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hw/virtio: Have virtqueue_get_avail_bytes() pass caches arg to callees

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Both virtqueue_packed_get_avail_bytes() and
virtqueue_split_get_avail_bytes() access the region cache, but
their caller also does. Simplify by having virtqueue_get_avail_bytes
calling both with RCU lock held, and passing the caches as argument.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210906104318.1569967-4-philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
This commit is contained in:
Philippe Mathieu-Daudé 2021-09-06 12:43:18 +02:00 committed by Michael S. Tsirkin
parent ab4dd2746c
commit d6ed27bae7
1 changed files with 12 additions and 17 deletions
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29
hw/virtio/virtio.c
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@ -984,28 +984,23 @@ static int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
return VIRTQUEUE_READ_DESC_MORE;
}
/* Called within rcu_read_lock(). */
static void virtqueue_split_get_avail_bytes(VirtQueue *vq,
unsigned int *in_bytes, unsigned int *out_bytes,
unsigned max_in_bytes, unsigned max_out_bytes)
unsigned max_in_bytes, unsigned max_out_bytes,
VRingMemoryRegionCaches *caches)
{
VirtIODevice *vdev = vq->vdev;
unsigned int max, idx;
unsigned int total_bufs, in_total, out_total;
VRingMemoryRegionCaches *caches;
MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID;
int64_t len = 0;
int rc;
RCU_READ_LOCK_GUARD();
idx = vq->last_avail_idx;
total_bufs = in_total = out_total = 0;
max = vq->vring.num;
caches = vring_get_region_caches(vq);
if (!caches) {
goto err;
}
while ((rc = virtqueue_num_heads(vq, idx)) > 0) {
MemoryRegionCache *desc_cache = &caches->desc;
@ -1124,32 +1119,28 @@ static int virtqueue_packed_read_next_desc(VirtQueue *vq,
return VIRTQUEUE_READ_DESC_MORE;
}
/* Called within rcu_read_lock(). */
static void virtqueue_packed_get_avail_bytes(VirtQueue *vq,
unsigned int *in_bytes,
unsigned int *out_bytes,
unsigned max_in_bytes,
unsigned max_out_bytes)
unsigned max_out_bytes,
VRingMemoryRegionCaches *caches)
{
VirtIODevice *vdev = vq->vdev;
unsigned int max, idx;
unsigned int total_bufs, in_total, out_total;
MemoryRegionCache *desc_cache;
VRingMemoryRegionCaches *caches;
MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID;
int64_t len = 0;
VRingPackedDesc desc;
bool wrap_counter;
RCU_READ_LOCK_GUARD();
idx = vq->last_avail_idx;
wrap_counter = vq->last_avail_wrap_counter;
total_bufs = in_total = out_total = 0;
max = vq->vring.num;
caches = vring_get_region_caches(vq);
if (!caches) {
goto err;
}
for (;;) {
unsigned int num_bufs = total_bufs;
@ -1250,6 +1241,8 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
uint16_t desc_size;
VRingMemoryRegionCaches *caches;
RCU_READ_LOCK_GUARD();
if (unlikely(!vq->vring.desc)) {
goto err;
}
@ -1268,10 +1261,12 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
if (virtio_vdev_has_feature(vq->vdev, VIRTIO_F_RING_PACKED)) {
virtqueue_packed_get_avail_bytes(vq, in_bytes, out_bytes,
max_in_bytes, max_out_bytes);
max_in_bytes, max_out_bytes,
caches);
} else {
virtqueue_split_get_avail_bytes(vq, in_bytes, out_bytes,
max_in_bytes, max_out_bytes);
max_in_bytes, max_out_bytes,
caches);
}
return;