAIN)
- vq_err(vq, "Failure detected "
- "in indirect descriptor at idx %d\n", i);
- return ret;
- }
- continue;
- }
-
- if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE))
- access = VHOST_ACCESS_WO;
- else
- access = VHOST_ACCESS_RO;
- ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr),
- vhost32_to_cpu(vq, desc.len), iov + iov_count,
- iov_size - iov_count, access);
- if (unlikely(ret < 0)) {
- if (ret != -EAGAIN)
- vq_err(vq, "Translation failure %d descriptor idx %d\n",
- ret, i);
- return ret;
- }
- if (access == VHOST_ACCESS_WO) {
- /* If this is an input descriptor,
- * increment that count. */
- *in_num += ret;
- if (unlikely(log && ret)) {
- log[*log_num].addr = vhost64_to_cpu(vq, desc.addr);
- log[*log_num].len = vhost32_to_cpu(vq, desc.len);
- ++*log_num;
- }
- } else {
- /* If it's an output descriptor, they're all supposed
- * to come before any input descriptors. */
- if (unlikely(*in_num)) {
- vq_err(vq, "Descriptor has out after in: "
- "idx %d\n", i);
- return -EINVAL;
- }
- *out_num += ret;
- }
- } while ((i = next_desc(vq, &desc)) != -1);
-
- /* On success, increment avail index. */
- vq->last_avail_idx++;
-
- /* Assume notifications from guest are disabled at this point,
- * if they aren't we would need to update avail_event index. */
- BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY));
- return head;
-}
-EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
-
static struct vhost_desc *peek_split_desc(struct vhost_virtqueue *vq)
{
BUG_ON(!vq->ndescs);
@@ -2570,7 +2323,7 @@ static int fetch_descs(struct vhost_virtqueue *vq)
* This function returns the descriptor number found, or vq->num (which is
* never a valid descriptor number) if none was found. A negative code is
* returned on error. */
-int vhost_get_vq_desc_batch(struct vhost_virtqueue *vq,
+int vhost_get_vq_desc(struct vhost_virtqueue *vq,
struct iovec iov[], unsigned int iov_size,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num)
@@ -2645,7 +2398,7 @@ int vhost_get_vq_desc_batch(struct vhost_virtqueue *vq,
return ret;
}
-EXPORT_SYMBOL_GPL(vhost_get_vq_desc_batch);
+EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n)
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a6fc11797a8a..1dbb5e44fba4 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -203,10 +203,6 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
bool vhost_log_access_ok(struct vhost_dev *);
-int vhost_get_vq_desc_batch(struct vhost_virtqueue *,
- struct iovec iov[], unsigned int iov_count,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num);
int vhost_get_vq_desc(struct vhost_virtqueue *,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 4/8] vhost: batching fetches
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (2 preceding siblings ...)
2020-03-31 19:27 ` [PATCH v3 3/8] vhost: use batched version by default Eugenio Pérez
@ 2020-03-31 19:28 ` Eugenio Pérez
2020-03-31 19:28 ` [PATCH v3 5/8] tools/virtio: Add --batch option Eugenio Pérez
` (5 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:28 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
From: "Michael S. Tsirkin" <mst@redhat.com>
With this patch applied, new and old code perform identically.
Lots of extra optimizations are now possible, e.g.
we can fetch multiple heads with copy_from/to_user now.
We can get rid of maintaining the log array. Etc etc.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/test.c | 2 +-
drivers/vhost/vhost.c | 47 ++++++++++++++++++++++++++++++++++++++-----
drivers/vhost/vhost.h | 5 ++++-
3 files changed, 47 insertions(+), 7 deletions(-)
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index 394e2e5c772d..4b00cd4266ad 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -119,7 +119,7 @@ static int vhost_test_open(struct inode *inode, struct file *f)
dev = &n->dev;
vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
- vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
+ vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV + 64,
VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT);
f->private_data = n;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 56c5253056ee..1646b1ce312a 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -303,6 +303,7 @@ static void vhost_vq_reset(struct vhost_dev *dev,
{
vq->num = 1;
vq->ndescs = 0;
+ vq->first_desc = 0;
vq->desc = NULL;
vq->avail = NULL;
vq->used = NULL;
@@ -371,6 +372,11 @@ static int vhost_worker(void *data)
return 0;
}
+static int vhost_vq_num_batch_descs(struct vhost_virtqueue *vq)
+{
+ return vq->max_descs - UIO_MAXIOV;
