diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-12 00:08:16 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-12 00:08:16 (GMT) |
commit | 3c81bdd9e7ec5c7e28bedf7c7bd3b8911ffee94a (patch) | |
tree | 84c162f7a2024fb7e74c3fc795d6dcffb4ae6b65 | |
parent | 7ec6131b55184084d091953fad9e5c785c5b500b (diff) | |
parent | 47283bef7ed356629467d1fac61687756e48f254 (diff) | |
download | linux-3c81bdd9e7ec5c7e28bedf7c7bd3b8911ffee94a.tar.xz |
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull vhost infrastructure updates from Michael S. Tsirkin:
"This reworks vhost core dropping unnecessary RCU uses in favor of VQ
mutexes which are used on fast path anyway. This fixes worst-case
latency for users which change the memory mappings a lot. Memory
allocation for vhost-net now supports fallback on vmalloc (same as for
vhost-scsi) this makes it possible to create the device on systems
where memory is very fragmented, with slightly lower performance"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: move memory pointer to VQs
vhost: move acked_features to VQs
vhost: replace rcu with mutex
vhost-net: extend device allocation to vmalloc
-rw-r--r-- | drivers/vhost/net.c | 35 | ||||
-rw-r--r-- | drivers/vhost/scsi.c | 26 | ||||
-rw-r--r-- | drivers/vhost/test.c | 11 | ||||
-rw-r--r-- | drivers/vhost/vhost.c | 97 | ||||
-rw-r--r-- | drivers/vhost/vhost.h | 19 |
5 files changed, 101 insertions, 87 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index be414d2..971a760 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -17,6 +17,7 @@ #include <linux/workqueue.h> #include <linux/file.h> #include <linux/slab.h> +#include <linux/vmalloc.h> #include <linux/net.h> #include <linux/if_packet.h> @@ -373,7 +374,7 @@ static void handle_tx(struct vhost_net *net) % UIO_MAXIOV == nvq->done_idx)) break; - head = vhost_get_vq_desc(&net->dev, vq, vq->iov, + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), &out, &in, NULL, NULL); @@ -505,7 +506,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, r = -ENOBUFS; goto err; } - r = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, + r = vhost_get_vq_desc(vq, vq->iov + seg, ARRAY_SIZE(vq->iov) - seg, &out, &in, log, log_num); if (unlikely(r < 0)) @@ -584,9 +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; @@ -699,18 +700,30 @@ static void handle_rx_net(struct vhost_work *work) handle_rx(net); } +static void vhost_net_free(void *addr) +{ + if (is_vmalloc_addr(addr)) + vfree(addr); + else + kfree(addr); +} + static int vhost_net_open(struct inode *inode, struct file *f) { - struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); + struct vhost_net *n; struct vhost_dev *dev; struct vhost_virtqueue **vqs; int i; - if (!n) - return -ENOMEM; + n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); + if (!n) { + n = vmalloc(sizeof *n); + if (!n) + return -ENOMEM; + } vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL); if (!vqs) { - kfree(n); + vhost_net_free(n); return -ENOMEM; } @@ -827,7 +840,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) * since jobs can re-queue themselves. */ vhost_net_flush(n); kfree(n->dev.vqs); - kfree(n); + vhost_net_free(n); return 0; } @@ -1038,15 +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].vq.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 aeb5131..e9c280f 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -606,7 +606,7 @@ tcm_vhost_do_evt_work(struct vhost_scsi *vs, struct tcm_vhost_evt *evt) again: vhost_disable_notify(&vs->dev, vq); - head = vhost_get_vq_desc(&vs->dev, vq, vq->iov, + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), &out, &in, NULL, NULL); if (head < 0) { @@ -945,7 +945,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) vhost_disable_notify(&vs->dev, vq); for (;;) { - head = vhost_get_vq_desc(&vs->dev, vq, vq->iov, + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), &out, &in, NULL, NULL); pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n", @@ -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..d9c501e 100644 --- a/drivers/vhost/test.c +++ b/drivers/vhost/test.c @@ -53,7 +53,7 @@ static void handle_vq(struct vhost_test *n) vhost_disable_notify(&n->dev, vq); for (;;) { - head = vhost_get_vq_desc(&n->dev, vq, vq->iov, + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), &out, &in, NULL, NULL); @@ -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 78987e4..c90f437 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -18,7 +18,6 @@ #include <linux/mmu_context.h> #include <linux/miscdevice.h> #include <linux/mutex.h> -#include <linux/rcupdate.h> #include <linux/poll.h> #include <linux/file.h> #include <linux/highmem.h> @@ -191,6 +190,7 @@ static void vhost_vq_reset(struct vhost_dev *dev, vq->log_used = false; vq->log_addr = -1ull; vq->private_data = NULL; + vq->acked_features = 0; vq->log_base = NULL; vq->error_ctx = NULL; vq->error = NULL; @@ -198,6 +198,7 @@ static void vhost_vq_reset(struct vhost_dev *dev, vq->call_ctx = NULL; vq->call = NULL; vq->log_ctx = NULL; + vq->memory = NULL; } static int vhost_worker(void *data) @@ -415,11 +416,18 @@ EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); /* Caller should have device mutex */ void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory) { + int i; + vhost_dev_cleanup(dev, true); /* Restore memory to default empty mapping. */ memory->nregions = 0; - RCU_INIT_POINTER(dev->memory, memory); + dev->memory = memory; + /* We don't need VQ locks below since vhost_dev_cleanup makes sure + * VQs aren't running. + */ + for (i = 0; i < dev->nvqs; ++i) + dev->vqs[i]->memory = memory; } EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); @@ -462,10 +470,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked) fput(dev->log_file); dev->log_file = NULL; /* No one will access memory at this point */ - kfree(rcu_dereference_protected(dev->memory, - locked == - lockdep_is_held(&dev->mutex))); - RCU_INIT_POINTER(dev->memory, NULL); + kfree(dev->memory); + dev->memory = NULL; WARN_ON(!list_empty(&dev->work_list)); if (dev->worker) { kthread_stop(dev->worker); @@ -524,11 +530,13 @@ 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 +546,12 @@ 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) && @@ -555,26 +563,19 @@ static int vq_access_ok(struct vhost_dev *d, unsigned int num, /* Caller should have device mutex but not vq mutex */ int vhost_log_access_ok(struct vhost_dev *dev) { - struct vhost_memory *mp; - - mp = rcu_dereference_protected(dev->memory, - lockdep_is_held(&dev->mutex)); - return memory_access_ok(dev, mp, 1); + return memory_access_ok(dev, dev->memory, 1); } 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)) && + return vq_memory_access_ok(log_base, vq->memory, + 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 +585,8 @@ 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); @@ -593,6 +594,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) { struct vhost_memory mem, *newmem, *oldmem; unsigned long size = offsetof(struct vhost_memory, regions); + int i; if (copy_from_user(&mem, m, size)) return -EFAULT; @@ -611,15 +613,19 @@ 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; } - oldmem = rcu_dereference_protected(d->memory, - lockdep_is_held(&d->mutex)); - rcu_assign_pointer(d->memory, newmem); - synchronize_rcu(); + oldmem = d->memory; + d->memory = newmem; + + /* All memory accesses are done under some VQ mutex. */ + for (i = 0; i < d->nvqs; ++i) { + mutex_lock(&d->vqs[i]->mutex); + d->vqs[i]->memory = newmem; + mutex_unlock(&d->vqs[i]->mutex); + } kfree(oldmem); return 0; } @@ -718,7 +724,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) * If it is not, we don't as size might not have been setup. * We will verify when backend is configured. */ if (vq->private_data) { - if (!vq_access_ok(d, vq->num, + if (!vq_access_ok(vq, vq->num, (void __user *)(unsigned long)a.desc_user_addr, (void __user *)(unsigned long)a.avail_user_addr, (void __user *)(unsigned long)a.used_user_addr)) { @@ -858,7 +864,7 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) vq = d->vqs[i]; mutex_lock(&vq->mutex); /* If ring is inactive, will check when it's enabled. */ - if (vq->private_data && !vq_log_access_ok(d, vq, base)) + if (vq->private_data && !vq_log_access_ok(vq, base)) r = -EFAULT; else vq->log_base = base; @@ -1044,7 +1050,7 @@ int vhost_init_used(struct vhost_virtqueue *vq) } EXPORT_SYMBOL_GPL(vhost_init_used); -static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, +static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, struct iovec iov[], int iov_size) { const struct vhost_memory_region *reg; @@ -1053,9 +1059,7 @@ static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, u64 s = 0; int ret = 0; - rcu_read_lock(); - - mem = rcu_dereference(dev->memory); + mem = vq->memory; while ((u64)len > s) { u64 size; if (unlikely(ret >= iov_size)) { @@ -1077,7 +1081,6 @@ static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len, ++ret; } - rcu_read_unlock(); return ret; } @@ -1102,7 +1105,7 @@ static unsigned next_desc(struct vring_desc *desc) return next; } -static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, +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, @@ -1121,7 +1124,7 @@ static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, return -EINVAL; } - ret = translate_desc(dev, indirect->addr, indirect->len, vq->indirect, + ret = translate_desc(vq, indirect->addr, indirect->len, vq->indirect, UIO_MAXIOV); if (unlikely(ret < 0)) { vq_err(vq, "Translation failure %d in indirect.\n", ret); @@ -1161,7 +1164,7 @@ static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, return -EINVAL; } - ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, + ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count, iov_size - iov_count); if (unlikely(ret < 0)) { vq_err(vq, "Translation failure %d indirect idx %d\n", @@ -1198,7 +1201,7 @@ static int get_indirect(struct vhost_dev *dev, 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(struct vhost_dev *dev, 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) @@ -1272,7 +1275,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, return -EFAULT; } if (desc.flags & VRING_DESC_F_INDIRECT) { - ret = get_indirect(dev, vq, iov, iov_size, + ret = get_indirect(vq, iov, iov_size, out_num, in_num, log, log_num, &desc); if (unlikely(ret < 0)) { @@ -1283,7 +1286,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, continue; } - ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count, + ret = translate_desc(vq, desc.addr, desc.len, iov + iov_count, iov_size - iov_count); if (unlikely(ret < 0)) { vq_err(vq, "Translation failure %d descriptor idx %d\n", @@ -1426,11 +1429,11 @@ 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"); @@ -1491,7 +1494,7 @@ 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", @@ -1528,7 +1531,7 @@ 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", diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 35eeb2a..3eda654 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -104,20 +104,18 @@ struct vhost_virtqueue { struct iovec *indirect; struct vring_used_elem *heads; /* Protected by virtqueue mutex. */ + struct vhost_memory *memory; void *private_data; + unsigned acked_features; /* Log write descriptors */ void __user *log_base; struct vhost_log *log; }; struct vhost_dev { - /* Readers use RCU to access memory table pointer - * log base pointer and features. - * Writers use mutex below.*/ - struct vhost_memory __rcu *memory; + struct vhost_memory *memory; struct mm_struct *mm; struct mutex mutex; - unsigned acked_features; struct vhost_virtqueue **vqs; int nvqs; struct file *log_file; @@ -140,7 +138,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); int vhost_vq_access_ok(struct vhost_virtqueue *vq); int vhost_log_access_ok(struct vhost_dev *); -int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, +int vhost_get_vq_desc(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); @@ -174,13 +172,8 @@ 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 |