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Message-ID: <1401962195-15066-1-git-send-email-mst@redhat.com>
Date: Thu, 5 Jun 2014 13:44:14 +0300
From: "Michael S. Tsirkin" <mst@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: pbonzini@...hat.com, Eric Dumazet <eric.dumazet@...il.com>,
kvm@...r.kernel.org, virtualization@...ts.linux-foundation.org,
netdev@...r.kernel.org
Subject: [PATCH 1/2] vhost: move acked_features to VQs
Refactor code to make sure features are only accessed
under VQ mutex. This makes everything simpler, no need
for RCU here anymore.
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
---
This is on top of the recent pull request that I sent.
drivers/vhost/vhost.h | 11 +++--------
drivers/vhost/net.c | 8 +++-----
drivers/vhost/scsi.c | 22 +++++++++++++---------
drivers/vhost/test.c | 9 ++++++---
drivers/vhost/vhost.c | 31 ++++++++++++++++---------------
5 files changed, 41 insertions(+), 40 deletions(-)
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 35eeb2a..ff454a0 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -105,6 +105,7 @@ struct vhost_virtqueue {
struct vring_used_elem *heads;
/* Protected by virtqueue mutex. */
void *private_data;
+ unsigned acked_features;
/* Log write descriptors */
void __user *log_base;
struct vhost_log *log;
@@ -117,7 +118,6 @@ struct vhost_dev {
struct vhost_memory __rcu *memory;
struct mm_struct *mm;
struct mutex mutex;
- unsigned acked_features;
struct vhost_virtqueue **vqs;
int nvqs;
struct file *log_file;
@@ -174,13 +174,8 @@ enum {
(1ULL << VHOST_F_LOG_ALL),
};
-static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
+static inline int vhost_has_feature(struct vhost_virtqueue *vq, int bit)
{
- unsigned acked_features;
-
- /* TODO: check that we are running from vhost_worker or dev mutex is
- * held? */
- acked_features = rcu_dereference_index_check(dev->acked_features, 1);
- return acked_features & (1 << bit);
+ return vq->acked_features & (1 << bit);
}
#endif
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index e489161..7635b59 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -585,9 +585,9 @@ static void handle_rx(struct vhost_net *net)
vhost_hlen = nvq->vhost_hlen;
sock_hlen = nvq->sock_hlen;
- vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
+ vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
- mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
+ mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF);
while ((sock_len = peek_head_len(sock->sk))) {
sock_len += sock_hlen;
@@ -1051,15 +1051,13 @@ static int vhost_net_set_features(struct vhost_net *n, u64 features)
mutex_unlock(&n->dev.mutex);
return -EFAULT;
}
- n->dev.acked_features = features;
- smp_wmb();
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
mutex_lock(&n->vqs[i].vq.mutex);
+ n->vqs[i].acked_features = features;
n->vqs[i].vhost_hlen = vhost_hlen;
n->vqs[i].sock_hlen = sock_hlen;
mutex_unlock(&n->vqs[i].vq.mutex);
}
- vhost_net_flush(n);
mutex_unlock(&n->dev.mutex);
return 0;
}
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index cf50ce9..f1f284f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1373,6 +1373,9 @@ err_dev:
static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
{
+ struct vhost_virtqueue *vq;
+ int i;
+
if (features & ~VHOST_SCSI_FEATURES)
return -EOPNOTSUPP;
@@ -1382,9 +1385,13 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
mutex_unlock(&vs->dev.mutex);
return -EFAULT;
}
- vs->dev.acked_features = features;
- smp_wmb();
- vhost_scsi_flush(vs);
+
+ for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
+ vq = &vs->vqs[i].vq;
+ mutex_lock(&vq->mutex);
+ vq->acked_features = features;
+ mutex_unlock(&vq->mutex);
+ }
mutex_unlock(&vs->dev.mutex);
return 0;
}
@@ -1591,10 +1598,6 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
return;
mutex_lock(&vs->dev.mutex);
- if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {
- mutex_unlock(&vs->dev.mutex);
- return;
- }
if (plug)
reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
@@ -1603,8 +1606,9 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
mutex_lock(&vq->mutex);
- tcm_vhost_send_evt(vs, tpg, lun,
- VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
+ if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
+ tcm_vhost_send_evt(vs, tpg, lun,
+ VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
mutex_unlock(&vq->mutex);
mutex_unlock(&vs->dev.mutex);
}
diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index c2a54fb..6fa3bf8 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -241,15 +241,18 @@ done:
