[v3,3/3] vhost: optimize vhost virtqueue struct
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Commit Message
This patch moves vhost_virtqueue struct fields in order
to both optimize packing and move hot fields on the first
cachelines.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/librte_vhost/vhost.c | 6 ++--
lib/librte_vhost/vhost.h | 54 ++++++++++++++++++-----------------
lib/librte_vhost/vhost_user.c | 19 ++++++------
lib/librte_vhost/virtio_net.c | 12 ++++----
4 files changed, 46 insertions(+), 45 deletions(-)
Comments
Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Thursday, March 18, 2021 1:09 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com;
> david.marchand@redhat.com; olivier.matz@6wind.com; bnemeth@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v3 3/3] vhost: optimize vhost virtqueue struct
>
> This patch moves vhost_virtqueue struct fields in order
> to both optimize packing and move hot fields on the first
> cachelines.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/librte_vhost/vhost.c | 6 ++--
> lib/librte_vhost/vhost.h | 54 ++++++++++++++++++-----------------
> lib/librte_vhost/vhost_user.c | 19 ++++++------
> lib/librte_vhost/virtio_net.c | 12 ++++----
> 4 files changed, 46 insertions(+), 45 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index a8032e3ba1..04d63b2f02 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -524,7 +524,7 @@ vring_translate(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
> if (log_translate(dev, vq) < 0)
> return -1;
>
> - vq->access_ok = 1;
> + vq->access_ok = true;
>
> return 0;
> }
> @@ -535,7 +535,7 @@ vring_invalidate(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> vhost_user_iotlb_wr_lock(vq);
>
> - vq->access_ok = 0;
> + vq->access_ok = false;
> vq->desc = NULL;
> vq->avail = NULL;
> vq->used = NULL;
> @@ -1451,7 +1451,7 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
>
> rte_spinlock_lock(&vq->access_lock);
>
> - if (unlikely(vq->enabled == 0 || vq->avail == NULL))
> + if (unlikely(!vq->enabled || vq->avail == NULL))
> goto out;
>
> ret = *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 3a71dfeed9..f628714c24 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -133,7 +133,7 @@ struct vhost_virtqueue {
> struct vring_used *used;
> struct vring_packed_desc_event *device_event;
> };
> - uint32_t size;
> + uint16_t size;
>
> uint16_t last_avail_idx;
> uint16_t last_used_idx;
> @@ -143,29 +143,12 @@ struct vhost_virtqueue {
> #define VIRTIO_INVALID_EVENTFD (-1)
> #define VIRTIO_UNINITIALIZED_EVENTFD (-2)
>
> - int enabled;
> - int access_ok;
> - int ready;
> - int notif_enable;
> -#define VIRTIO_UNINITIALIZED_NOTIF (-1)
> + bool enabled;
> + bool access_ok;
> + bool ready;
In vhost_user_set_vring_call and vhost_user_set_vring_kick, 'vq->ready = 0' should
also be changed to 'vq->ready = false' 😊.