+}
+
static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
{
kfree(vq->descs);
@@ -393,6 +399,9 @@ static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
for (i = 0; i < dev->nvqs; ++i) {
vq = dev->vqs[i];
vq->max_descs = dev->iov_limit;
+ if (vhost_vq_num_batch_descs(vq) < 0) {
+ return -EINVAL;
+ }
vq->descs = kmalloc_array(vq->max_descs,
sizeof(*vq->descs),
GFP_KERNEL);
@@ -1643,6 +1652,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
vq->last_avail_idx = s.num;
/* Forget the cached index value. */
vq->avail_idx = vq->last_avail_idx;
+ vq->ndescs = vq->first_desc = 0;
break;
case VHOST_GET_VRING_BASE:
s.index = idx;
@@ -2211,7 +2221,7 @@ static int fetch_indirect_descs(struct vhost_virtqueue *vq,
return 0;
}
-static int fetch_descs(struct vhost_virtqueue *vq)
+static int fetch_buf(struct vhost_virtqueue *vq)
{
unsigned int i, head, found = 0;
struct vhost_desc *last;
@@ -2224,7 +2234,11 @@ static int fetch_descs(struct vhost_virtqueue *vq)
/* Check it isn't doing very strange things with descriptor numbers. */
last_avail_idx = vq->last_avail_idx;
- if (vq->avail_idx == vq->last_avail_idx) {
+ if (unlikely(vq->avail_idx == vq->last_avail_idx)) {
+ /* If we already have work to do, don't bother re-checking. */
+ if (likely(vq->ndescs))
+ return vq->num;
+
if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) {
vq_err(vq, "Failed to access avail idx at %p\n",
&vq->avail->idx);
@@ -2315,6 +2329,24 @@ static int fetch_descs(struct vhost_virtqueue *vq)
return 0;
}
+static int fetch_descs(struct vhost_virtqueue *vq)
+{
+ int ret = 0;
+
+ if (unlikely(vq->first_desc >= vq->ndescs)) {
+ vq->first_desc = 0;
+ vq->ndescs = 0;
+ }
+
+ if (vq->ndescs)
+ return 0;
+
+ while (!ret && vq->ndescs <= vhost_vq_num_batch_descs(vq))
+ ret = fetch_buf(vq);
+
+ return vq->ndescs ? 0 : ret;
+}
+
/* This looks in the virtqueue and for the first available buffer, and converts
* it to an iovec for convenient access. Since descriptors consist of some
* number of output then some number of input descriptors, it's actually two
@@ -2340,7 +2372,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
if (unlikely(log))
*log_num = 0;
- for (i = 0; i < vq->ndescs; ++i) {
+ for (i = vq->first_desc; i < vq->ndescs; ++i) {
unsigned iov_count = *in_num + *out_num;
struct vhost_desc *desc = &vq->descs[i];
int access;
@@ -2386,14 +2418,19 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
}
ret = desc->id;
+
+ if (!(desc->flags & VRING_DESC_F_NEXT))
+ break;
}
- vq->ndescs = 0;
+ vq->first_desc = i + 1;
return ret;
err:
- vhost_discard_vq_desc(vq, 1);
+ for (i = vq->first_desc; i < vq->ndescs; ++i)
+ if (!(vq->descs[i].flags & VRING_DESC_F_NEXT))
+ vhost_discard_vq_desc(vq, 1);
vq->ndescs = 0;
return ret;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 1dbb5e44fba4..e1caca605c56 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -100,6 +100,7 @@ struct vhost_virtqueue {
struct vhost_desc *descs;
int ndescs;
+ int first_desc;
int max_descs;
const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
@@ -242,7 +243,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
#define vq_err(vq, fmt, ...) do { \
- pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
+ pr_err(pr_fmt(fmt), ##__VA_ARGS__); \
if ((vq)->error_ctx) \
eventfd_signal((vq)->error_ctx, 1);\
} while (0)
@@ -268,6 +269,8 @@ static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
void *private_data)
{
vq->private_data = private_data;
+ vq->ndescs = 0;
+ vq->first_desc = 0;
}
/**
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 5/8] tools/virtio: Add --batch option
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (3 preceding siblings ...)
2020-03-31 19:28 ` [PATCH v3 4/8] vhost: batching fetches Eugenio Pérez
@ 2020-03-31 19:28 ` Eugenio Pérez
2020-03-31 19:28 ` [PATCH v3 6/8] tools/virtio: Add --batch=random option Eugenio Pérez
` (4 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:28 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
This allow to test vhost having >1 buffers in flight
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
tools/virtio/virtio_test.c | 47 ++++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 10 deletions(-)
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index b427def67e7e..c30de9088f3c 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <getopt.h>
+#include <limits.h>
#include <string.h>
#include <poll.h>
#include <sys/eventfd.h>
@@ -152,11 +153,11 @@ static void wait_for_interrupt(struct vdev_info *dev)
}
static void run_test(struct vdev_info *dev, struct vq_info *vq,
