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[Qemu-devel] [PATCH v4 for-4.0 3/7] libvhost-user: Introduce vu_queue_ma
From: |
elohimes |
Subject: |
[Qemu-devel] [PATCH v4 for-4.0 3/7] libvhost-user: Introduce vu_queue_map_desc() |
Date: |
Wed, 9 Jan 2019 19:27:24 +0800 |
From: Xie Yongji <address@hidden>
Introduce vu_queue_map_desc() which should be
independent with vu_queue_pop();
Signed-off-by: Xie Yongji <address@hidden>
Signed-off-by: Zhang Yu <address@hidden>
Reviewed-by: Marc-André Lureau <address@hidden>
---
contrib/libvhost-user/libvhost-user.c | 88 ++++++++++++++++-----------
1 file changed, 51 insertions(+), 37 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index a6b46cdc03..23bd52264c 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -1853,49 +1853,20 @@ virtqueue_alloc_element(size_t sz,
return elem;
}
-void *
-vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
+static void *
+vu_queue_map_desc(VuDev *dev, VuVirtq *vq, unsigned int idx, size_t sz)
{
- unsigned int i, head, max, desc_len;
+ struct vring_desc *desc = vq->vring.desc;
uint64_t desc_addr, read_len;
+ unsigned int desc_len;
+ unsigned int max = vq->vring.num;
+ unsigned int i = idx;
VuVirtqElement *elem;
- unsigned out_num, in_num;
+ unsigned int out_num = 0, in_num = 0;
struct iovec iov[VIRTQUEUE_MAX_SIZE];
struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
- struct vring_desc *desc;
int rc;
- if (unlikely(dev->broken) ||
- unlikely(!vq->vring.avail)) {
- return NULL;
- }
-
- if (vu_queue_empty(dev, vq)) {
- return NULL;
- }
- /* Needed after virtio_queue_empty(), see comment in
- * virtqueue_num_heads(). */
- smp_rmb();
-
- /* When we start there are none of either input nor output. */
- out_num = in_num = 0;
-
- max = vq->vring.num;
- if (vq->inuse >= vq->vring.num) {
- vu_panic(dev, "Virtqueue size exceeded");
- return NULL;
- }
-
- if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
- return NULL;
- }
-
- if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
- vring_set_avail_event(vq, vq->last_avail_idx);
- }
-
- i = head;
- desc = vq->vring.desc;
if (desc[i].flags & VRING_DESC_F_INDIRECT) {
if (desc[i].len % sizeof(struct vring_desc)) {
vu_panic(dev, "Invalid size for indirect buffer table");
@@ -1947,12 +1918,13 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
} while (rc == VIRTQUEUE_READ_DESC_MORE);
if (rc == VIRTQUEUE_READ_DESC_ERROR) {
+ vu_panic(dev, "read descriptor error");
return NULL;
}
/* Now copy what we have collected and mapped */
elem = virtqueue_alloc_element(sz, out_num, in_num);
- elem->index = head;
+ elem->index = idx;
for (i = 0; i < out_num; i++) {
elem->out_sg[i] = iov[i];
}
@@ -1960,6 +1932,48 @@ vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
elem->in_sg[i] = iov[out_num + i];
}
+ return elem;
+}
+
+void *
+vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz)
+{
+ unsigned int head;
+ VuVirtqElement *elem;
+
+ if (unlikely(dev->broken) ||
+ unlikely(!vq->vring.avail)) {
+ return NULL;
+ }
+
+ if (vu_queue_empty(dev, vq)) {
+ return NULL;
+ }
+ /*
+ * Needed after virtio_queue_empty(), see comment in
+ * virtqueue_num_heads().
+ */
+ smp_rmb();
+
+ if (vq->inuse >= vq->vring.num) {
+ vu_panic(dev, "Virtqueue size exceeded");
+ return NULL;
+ }
+
+ if (!virtqueue_get_head(dev, vq, vq->last_avail_idx++, &head)) {
+ return NULL;
+ }
+
+ if (vu_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
+ vring_set_avail_event(vq, vq->last_avail_idx);
+ }
+
+ elem = vu_queue_map_desc(dev, vq, head, sz);
+
+ if (!elem) {
+ return NULL;
+ }
+
vq->inuse++;
return elem;
--
2.17.1
[Qemu-devel] [PATCH v4 for-4.0 2/7] vhost-user: Support transferring inflight buffer between qemu and backend, elohimes, 2019/01/09
[Qemu-devel] [PATCH v4 for-4.0 3/7] libvhost-user: Introduce vu_queue_map_desc(),
elohimes <=
[Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, elohimes, 2019/01/09
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Jason Wang, 2019/01/10
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Yongji Xie, 2019/01/11
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Jason Wang, 2019/01/15
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Yongji Xie, 2019/01/15
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Jason Wang, 2019/01/17
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Michael S. Tsirkin, 2019/01/17
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Jason Wang, 2019/01/17
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Yongji Xie, 2019/01/17
- Re: [Qemu-devel] [PATCH v4 for-4.0 4/7] libvhost-user: Support tracking inflight I/O in shared memory, Michael S. Tsirkin, 2019/01/17