Thanks,
Chenbo
>
> rte_spinlock_t access_lock;
>
> - /* Used to notify the guest (trigger interrupt) */
> - int callfd;
> - /* Currently unused as polling mode is enabled */
> - int kickfd;
> -
> - /* Physical address of used ring, for logging */
> - uint64_t log_guest_addr;
> -
> - /* inflight share memory info */
> - union {
> - struct rte_vhost_inflight_info_split *inflight_split;
> - struct rte_vhost_inflight_info_packed *inflight_packed;
> - };
> - struct rte_vhost_resubmit_info *resubmit_inflight;
> - uint64_t global_counter;
>
> union {
> struct vring_used_elem *shadow_used_split;
> @@ -176,22 +159,36 @@ struct vhost_virtqueue {
> uint16_t shadow_aligned_idx;
> /* Record packed ring first dequeue desc index */
> uint16_t shadow_last_used_idx;
> - struct vhost_vring_addr ring_addrs;
>
> - struct batch_copy_elem *batch_copy_elems;
> uint16_t batch_copy_nb_elems;
> + struct batch_copy_elem *batch_copy_elems;
> bool used_wrap_counter;
> bool avail_wrap_counter;
>
> - struct log_cache_entry *log_cache;
> - uint16_t log_cache_nb_elem;
> + /* Physical address of used ring, for logging */
> + uint16_t log_cache_nb_elem;
> + uint64_t log_guest_addr;
> + struct log_cache_entry *log_cache;
>
> rte_rwlock_t iotlb_lock;
> rte_rwlock_t iotlb_pending_lock;
> struct rte_mempool *iotlb_pool;
> TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
> - int iotlb_cache_nr;
> TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
> + int iotlb_cache_nr;
> +
> + /* Used to notify the guest (trigger interrupt) */
> + int callfd;
> + /* Currently unused as polling mode is enabled */
> + int kickfd;
> +
> + /* inflight share memory info */
> + union {
> + struct rte_vhost_inflight_info_split *inflight_split;
> + struct rte_vhost_inflight_info_packed *inflight_packed;
> + };
> + struct rte_vhost_resubmit_info *resubmit_inflight;
> + uint64_t global_counter;
>
> /* operation callbacks for async dma */
> struct rte_vhost_async_channel_ops async_ops;
> @@ -212,6 +209,11 @@ struct vhost_virtqueue {
> bool async_inorder;
> bool async_registered;
> uint16_t async_threshold;
> +
> + int notif_enable;
> +#define VIRTIO_UNINITIALIZED_NOTIF (-1)
> +
> + struct vhost_vring_addr ring_addrs;
> } __rte_cache_aligned;
>
> /* Virtio device status as per Virtio specification */
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 4d9e76e49e..ce31dd76d4 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -406,6 +406,11 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
> if (validate_msg_fds(msg, 0) != 0)
> return RTE_VHOST_MSG_RESULT_ERR;
>
> + if (msg->payload.state.num > 32768) {
> + VHOST_LOG_CONFIG(ERR, "invalid virtqueue size %u\n", msg-
> >payload.state.num);
> + return RTE_VHOST_MSG_RESULT_ERR;
> + }
> +
> vq->size = msg->payload.state.num;
>
> /* VIRTIO 1.0, 2.4 Virtqueues says:
> @@ -425,12 +430,6 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
> }
> }
>
> - if (vq->size > 32768) {
> - VHOST_LOG_CONFIG(ERR,
> - "invalid virtqueue size %u\n", vq->size);
> - return RTE_VHOST_MSG_RESULT_ERR;
> - }
> -
> if (vq_is_packed(dev)) {
> if (vq->shadow_used_packed)
> rte_free(vq->shadow_used_packed);
> @@ -713,7 +712,7 @@ translate_ring_addresses(struct virtio_net *dev, int
> vq_index)
> return dev;
> }
>
> - vq->access_ok = 1;
> + vq->access_ok = true;
> return dev;
> }
>
> @@ -771,7 +770,7 @@ translate_ring_addresses(struct virtio_net *dev, int
> vq_index)
> vq->last_avail_idx = vq->used->idx;
> }
>
> - vq->access_ok = 1;
> + vq->access_ok = true;
>
> VHOST_LOG_CONFIG(DEBUG, "(%d) mapped address desc: %p\n",
> dev->vid, vq->desc);
> @@ -1918,7 +1917,7 @@ vhost_user_set_vring_kick(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> * the SET_VRING_ENABLE message.