- bool delayed, int bufs)
+ bool delayed, int batch, int bufs)
{
struct scatterlist sl;
long started = 0, completed = 0;
- long completed_before;
+ long completed_before, started_before;
int r, test = 1;
unsigned len;
long long spurious = 0;
@@ -165,28 +166,42 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
for (;;) {
virtqueue_disable_cb(vq->vq);
completed_before = completed;
+ started_before = started;
do {
- if (started < bufs) {
+ while (started < bufs &&
+ (started - completed) < batch) {
sg_init_one(&sl, dev->buf, dev->buf_size);
r = virtqueue_add_outbuf(vq->vq, &sl, 1,
dev->buf + started,
GFP_ATOMIC);
- if (likely(r == 0)) {
- ++started;
- if (unlikely(!virtqueue_kick(vq->vq)))
+ if (unlikely(r != 0)) {
+ if (r == -ENOSPC &&
+ started > started_before)
+ r = 0;
+ else
r = -1;
+ break;
}
- } else
+
+ ++started;
+
+ if (unlikely(!virtqueue_kick(vq->vq))) {
+ r = -1;
+ break;
+ }
+ }
+
+ if (started >= bufs)
r = -1;
/* Flush out completed bufs if any */
- if (virtqueue_get_buf(vq->vq, &len)) {
+ while (virtqueue_get_buf(vq->vq, &len)) {
++completed;
r = 0;
}
} while (r == 0);
- if (completed == completed_before)
+ if (completed == completed_before && started == started_before)
++spurious;
assert(completed <= bufs);
assert(started <= bufs);
@@ -244,6 +259,11 @@ const struct option longopts[] = {
.name = "no-delayed-interrupt",
.val = 'd',
},
+ {
+ .name = "batch",
+ .val = 'b',
+ .has_arg = required_argument,
+ },
{
}
};
@@ -255,6 +275,7 @@ static void help(void)
" [--no-event-idx]"
" [--no-virtio-1]"
" [--delayed-interrupt]"
+ " [--batch=N]"
"\n");
}
@@ -263,6 +284,7 @@ int main(int argc, char **argv)
struct vdev_info dev;
unsigned long long features = (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
(1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VIRTIO_F_VERSION_1);
+ long batch = 1;
int o;
bool delayed = false;
@@ -289,6 +311,11 @@ int main(int argc, char **argv)
case 'D':
delayed = true;
break;
+ case 'b':
+ batch = strtol(optarg, NULL, 10);
+ assert(batch > 0);
+ assert(batch < (long)INT_MAX + 1);
+ break;
default:
assert(0);
break;
@@ -298,6 +325,6 @@ int main(int argc, char **argv)
done:
vdev_info_init(&dev, features);
vq_info_add(&dev, 256);
- run_test(&dev, &dev.vqs[0], delayed, 0x100000);
+ run_test(&dev, &dev.vqs[0], delayed, batch, 0x100000);
return 0;
}
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 6/8] tools/virtio: Add --batch=random option
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (4 preceding siblings ...)
2020-03-31 19:28 ` [PATCH v3 5/8] tools/virtio: Add --batch option Eugenio Pérez
@ 2020-03-31 19:28 ` Eugenio Pérez
2020-03-31 19:28 ` [PATCH v3 7/8] tools/virtio: Add --reset=random Eugenio Pérez
` (3 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:28 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
So we can test with non-deterministic batches in flight.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
tools/virtio/virtio_test.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index c30de9088f3c..4a2b9d11f287 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -19,6 +19,8 @@
#include <linux/virtio_ring.h>
#include "../../drivers/vhost/test.h"
+#define RANDOM_BATCH -1
+
/* Unused */
void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
@@ -161,6 +163,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
int r, test = 1;
unsigned len;
long long spurious = 0;
+ const bool random_batch = batch == RANDOM_BATCH;
r = ioctl(dev->control, VHOST_TEST_RUN, &test);
assert(r >= 0);
for (;;) {
@@ -168,6 +171,9 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
completed_before = completed;
started_before = started;
do {
+ if (random_batch)
+ batch = (random() % vq->vring.num) + 1;
+
while (started < bufs &&
(started - completed) < batch) {
sg_init_one(&sl, dev->buf, dev->buf_size);
@@ -275,7 +281,7 @@ static void help(void)
" [--no-event-idx]"
" [--no-virtio-1]"
" [--delayed-interrupt]"
- " [--batch=N]"
+ " [--batch=random/N]"
"\n");
}
@@ -312,9 +318,13 @@ int main(int argc, char **argv)
delayed = true;
break;
case 'b':
- batch = strtol(optarg, NULL, 10);
- assert(batch > 0);
- assert(batch < (long)INT_MAX + 1);
+ if (0 == strcmp(optarg, "random")) {
+ batch = RANDOM_BATCH;
+ } else {
+ batch = strtol(optarg, NULL, 10);
+ assert(batch > 0);
+ assert(batch < (long)INT_MAX + 1);
+ }
break;
default:
assert(0);
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 7/8] tools/virtio: Add --reset=random
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (5 preceding siblings ...)
