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-rw-r--r--hw/virtio/dataplane/vring.c56
1 files changed, 36 insertions, 20 deletions
diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
index d81b653399..1bf9dd335a 100644
--- a/hw/virtio/dataplane/vring.c
+++ b/hw/virtio/dataplane/vring.c
@@ -111,29 +111,32 @@ bool vring_should_notify(VirtIODevice *vdev, Vring *vring)
}
-static int get_desc(Vring *vring,
- struct iovec iov[], struct iovec *iov_end,
- unsigned int *out_num, unsigned int *in_num,
+static int get_desc(Vring *vring, VirtQueueElement *elem,
struct vring_desc *desc)
{
unsigned *num;
+ struct iovec *iov;
+ hwaddr *addr;
if (desc->flags & VRING_DESC_F_WRITE) {
- num = in_num;
+ num = &elem->in_num;
+ iov = &elem->in_sg[*num];
+ addr = &elem->in_addr[*num];
} else {
- num = out_num;
+ num = &elem->out_num;
+ iov = &elem->out_sg[*num];
+ addr = &elem->out_addr[*num];
/* If it's an output descriptor, they're all supposed
* to come before any input descriptors. */
- if (unlikely(*in_num)) {
+ if (unlikely(elem->in_num)) {
error_report("Descriptor has out after in");
return -EFAULT;
}
}
/* Stop for now if there are not enough iovecs available. */
- iov += *in_num + *out_num;
- if (iov >= iov_end) {
+ if (*num >= VIRTQUEUE_MAX_SIZE) {
return -ENOBUFS;
}
@@ -147,14 +150,13 @@ static int get_desc(Vring *vring,
}
iov->iov_len = desc->len;
+ *addr = desc->addr;
*num += 1;
return 0;
}
/* This is stolen from linux/drivers/vhost/vhost.c. */
-static int get_indirect(Vring *vring,
- struct iovec iov[], struct iovec *iov_end,
- unsigned int *out_num, unsigned int *in_num,
+static int get_indirect(Vring *vring, VirtQueueElement *elem,
struct vring_desc *indirect)
{
struct vring_desc desc;
@@ -212,7 +214,7 @@ static int get_indirect(Vring *vring,
return -EFAULT;
}
- ret = get_desc(vring, iov, iov_end, out_num, in_num, &desc);
+ ret = get_desc(vring, elem, &desc);
if (ret < 0) {
vring->broken |= (ret == -EFAULT);
return ret;
@@ -222,6 +224,11 @@ static int get_indirect(Vring *vring,
return 0;
}
+void vring_free_element(VirtQueueElement *elem)
+{
+ g_slice_free(VirtQueueElement, elem);
+}
+
/* This looks in the virtqueue and for the first available buffer, and converts
* it to an iovec for convenient access. Since descriptors consist of some
* number of output then some number of input descriptors, it's actually two
@@ -234,12 +241,12 @@ static int get_indirect(Vring *vring,
* Stolen from linux/drivers/vhost/vhost.c.
*/
int vring_pop(VirtIODevice *vdev, Vring *vring,
- struct iovec iov[], struct iovec *iov_end,
- unsigned int *out_num, unsigned int *in_num)
+ VirtQueueElement **p_elem)
{
struct vring_desc desc;
unsigned int i, head, found = 0, num = vring->vr.num;
uint16_t avail_idx, last_avail_idx;
+ VirtQueueElement *elem = NULL;
int ret;
/* If there was a fatal error then refuse operation */
@@ -273,6 +280,10 @@ int vring_pop(VirtIODevice *vdev, Vring *vring,
* the index we've seen. */
head = vring->vr.avail->ring[last_avail_idx % num];
+ elem = g_slice_new(VirtQueueElement);
+ elem->index = head;
+ elem->in_num = elem->out_num = 0;
+
/* If their number is silly, that's an error. */
if (unlikely(head >= num)) {
error_report("Guest says index %u > %u is available", head, num);
@@ -284,9 +295,6 @@ int vring_pop(VirtIODevice *vdev, Vring *vring,
vring_avail_event(&vring->vr) = vring->vr.avail->idx;
}
- /* When we start there are none of either input nor output. */
- *out_num = *in_num = 0;
-
i = head;
do {
if (unlikely(i >= num)) {
@@ -306,14 +314,14 @@ int vring_pop(VirtIODevice *vdev, Vring *vring,
barrier();
if (desc.flags & VRING_DESC_F_INDIRECT) {
- int ret = get_indirect(vring, iov, iov_end, out_num, in_num, &desc);
+ int ret = get_indirect(vring, elem, &desc);
if (ret < 0) {
goto out;
}
continue;
}
- ret = get_desc(vring, iov, iov_end, out_num, in_num, &desc);
+ ret = get_desc(vring, elem, &desc);
if (ret < 0) {
goto out;
}
@@ -323,6 +331,7 @@ int vring_pop(VirtIODevice *vdev, Vring *vring,
/* On success, increment avail index. */
vring->last_avail_idx++;
+ *p_elem = elem;
return head;
out:
@@ -330,6 +339,10 @@ out:
if (ret == -EFAULT) {
vring->broken = true;
}
+ if (elem) {
+ vring_free_element(elem);
+ }
+ *p_elem = NULL;
return ret;
}
@@ -337,11 +350,14 @@ out:
*
* Stolen from linux/drivers/vhost/vhost.c.
*/
-void vring_push(Vring *vring, unsigned int head, int len)
+void vring_push(Vring *vring, VirtQueueElement *elem, int len)
{
struct vring_used_elem *used;
+ unsigned int head = elem->index;
uint16_t new;
+ vring_free_element(elem);
+
/* Don't touch vring if a fatal error occurred */
if (vring->broken) {
return;