> */
> if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
> - vq->enabled = 1;
> + vq->enabled = true;
> if (dev->notify_ops->vring_state_changed)
> dev->notify_ops->vring_state_changed(
> dev->vid, file.index, 1);
> @@ -2043,7 +2042,7 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
> int main_fd __rte_unused)
> {
> struct virtio_net *dev = *pdev;
> - int enable = (int)msg->payload.state.num;
> + bool enable = !!msg->payload.state.num;
> int index = (int)msg->payload.state.index;
>
> if (validate_msg_fds(msg, 0) != 0)
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 583bf379c6..3d8e29df09 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1396,13 +1396,13 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t
> queue_id,
>
> rte_spinlock_lock(&vq->access_lock);
>
> - if (unlikely(vq->enabled == 0))
> + if (unlikely(!vq->enabled))
> goto out_access_unlock;
>
> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> vhost_user_iotlb_rd_lock(vq);
>
> - if (unlikely(vq->access_ok == 0))
> + if (unlikely(!vq->access_ok))
> if (unlikely(vring_translate(dev, vq) < 0))
> goto out;
>
> @@ -1753,13 +1753,13 @@ virtio_dev_rx_async_submit(struct virtio_net *dev,
> uint16_t queue_id,
>
> rte_spinlock_lock(&vq->access_lock);
>
> - if (unlikely(vq->enabled == 0 || !vq->async_registered))
> + if (unlikely(!vq->enabled || !vq->async_registered))
> goto out_access_unlock;
>
> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> vhost_user_iotlb_rd_lock(vq);
>
> - if (unlikely(vq->access_ok == 0))
> + if (unlikely(!vq->access_ok))
> if (unlikely(vring_translate(dev, vq) < 0))
> goto out;
>
> @@ -2518,7 +2518,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
> if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
> return 0;
>
> - if (unlikely(vq->enabled == 0)) {
> + if (unlikely(!vq->enabled)) {
> count = 0;
> goto out_access_unlock;
> }
> @@ -2526,7 +2526,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> vhost_user_iotlb_rd_lock(vq);
>
> - if (unlikely(vq->access_ok == 0))
> + if (unlikely(!vq->access_ok))
> if (unlikely(vring_translate(dev, vq) < 0)) {
> count = 0;
> goto out;
> --
> 2.30.2
On 3/18/21 4:23 AM, Xia, Chenbo wrote:
> Hi Maxime,
>
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Sent: Thursday, March 18, 2021 1:09 AM
>> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com;
>> david.marchand@redhat.com; olivier.matz@6wind.com; bnemeth@redhat.com
>> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Subject: [PATCH v3 3/3] vhost: optimize vhost virtqueue struct
>>
>> This patch moves vhost_virtqueue struct fields in order
>> to both optimize packing and move hot fields on the first
>> cachelines.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>> lib/librte_vhost/vhost.c | 6 ++--
>> lib/librte_vhost/vhost.h | 54 ++++++++++++++++++-----------------
>> lib/librte_vhost/vhost_user.c | 19 ++++++------
>> lib/librte_vhost/virtio_net.c | 12 ++++----
>> 4 files changed, 46 insertions(+), 45 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
>> index a8032e3ba1..04d63b2f02 100644
>> --- a/lib/librte_vhost/vhost.c
>> +++ b/lib/librte_vhost/vhost.c
>> @@ -524,7 +524,7 @@ vring_translate(struct virtio_net *dev, struct
>> vhost_virtqueue *vq)
>> if (log_translate(dev, vq) < 0)
>> return -1;
>>
>> - vq->access_ok = 1;
>> + vq->access_ok = true;
>>
>> return 0;
>> }
>> @@ -535,7 +535,7 @@ vring_invalidate(struct virtio_net *dev, struct
>> vhost_virtqueue *vq)
>> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
>> vhost_user_iotlb_wr_lock(vq);
>>
>> - vq->access_ok = 0;
>> + vq->access_ok = false;
>> vq->desc = NULL;
>> vq->avail = NULL;
>> vq->used = NULL;
>> @@ -1451,7 +1451,7 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
>>
>> rte_spinlock_lock(&vq->access_lock);
>>
>> - if (unlikely(vq->enabled == 0 || vq->avail == NULL))
>> + if (unlikely(!vq->enabled || vq->avail == NULL))
>> goto out;
>>
>> ret = *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
>> index 3a71dfeed9..f628714c24 100644
>> --- a/lib/librte_vhost/vhost.h
>> +++ b/lib/librte_vhost/vhost.h
>> @@ -133,7 +133,7 @@ struct vhost_virtqueue {
>> struct vring_used *used;
>> struct vring_packed_desc_event *device_event;
>> };
>> - uint32_t size;
>> + uint16_t size;
>>
>> uint16_t last_avail_idx;
>> uint16_t last_used_idx;
>> @@ -143,29 +143,12 @@ struct vhost_virtqueue {
>> #define VIRTIO_INVALID_EVENTFD (-1)
>> #define VIRTIO_UNINITIALIZED_EVENTFD (-2)
>>
>> - int enabled;
>> - int access_ok;
>> - int ready;
>> - int notif_enable;
>> -#define VIRTIO_UNINITIALIZED_NOTIF (-1)
>> + bool enabled;
>> + bool access_ok;
>> + bool ready;
> In vhost_user_set_vring_call and vhost_user_set_vring_kick, 'vq->ready = 0' should
> also be changed to 'vq->ready = false' 😊.