2020-03-31 19:28 ` [PATCH v3 6/8] tools/virtio: Add --batch=random option Eugenio Pérez
@ 2020-03-31 19:28 ` Eugenio Pérez
2020-03-31 19:28 ` [PATCH v3 8/8] tools/virtio: Make --reset reset ring idx Eugenio Pérez
` (2 subsequent siblings)
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:28 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
Currently, it only removes and add backend, but it will reset vq
position in future commits.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/vhost/test.c | 57 ++++++++++++++++++++++++++++++++++++++
drivers/vhost/test.h | 1 +
tools/virtio/virtio_test.c | 44 ++++++++++++++++++++++++++---
3 files changed, 98 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index 4b00cd4266ad..102066515b48 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -263,9 +263,62 @@ static int vhost_test_set_features(struct vhost_test *n, u64 features)
return 0;
}
+static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd)
+{
+ static void *private_data;
+
+ const bool enable = fd != -1;
+ struct vhost_virtqueue *vq;
+ int r;
+
+ mutex_lock(&n->dev.mutex);
+ r = vhost_dev_check_owner(&n->dev);
+ if (r)
+ goto err;
+
+ if (index >= VHOST_TEST_VQ_MAX) {
+ r = -ENOBUFS;
+ goto err;
+ }
+ vq = &n->vqs[index];
+ mutex_lock(&vq->mutex);
+
+ /* Verify that ring has been setup correctly. */
+ if (!vhost_vq_access_ok(vq)) {
+ r = -EFAULT;
+ goto err_vq;
+ }
+ if (!enable) {
+ vhost_poll_stop(&vq->poll);
+ private_data = vq->private_data;
+ vq->private_data = NULL;
+ } else {
+ r = vhost_vq_init_access(vq);
+ vq->private_data = private_data;
+ if (r == 0)
+ r = vhost_poll_start(&vq->poll, vq->kick);
+ }
+
+ mutex_unlock(&vq->mutex);
+
+ if (enable) {
+ vhost_test_flush_vq(n, index);
+ }
+
+ mutex_unlock(&n->dev.mutex);
+ return 0;
+
+err_vq:
+ mutex_unlock(&vq->mutex);
+err:
+ mutex_unlock(&n->dev.mutex);
+ return r;
+}
+
static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
unsigned long arg)
{
+ struct vhost_vring_file backend;
struct vhost_test *n = f->private_data;
void __user *argp = (void __user *)arg;
u64 __user *featurep = argp;
@@ -277,6 +330,10 @@ static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
if (copy_from_user(&test, argp, sizeof test))
return -EFAULT;
return vhost_test_run(n, test);
+ case VHOST_TEST_SET_BACKEND:
+ if (copy_from_user(&backend, argp, sizeof backend))
+ return -EFAULT;
+ return vhost_test_set_backend(n, backend.index, backend.fd);
case VHOST_GET_FEATURES:
features = VHOST_FEATURES;
if (copy_to_user(featurep, &features, sizeof features))
diff --git a/drivers/vhost/test.h b/drivers/vhost/test.h
index 7dd265bfdf81..822bc4bee03a 100644
--- a/drivers/vhost/test.h
+++ b/drivers/vhost/test.h
@@ -4,5 +4,6 @@
/* Start a given test on the virtio null device. 0 stops all tests. */
#define VHOST_TEST_RUN _IOW(VHOST_VIRTIO, 0x31, int)
+#define VHOST_TEST_SET_BACKEND _IOW(VHOST_VIRTIO, 0x32, int)
#endif
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index 4a2b9d11f287..93d81cd64ba0 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -20,6 +20,7 @@
#include "../../drivers/vhost/test.h"
#define RANDOM_BATCH -1
+#define RANDOM_RESET -1
/* Unused */
void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
@@ -46,6 +47,9 @@ struct vdev_info {
struct vhost_memory *mem;
};
+static const struct vhost_vring_file no_backend = { .fd = -1 },
+ backend = { .fd = 1 };
+
bool vq_notify(struct virtqueue *vq)
{
struct vq_info *info = vq->priv;
@@ -155,10 +159,10 @@ static void wait_for_interrupt(struct vdev_info *dev)
}
static void run_test(struct vdev_info *dev, struct vq_info *vq,
- bool delayed, int batch, int bufs)
+ bool delayed, int batch, int reset_n, int bufs)
{
struct scatterlist sl;
- long started = 0, completed = 0;
+ long started = 0, completed = 0, next_reset = reset_n;
long completed_before, started_before;
int r, test = 1;
unsigned len;
@@ -171,6 +175,7 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
completed_before = completed;
started_before = started;
do {
+ const bool reset = reset_n && completed > next_reset;
if (random_batch)
batch = (random() % vq->vring.num) + 1;
@@ -200,12 +205,26 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
if (started >= bufs)
r = -1;
+ if (reset) {
+ r = ioctl(dev->control, VHOST_TEST_SET_BACKEND,
+ &no_backend);
+ assert(!r);
+ }
+
/* Flush out completed bufs if any */
while (virtqueue_get_buf(vq->vq, &len)) {
++completed;
r = 0;
}
+ if (reset) {
+ r = ioctl(dev->control, VHOST_TEST_SET_BACKEND,
+ &backend);
+ assert(!r);
+
+ while (completed > next_reset)
+ next_reset += completed;
+ }
} while (r == 0);
if (completed == completed_before && started == started_before)
++spurious;
@@ -270,6 +289,11 @@ const struct option longopts[] = {
.val = 'b',
.has_arg = required_argument,
},
+ {
+ .name = "reset",
+ .val = 'r',
+ .has_arg = optional_argument,
+ },
{
}
};
@@ -282,6 +306,7 @@ static void help(void)
" [--no-virtio-1]"
" [--delayed-interrupt]"
" [--batch=random/N]"
+ " [--reset=random/N]"
"\n");
}
@@ -290,7 +315,7 @@ int main(int argc, char **argv)
struct vdev_info dev;
unsigned long long features = (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
(1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VIRTIO_F_VERSION_1);
- long batch = 1;
+ long batch = 1, reset = 0;
int o;
bool delayed = false;
@@ -326,6 +351,17 @@ int main(int argc, char **argv)
assert(batch < (long)INT_MAX + 1);
}
break;
+ case 'r':
+ if (!optarg) {
+ reset = 1;
+ } else if (0 == strcmp(optarg, "random")) {
+ reset = RANDOM_RESET;
+ } else {
+ reset = strtol(optarg, NULL, 10);
+ assert(reset >= 0);
+ assert(reset < (long)INT_MAX + 1);
+ }
+ break;
default:
assert(0);
break;
@@ -335,6 +371,6 @@ int main(int argc, char **argv)
done:
vdev_info_init(&dev, features);
vq_info_add(&dev, 256);
- run_test(&dev, &dev.vqs[0], delayed, batch, 0x100000);
+ run_test(&dev, &dev.vqs[0], delayed, batch, reset, 0x100000);
return 0;
}
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* [PATCH v3 8/8] tools/virtio: Make --reset reset ring idx
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (6 preceding siblings ...)