static int vhost_test_set_features(struct vhost_test *n, u64 features)
{
+ struct vhost_virtqueue *vq;
+
mutex_lock(&n->dev.mutex);
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&n->dev)) {
mutex_unlock(&n->dev.mutex);
return -EFAULT;
}
- n->dev.acked_features = features;
- smp_wmb();
- vhost_test_flush(n);
+ vq = &n->vqs[VHOST_TEST_VQ];
+ mutex_lock(&vq->mutex);
+ vq->acked_features = features;
+ mutex_unlock(&vq->mutex);
mutex_unlock(&n->dev.mutex);
return 0;
}
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 1c05e60..9183f0b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -524,11 +524,13 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem,
for (i = 0; i < d->nvqs; ++i) {
int ok;
+ bool log;
+
mutex_lock(&d->vqs[i]->mutex);
+ log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL);
/* If ring is inactive, will check when it's enabled. */
if (d->vqs[i]->private_data)
- ok = vq_memory_access_ok(d->vqs[i]->log_base, mem,
- log_all);
+ ok = vq_memory_access_ok(d->vqs[i]->log_base, mem, log);
else
ok = 1;
mutex_unlock(&d->vqs[i]->mutex);
@@ -538,12 +540,12 @@ static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem,
return 1;
}
-static int vq_access_ok(struct vhost_dev *d, unsigned int num,
+static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num,
struct vring_desc __user *desc,
struct vring_avail __user *avail,
struct vring_used __user *used)
{
- size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+ size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
return access_ok(VERIFY_READ, desc, num * sizeof *desc) &&
access_ok(VERIFY_READ, avail,
sizeof *avail + num * sizeof *avail->ring + s) &&
@@ -565,16 +567,16 @@ EXPORT_SYMBOL_GPL(vhost_log_access_ok);
/* Verify access for write logging. */
/* Caller should have vq mutex and device mutex */
-static int vq_log_access_ok(struct vhost_dev *d, struct vhost_virtqueue *vq,
+static int vq_log_access_ok(struct vhost_virtqueue *vq,
void __user *log_base)
{
struct vhost_memory *mp;
- size_t s = vhost_has_feature(d, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+ size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
mp = rcu_dereference_protected(vq->dev->memory,
lockdep_is_held(&vq->mutex));
return vq_memory_access_ok(log_base, mp,
- vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) &&
+ vhost_has_feature(vq, VHOST_F_LOG_ALL)) &&
(!vq->log_used || log_access_ok(log_base, vq->log_addr,
sizeof *vq->used +
vq->num * sizeof *vq->used->ring + s));
@@ -584,8 +586,8 @@ static int vq_log_access_ok(struct vhost_dev *d, struct vhost_virtqueue *vq,
/* Caller should have vq mutex and device mutex */
int vhost_vq_access_ok(struct vhost_virtqueue *vq)
{
- return vq_access_ok(vq->dev, vq->num, vq->desc, vq->avail, vq->used) &&
- vq_log_access_ok(vq->dev, vq, vq->log_base);
+ return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) &&
+ vq_log_access_ok(vq, vq->log_base);
}
EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
@@ -612,8 +614,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
return -EFAULT;
}
- if (!memory_access_ok(d, newmem,
- vhost_has_feature(d, VHOST_F_LOG_ALL))) {
+ if (!memory_access_ok(d, newmem, 0)) {
kfree(newmem);
return -EFAULT;
}
@@ -1434,11 +1435,11 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
* interrupts. */
smp_mb();
- if (vhost_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
+ if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) &&
unlikely(vq->avail_idx == vq->last_avail_idx))
return true;
- if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
+ if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
__u16 flags;
if (__get_user(flags, &vq->avail->flags)) {
vq_err(vq, "Failed to get flags");
@@ -1499,7 +1500,7 @@ bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
return false;
vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;
- if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
+ if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
r = vhost_update_used_flags(vq);
if (r) {
vq_err(vq, "Failed to enable notification at %p: %d\n",
@@ -1536,7 +1537,7 @@ void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
if (vq->used_flags & VRING_USED_F_NO_NOTIFY)
return;
vq->used_flags |= VRING_USED_F_NO_NOTIFY;
- if (!vhost_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
+ if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) {
r = vhost_update_used_flags(vq);
if (r)
vq_err(vq, "Failed to enable notification at %p: %d\n",
--
MST
--
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