Thanks Chenbo, I indeed missed these. V4 is on its way.
Maxime
> Thanks,
> Chenbo
>
@@ -524,7 +524,7 @@ vring_translate(struct virtio_net *dev, struct vhost_virtqueue *vq)
if (log_translate(dev, vq) < 0)
return -1;
- vq->access_ok = 1;
+ vq->access_ok = true;
return 0;
}
@@ -535,7 +535,7 @@ vring_invalidate(struct virtio_net *dev, struct vhost_virtqueue *vq)
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
vhost_user_iotlb_wr_lock(vq);
- vq->access_ok = 0;
+ vq->access_ok = false;
vq->desc = NULL;
vq->avail = NULL;
vq->used = NULL;
@@ -1451,7 +1451,7 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
rte_spinlock_lock(&vq->access_lock);
- if (unlikely(vq->enabled == 0 || vq->avail == NULL))
+ if (unlikely(!vq->enabled || vq->avail == NULL))
goto out;
ret = *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
@@ -133,7 +133,7 @@ struct vhost_virtqueue {
struct vring_used *used;
struct vring_packed_desc_event *device_event;
};
- uint32_t size;
+ uint16_t size;
uint16_t last_avail_idx;
uint16_t last_used_idx;
@@ -143,29 +143,12 @@ struct vhost_virtqueue {
#define VIRTIO_INVALID_EVENTFD (-1)
#define VIRTIO_UNINITIALIZED_EVENTFD (-2)
- int enabled;
- int access_ok;
- int ready;
- int notif_enable;
-#define VIRTIO_UNINITIALIZED_NOTIF (-1)
+ bool enabled;
+ bool access_ok;
+ bool ready;
rte_spinlock_t access_lock;
- /* Used to notify the guest (trigger interrupt) */
- int callfd;
- /* Currently unused as polling mode is enabled */
- int kickfd;
-
- /* Physical address of used ring, for logging */
- uint64_t log_guest_addr;
-
- /* inflight share memory info */
- union {
- struct rte_vhost_inflight_info_split *inflight_split;
- struct rte_vhost_inflight_info_packed *inflight_packed;
- };
- struct rte_vhost_resubmit_info *resubmit_inflight;
- uint64_t global_counter;
union {
struct vring_used_elem *shadow_used_split;
@@ -176,22 +159,36 @@ struct vhost_virtqueue {
uint16_t shadow_aligned_idx;
/* Record packed ring first dequeue desc index */
uint16_t shadow_last_used_idx;
- struct vhost_vring_addr ring_addrs;
- struct batch_copy_elem *batch_copy_elems;
uint16_t batch_copy_nb_elems;
+ struct batch_copy_elem *batch_copy_elems;
bool used_wrap_counter;
bool avail_wrap_counter;
- struct log_cache_entry *log_cache;
- uint16_t log_cache_nb_elem;
+ /* Physical address of used ring, for logging */
+ uint16_t log_cache_nb_elem;
+ uint64_t log_guest_addr;
+ struct log_cache_entry *log_cache;
rte_rwlock_t iotlb_lock;
rte_rwlock_t iotlb_pending_lock;
struct rte_mempool *iotlb_pool;
TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
- int iotlb_cache_nr;
TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
+ int iotlb_cache_nr;
+
+ /* Used to notify the guest (trigger interrupt) */
+ int callfd;
+ /* Currently unused as polling mode is enabled */
+ int kickfd;
+
+ /* inflight share memory info */
+ union {
+ struct rte_vhost_inflight_info_split *inflight_split;
+ struct rte_vhost_inflight_info_packed *inflight_packed;
+ };
+ struct rte_vhost_resubmit_info *resubmit_inflight;
+ uint64_t global_counter;
/* operation callbacks for async dma */
struct rte_vhost_async_channel_ops async_ops;
@@ -212,6 +209,11 @@ struct vhost_virtqueue {