2020-03-31 19:28 ` [PATCH v3 7/8] tools/virtio: Add --reset=random Eugenio Pérez
@ 2020-03-31 19:28 ` Eugenio Pérez
2020-03-31 19:51 ` [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Michael S. Tsirkin
2020-04-01 7:19 ` Christian Borntraeger
9 siblings, 0 replies; 15+ messages in thread
From: Eugenio Pérez @ 2020-03-31 19:28 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Eugenio Pérez,
Christian Borntraeger, Halil Pasic, Cornelia Huck
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
drivers/virtio/virtio_ring.c | 29 +++++++++++++++++++++++++++++
tools/virtio/linux/virtio.h | 2 ++
tools/virtio/virtio_test.c | 28 +++++++++++++++++++++++++++-
3 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 867c7ebd3f10..01b322ee2e04 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1810,6 +1810,35 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
+#ifndef __KERNEL__
+
+/**
+ * virtqueue_reset_free_head - Reset to 0 the members of split ring.
+ * @vq: Virtqueue to reset.
+ *
+ * At this moment, is only meant for debug the ring index change, do not use
+ * in production.
+ */
+void virtqueue_reset_free_head(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ // vq->last_used_idx = 0;
+ vq->num_added = 0;
+
+ vq->split.queue_size_in_bytes = 0;
+ vq->split.avail_flags_shadow = 0;
+ vq->split.avail_idx_shadow = 0;
+
+ memset(vq->split.desc_state, 0, vq->split.vring.num *
+ sizeof(struct vring_desc_state_split));
+
+ vq->free_head = 0;
+}
+EXPORT_SYMBOL_GPL(virtqueue_reset_free_head);
+
+#endif
+
/**
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @_vq: the struct virtqueue
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
index b751350d4ce8..5d33eab6b814 100644
--- a/tools/virtio/linux/virtio.h
+++ b/tools/virtio/linux/virtio.h
@@ -65,4 +65,6 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
const char *name);
void vring_del_virtqueue(struct virtqueue *vq);
+void virtqueue_reset_free_head(struct virtqueue *vq);
+
#endif
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index 93d81cd64ba0..bf21ece30594 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -49,6 +49,7 @@ struct vdev_info {
static const struct vhost_vring_file no_backend = { .fd = -1 },
backend = { .fd = 1 };
+static const struct vhost_vring_state null_state = {};
bool vq_notify(struct virtqueue *vq)
{
@@ -218,10 +219,33 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
}
if (reset) {
+ struct vhost_vring_state s = { .index = 0 };
+ int i;
+ vq->vring.avail->idx = 0;
+ vq->vq->num_free = vq->vring.num;
+
+ // Put everything in free lists.
+ for (i = 0; i < vq->vring.num-1; i++)
+ vq->vring.desc[i].next =
+ cpu_to_virtio16(&dev->vdev,
+ i + 1);
+ vq->vring.desc[vq->vring.num-1].next = 0;
+ virtqueue_reset_free_head(vq->vq);
+
+ r = ioctl(dev->control, VHOST_GET_VRING_BASE,
+ &s);
+ assert(!r);
+
+ s.num = 0;
+ r = ioctl(dev->control, VHOST_SET_VRING_BASE,
+ &null_state);
+ assert(!r);
+
r = ioctl(dev->control, VHOST_TEST_SET_BACKEND,
&backend);
assert(!r);
+ started = completed;
while (completed > next_reset)
next_reset += completed;
}
@@ -243,7 +267,9 @@ static void run_test(struct vdev_info *dev, struct vq_info *vq,
test = 0;
r = ioctl(dev->control, VHOST_TEST_RUN, &test);
assert(r >= 0);
- fprintf(stderr, "spurious wakeups: 0x%llx\n", spurious);
+ fprintf(stderr,
+ "spurious wakeups: 0x%llx started=0x%lx completed=0x%lx\n",
+ spurious, started, completed);
}
const char optstring[] = "h";
--
2.18.1
^ permalink raw reply related [flat|nested] 15+ messages in thread* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (7 preceding siblings ...)
2020-03-31 19:28 ` [PATCH v3 8/8] tools/virtio: Make --reset reset ring idx Eugenio Pérez
@ 2020-03-31 19:51 ` Michael S. Tsirkin
2020-04-01 7:19 ` Christian Borntraeger
9 siblings, 0 replies; 15+ messages in thread
From: Michael S. Tsirkin @ 2020-03-31 19:51 UTC (permalink / raw)
To: Eugenio Pérez
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Christian Borntraeger,
Halil Pasic, Cornelia Huck
On Tue, Mar 31, 2020 at 09:27:56PM +0200, Eugenio Pérez wrote:
> Vhost did not reset properly the batched descriptors on SET_VRING_BASE
> event. Because of that, is possible to return an invalid descriptor to
> the guest.
>
> This series ammend this, resetting them every time backend changes, and
> creates a test to assert correct behavior. To do that, they need to
> expose a new function in virtio_ring, virtqueue_reset_free_head, only
> on test code.
>
> Another useful thing would be to check if mutex is properly get in
> vq private_data accessors. Not sure if mutex debug code allow that,
> similar to C++ unique lock::owns_lock. Not acquiring in the function
> because caller code holds the mutex in order to perform more actions.
I pushed vhost branch with patch 1, pls send patches on top of that!
> v3:
> * Rename accesors functions.
> * Make scsi and test use the accesors too.
>
> v2:
> * Squashed commits.
> * Create vq private_data accesors (mst).
>
> This is meant to be applied on top of
> c4f1c41a6094582903c75c0dcfacb453c959d457 in
> git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git.
>
> Eugenio Pérez (5):
> vhost: Create accessors for virtqueues private_data
> tools/virtio: Add --batch option
> tools/virtio: Add --batch=random option
> tools/virtio: Add --reset=random
> tools/virtio: Make --reset reset ring idx
>
> Michael S. Tsirkin (3):
> vhost: option to fetch descriptors through an independent struct
> vhost: use batched version by default
> vhost: batching fetches
>
> drivers/vhost/net.c | 28 ++--
> drivers/vhost/scsi.c | 14 +-
> drivers/vhost/test.c | 69 ++++++++-
> drivers/vhost/test.h | 1 +
> drivers/vhost/vhost.c | 271 +++++++++++++++++++++++------------
> drivers/vhost/vhost.h | 44 +++++-
> drivers/vhost/vsock.c | 14 +-
> drivers/virtio/virtio_ring.c | 29 ++++
> tools/virtio/linux/virtio.h | 2 +
> tools/virtio/virtio_test.c | 123 ++++++++++++++--
> 10 files changed, 456 insertions(+), 139 deletions(-)
>
> --
> 2.18.1
^ permalink raw reply [flat|nested] 15+ messages in thread* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-03-31 19:27 [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Eugenio Pérez
` (8 preceding siblings ...)
2020-03-31 19:51 ` [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call Michael S. Tsirkin
@ 2020-04-01 7:19 ` Christian Borntraeger
2020-04-01 18:40 ` Eugenio Perez Martin
9 siblings, 1 reply; 15+ messages in thread
From: Christian Borntraeger @ 2020-04-01 7:19 UTC (permalink / raw)
To: Eugenio Pérez, Michael S. Tsirkin
Cc: linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Halil Pasic,
Cornelia Huck
On 31.03.20 21:27, Eugenio Pérez wrote:
> Vhost did not reset properly the batched descriptors on SET_VRING_BASE
> event. Because of that, is possible to return an invalid descriptor to
> the guest.
>
> This series ammend this, resetting them every time backend changes, and
> creates a test to assert correct behavior. To do that, they need to
> expose a new function in virtio_ring, virtqueue_reset_free_head, only
> on test code.
>
> Another useful thing would be to check if mutex is properly get in
> vq private_data accessors. Not sure if mutex debug code allow that,
> similar to C++ unique lock::owns_lock. Not acquiring in the function
> because caller code holds the mutex in order to perform more actions.
>
> v3:
> * Rename accesors functions.
> * Make scsi and test use the accesors too.
>
> v2:
> * Squashed commits.
> * Create vq private_data accesors (mst).
>
> This is meant to be applied on top of
> c4f1c41a6094582903c75c0dcfacb453c959d457 in
> git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git.
A quick test on s390 looks good.
^ permalink raw reply [flat|nested] 15+ messages in thread* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-04-01 7:19 ` Christian Borntraeger
@ 2020-04-01 18:40 ` Eugenio Perez Martin
2020-04-01 18:44 ` Christian Borntraeger
0 siblings, 1 reply; 15+ messages in thread
From: Eugenio Perez Martin @ 2020-04-01 18:40 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Michael S. Tsirkin, linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Halil Pasic,
Cornelia Huck
On Wed, Apr 1, 2020 at 9:19 AM Christian Borntraeger
<borntraeger@de.ibm.com> wrote:
>
> On 31.03.20 21:27, Eugenio Pérez wrote:
> > Vhost did not reset properly the batched descriptors on SET_VRING_BASE
> > event. Because of that, is possible to return an invalid descriptor to
> > the guest.
> >
> > This series ammend this, resetting them every time backend changes, and
> > creates a test to assert correct behavior. To do that, they need to
> > expose a new function in virtio_ring, virtqueue_reset_free_head, only
> > on test code.
> >
> > Another useful thing would be to check if mutex is properly get in
> > vq private_data accessors. Not sure if mutex debug code allow that,
> > similar to C++ unique lock::owns_lock. Not acquiring in the function
> > because caller code holds the mutex in order to perform more actions.
>
>
>
> >
> > v3:
> > * Rename accesors functions.
> > * Make scsi and test use the accesors too.
> >
> > v2:
> > * Squashed commits.
> > * Create vq private_data accesors (mst).
> >
> > This is meant to be applied on top of
> > c4f1c41a6094582903c75c0dcfacb453c959d457 in
> > git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git.
>
>
> A quick test on s390 looks good.
>
Really good to know :).
Would it be possible to investigate when qemu launches the offending ioctls?
Thanks!