bool async_inorder;
bool async_registered;
uint16_t async_threshold;
+
+ int notif_enable;
+#define VIRTIO_UNINITIALIZED_NOTIF (-1)
+
+ struct vhost_vring_addr ring_addrs;
} __rte_cache_aligned;
/* Virtio device status as per Virtio specification */
@@ -406,6 +406,11 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
if (validate_msg_fds(msg, 0) != 0)
return RTE_VHOST_MSG_RESULT_ERR;
+ if (msg->payload.state.num > 32768) {
+ VHOST_LOG_CONFIG(ERR, "invalid virtqueue size %u\n", msg->payload.state.num);
+ return RTE_VHOST_MSG_RESULT_ERR;
+ }
+
vq->size = msg->payload.state.num;
/* VIRTIO 1.0, 2.4 Virtqueues says:
@@ -425,12 +430,6 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
}
}
- if (vq->size > 32768) {
- VHOST_LOG_CONFIG(ERR,
- "invalid virtqueue size %u\n", vq->size);
- return RTE_VHOST_MSG_RESULT_ERR;
- }
-
if (vq_is_packed(dev)) {
if (vq->shadow_used_packed)
rte_free(vq->shadow_used_packed);
@@ -713,7 +712,7 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
return dev;
}
- vq->access_ok = 1;
+ vq->access_ok = true;
return dev;
}
@@ -771,7 +770,7 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
vq->last_avail_idx = vq->used->idx;
}
- vq->access_ok = 1;
+ vq->access_ok = true;
VHOST_LOG_CONFIG(DEBUG, "(%d) mapped address desc: %p\n",
dev->vid, vq->desc);
@@ -1918,7 +1917,7 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
* the SET_VRING_ENABLE message.
*/
if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
- vq->enabled = 1;
+ vq->enabled = true;
if (dev->notify_ops->vring_state_changed)
dev->notify_ops->vring_state_changed(
dev->vid, file.index, 1);
@@ -2043,7 +2042,7 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
int main_fd __rte_unused)
{
struct virtio_net *dev = *pdev;
- int enable = (int)msg->payload.state.num;
+ bool enable = !!msg->payload.state.num;
int index = (int)msg->payload.state.index;
if (validate_msg_fds(msg, 0) != 0)
@@ -1396,13 +1396,13 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
rte_spinlock_lock(&vq->access_lock);
- if (unlikely(vq->enabled == 0))
+ if (unlikely(!vq->enabled))
goto out_access_unlock;
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
vhost_user_iotlb_rd_lock(vq);
- if (unlikely(vq->access_ok == 0))
+ if (unlikely(!vq->access_ok))
if (unlikely(vring_translate(dev, vq) < 0))
goto out;
@@ -1753,13 +1753,13 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
rte_spinlock_lock(&vq->access_lock);
- if (unlikely(vq->enabled == 0 || !vq->async_registered))
+ if (unlikely(!vq->enabled || !vq->async_registered))
goto out_access_unlock;
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
vhost_user_iotlb_rd_lock(vq);
- if (unlikely(vq->access_ok == 0))
+ if (unlikely(!vq->access_ok))
if (unlikely(vring_translate(dev, vq) < 0))
goto out;
@@ -2518,7 +2518,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
return 0;
- if (unlikely(vq->enabled == 0)) {
+ if (unlikely(!vq->enabled)) {
count = 0;
goto out_access_unlock;
}
@@ -2526,7 +2526,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
vhost_user_iotlb_rd_lock(vq);
- if (unlikely(vq->access_ok == 0))
+ if (unlikely(!vq->access_ok))
if (unlikely(vring_translate(dev, vq) < 0)) {
count = 0;
goto out;