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-04-01 18:40 ` Eugenio Perez Martin
@ 2020-04-01 18:44 ` Christian Borntraeger
2020-04-01 19:13 ` Christian Borntraeger
0 siblings, 1 reply; 15+ messages in thread
From: Christian Borntraeger @ 2020-04-01 18:44 UTC (permalink / raw)
To: Eugenio Perez Martin
Cc: Michael S. Tsirkin, linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Halil Pasic,
Cornelia Huck
On 01.04.20 20:40, Eugenio Perez Martin wrote:
> On Wed, Apr 1, 2020 at 9:19 AM Christian Borntraeger
> <borntraeger@de.ibm.com> wrote:
>>
>> On 31.03.20 21:27, Eugenio Pérez wrote:
>>> Vhost did not reset properly the batched descriptors on SET_VRING_BASE
>>> event. Because of that, is possible to return an invalid descriptor to
>>> the guest.
>>>
>>> This series ammend this, resetting them every time backend changes, and
>>> creates a test to assert correct behavior. To do that, they need to
>>> expose a new function in virtio_ring, virtqueue_reset_free_head, only
>>> on test code.
>>>
>>> Another useful thing would be to check if mutex is properly get in
>>> vq private_data accessors. Not sure if mutex debug code allow that,
>>> similar to C++ unique lock::owns_lock. Not acquiring in the function
>>> because caller code holds the mutex in order to perform more actions.
>>
>>
>>
>>>
>>> v3:
>>> * Rename accesors functions.
>>> * Make scsi and test use the accesors too.
>>>
>>> v2:
>>> * Squashed commits.
>>> * Create vq private_data accesors (mst).
>>>
>>> This is meant to be applied on top of
>>> c4f1c41a6094582903c75c0dcfacb453c959d457 in
>>> git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git.
>>
>>
>> A quick test on s390 looks good.
>>
>
> Really good to know :).
>
> Would it be possible to investigate when qemu launches the offending ioctls?
During guest reboot. This is obvious, no?
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-04-01 18:44 ` Christian Borntraeger
@ 2020-04-01 19:13 ` Christian Borntraeger
2020-04-02 8:17 ` Eugenio Perez Martin
0 siblings, 1 reply; 15+ messages in thread
From: Christian Borntraeger @ 2020-04-01 19:13 UTC (permalink / raw)
To: Eugenio Perez Martin
Cc: Michael S. Tsirkin, linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Halil Pasic,
Cornelia Huck
>> Would it be possible to investigate when qemu launches the offending ioctls?
>
> During guest reboot. This is obvious, no?
>
For example during reboot we do re-setup the virt queues:
#1 0x00000000010f3e7a in vhost_kernel_set_vring_base (dev=0x21f5f30, ring=0x3ff84d74e88) at /home/cborntra/REPOS/qemu/hw/virtio/vhost-backend.c:126
#2 0x00000000010f2f92 in vhost_virtqueue_start (idx=0, vq=0x21f6180, vdev=0x241d570, dev=0x21f5f30) at /home/cborntra/REPOS/qemu/hw/virtio/vhost.c:1016
#3 vhost_dev_start (hdev=hdev@entry=0x21f5f30, vdev=vdev@entry=0x241d570) at /home/cborntra/REPOS/qemu/hw/virtio/vhost.c:1646
#4 0x00000000011c265a in vhost_net_start_one (dev=0x241d570, net=0x21f5f30) at /home/cborntra/REPOS/qemu/hw/net/vhost_net.c:236
#5 vhost_net_start (dev=dev@entry=0x241d570, ncs=0x2450f40, total_queues=total_queues@entry=1) at /home/cborntra/REPOS/qemu/hw/net/vhost_net.c:338
#6 0x00000000010cfdfe in virtio_net_vhost_status (status=15 '\017', n=0x241d570) at /home/cborntra/REPOS/qemu/hw/net/virtio-net.c:250
#7 virtio_net_set_status (vdev=0x241d570, status=<optimized out>) at /home/cborntra/REPOS/qemu/hw/net/virtio-net.c:331
#8 0x00000000010eaef4 in virtio_set_status (vdev=vdev@entry=0x241d570, val=<optimized out>) at /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1956
#9 0x000000000110ba78 in virtio_ccw_cb (sch=0x2422c30, ccw=...) at /home/cborntra/REPOS/qemu/hw/s390x/virtio-ccw.c:509
#10 0x00000000011053fc in css_interpret_ccw (sch=sch@entry=0x2422c30, ccw_addr=<optimized out>, suspend_allowed=suspend_allowed@entry=false) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1108
#11 0x000000000110557c in sch_handle_start_func_virtual (sch=0x2422c30) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1162
#12 do_subchannel_work_virtual (sch=0x2422c30) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1256
#13 0x0000000001168592 in ioinst_handle_ssch (cpu=cpu@entry=0x234b920, reg1=<optimized out>, ipb=<optimized out>, ra=ra@entry=0) at /home/cborntra/REPOS/qemu/target/s390x/ioinst.c:218
#14 0x0000000001170012 in handle_b2 (ipa1=<optimized out>, run=0x3ff97880000, cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1279
#15 handle_instruction (run=0x3ff97880000, cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1664
#16 handle_intercept (cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1747
#17 kvm_arch_handle_exit (cs=cs@entry=0x234b920, run=run@entry=0x3ff97880000) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1937
#18 0x00000000010972dc in kvm_cpu_exec (cpu=cpu@entry=0x234b920) at /home/cborntra/REPOS/qemu/accel/kvm/kvm-all.c:2445
#19 0x00000000010784f6 in qemu_kvm_cpu_thread_fn (arg=0x234b920) at /home/cborntra/REPOS/qemu/cpus.c:1246
#20 qemu_kvm_cpu_thread_fn (arg=arg@entry=0x234b920) at /home/cborntra/REPOS/qemu/cpus.c:1218
#21 0x00000000013891fa in qemu_thread_start (args=0x2372f30) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:519
#22 0x000003ff93809ed6 in start_thread () from target:/lib64/libpthread.so.0
#23 0x000003ff93705e46 in thread_start () from target:/lib64/libc.so.6
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call
2020-04-01 19:13 ` Christian Borntraeger
@ 2020-04-02 8:17 ` Eugenio Perez Martin
0 siblings, 0 replies; 15+ messages in thread
From: Eugenio Perez Martin @ 2020-04-02 8:17 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Michael S. Tsirkin, linux-kernel, Stephen Rothwell, kvm list,
Linux Next Mailing List, virtualization, Halil Pasic,
Cornelia Huck
On Wed, Apr 1, 2020 at 9:13 PM Christian Borntraeger
<borntraeger@de.ibm.com> wrote:
>
> >> Would it be possible to investigate when qemu launches the offending ioctls?
> >
> > During guest reboot. This is obvious, no?
> >
>
Got it. I thought you received it after the reboot AND once you sent
the firsts packets, since you said that some pings worked. But now
that this point is clear, I think we can move forward :). Thank you
very much!
>
> For example during reboot we do re-setup the virt queues:
>
> #1 0x00000000010f3e7a in vhost_kernel_set_vring_base (dev=0x21f5f30, ring=0x3ff84d74e88) at /home/cborntra/REPOS/qemu/hw/virtio/vhost-backend.c:126
> #2 0x00000000010f2f92 in vhost_virtqueue_start (idx=0, vq=0x21f6180, vdev=0x241d570, dev=0x21f5f30) at /home/cborntra/REPOS/qemu/hw/virtio/vhost.c:1016
> #3 vhost_dev_start (hdev=hdev@entry=0x21f5f30, vdev=vdev@entry=0x241d570) at /home/cborntra/REPOS/qemu/hw/virtio/vhost.c:1646
> #4 0x00000000011c265a in vhost_net_start_one (dev=0x241d570, net=0x21f5f30) at /home/cborntra/REPOS/qemu/hw/net/vhost_net.c:236
> #5 vhost_net_start (dev=dev@entry=0x241d570, ncs=0x2450f40, total_queues=total_queues@entry=1) at /home/cborntra/REPOS/qemu/hw/net/vhost_net.c:338
> #6 0x00000000010cfdfe in virtio_net_vhost_status (status=15 '\017', n=0x241d570) at /home/cborntra/REPOS/qemu/hw/net/virtio-net.c:250
> #7 virtio_net_set_status (vdev=0x241d570, status=<optimized out>) at /home/cborntra/REPOS/qemu/hw/net/virtio-net.c:331
> #8 0x00000000010eaef4 in virtio_set_status (vdev=vdev@entry=0x241d570, val=<optimized out>) at /home/cborntra/REPOS/qemu/hw/virtio/virtio.c:1956
> #9 0x000000000110ba78 in virtio_ccw_cb (sch=0x2422c30, ccw=...) at /home/cborntra/REPOS/qemu/hw/s390x/virtio-ccw.c:509
> #10 0x00000000011053fc in css_interpret_ccw (sch=sch@entry=0x2422c30, ccw_addr=<optimized out>, suspend_allowed=suspend_allowed@entry=false) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1108
> #11 0x000000000110557c in sch_handle_start_func_virtual (sch=0x2422c30) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1162
> #12 do_subchannel_work_virtual (sch=0x2422c30) at /home/cborntra/REPOS/qemu/hw/s390x/css.c:1256
> #13 0x0000000001168592 in ioinst_handle_ssch (cpu=cpu@entry=0x234b920, reg1=<optimized out>, ipb=<optimized out>, ra=ra@entry=0) at /home/cborntra/REPOS/qemu/target/s390x/ioinst.c:218
> #14 0x0000000001170012 in handle_b2 (ipa1=<optimized out>, run=0x3ff97880000, cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1279
> #15 handle_instruction (run=0x3ff97880000, cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1664
> #16 handle_intercept (cpu=0x234b920) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1747
> #17 kvm_arch_handle_exit (cs=cs@entry=0x234b920, run=run@entry=0x3ff97880000) at /home/cborntra/REPOS/qemu/target/s390x/kvm.c:1937
> #18 0x00000000010972dc in kvm_cpu_exec (cpu=cpu@entry=0x234b920) at /home/cborntra/REPOS/qemu/accel/kvm/kvm-all.c:2445
> #19 0x00000000010784f6 in qemu_kvm_cpu_thread_fn (arg=0x234b920) at /home/cborntra/REPOS/qemu/cpus.c:1246
> #20 qemu_kvm_cpu_thread_fn (arg=arg@entry=0x234b920) at /home/cborntra/REPOS/qemu/cpus.c:1218
> #21 0x00000000013891fa in qemu_thread_start (args=0x2372f30) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:519
> #22 0x000003ff93809ed6 in start_thread () from target:/lib64/libpthread.so.0
> #23 0x000003ff93705e46 in thread_start () from target:/lib64/libc.so.6
>
^ permalink raw reply [flat|nested] 15+ messages in thread