This makes little difference, but it makes the code change smaller
for the next patch that introduces MemoryRegionCache. This is
because map/unmap are similar to MemoryRegionCache init/destroy.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/virtio/virtio.c | 76 ++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 57 insertions(+), 19 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index b1c5563..7a49f2e 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -120,10 +120,9 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n)
}
static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc,
- hwaddr desc_pa, int i)
+ uint8_t *desc_ptr, int i)
{
- address_space_read(vdev->dma_as, desc_pa + i * sizeof(VRingDesc),
- MEMTXATTRS_UNSPECIFIED, (void *)desc,
sizeof(VRingDesc));
+ memcpy(desc, desc_ptr + i * sizeof(VRingDesc), sizeof(VRingDesc));
virtio_tswap64s(vdev, &desc->addr);
virtio_tswap32s(vdev, &desc->len);
virtio_tswap16s(vdev, &desc->flags);
@@ -408,7 +407,7 @@ enum {
};
static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
- hwaddr desc_pa, unsigned int max,
+ void *desc_ptr, unsigned int max,
unsigned int *next)
{
/* If this descriptor says it doesn't chain, we're done. */
@@ -426,7 +425,7 @@ static int virtqueue_read_next_desc(VirtIODevice *vdev,
VRingDesc *desc,
return VIRTQUEUE_READ_DESC_ERROR;
}
- vring_desc_read(vdev, desc, desc_pa, *next);
+ vring_desc_read(vdev, desc, desc_ptr, *next);
return VIRTQUEUE_READ_DESC_MORE;
}
@@ -434,18 +433,19 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned
int *in_bytes,
unsigned int *out_bytes,
unsigned max_in_bytes, unsigned max_out_bytes)
{
+ VirtIODevice *vdev = vq->vdev;
unsigned int idx;
unsigned int total_bufs, in_total, out_total;
+ void *desc_ptr = NULL;
+ hwaddr len = 0;
int rc;
idx = vq->last_avail_idx;
total_bufs = in_total = out_total = 0;
while ((rc = virtqueue_num_heads(vq, idx)) > 0) {
- VirtIODevice *vdev = vq->vdev;
unsigned int max, num_bufs, indirect = 0;
VRingDesc desc;
- hwaddr desc_pa;
unsigned int i;
max = vq->vring.num;
@@ -455,10 +455,18 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned
int *in_bytes,
goto err;
}
- desc_pa = vq->vring.desc;
- vring_desc_read(vdev, &desc, desc_pa, i);
+ len = max * sizeof(VRingDesc);
+ desc_ptr = address_space_map(vdev->dma_as, vq->vring.desc, &len,
false);
+ if (len < max * sizeof(VRingDesc)) {
+ virtio_error(vdev, "Cannot map descriptor ring");
+ goto err;
+ }
+
+ vring_desc_read(vdev, &desc, desc_ptr, i);
if (desc.flags & VRING_DESC_F_INDIRECT) {
+ address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0);
+ len = desc.len;
if (desc.len % sizeof(VRingDesc)) {
virtio_error(vdev, "Invalid size for indirect buffer table");
goto err;
@@ -471,11 +479,16 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned
int *in_bytes,
}
/* loop over the indirect descriptor table */
+ desc_ptr = address_space_map(vdev->dma_as, desc.addr, &len, false);
+ if (len < desc.len) {
+ virtio_error(vdev, "Cannot map indirect buffer");
+ goto err;
+ }
+
indirect = 1;
max = desc.len / sizeof(VRingDesc);
- desc_pa = desc.addr;
num_bufs = i = 0;
- vring_desc_read(vdev, &desc, desc_pa, i);
+ vring_desc_read(vdev, &desc, desc_ptr, i);
}
do {
@@ -494,7 +507,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int
*in_bytes,
goto done;
}
- rc = virtqueue_read_next_desc(vdev, &desc, desc_pa, max, &i);
+ rc = virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i);
} while (rc == VIRTQUEUE_READ_DESC_MORE);
if (rc == VIRTQUEUE_READ_DESC_ERROR) {
@@ -512,6 +525,9 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int
*in_bytes,
}
done:
+ if (desc_ptr) {
+ address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0);
+ }
if (in_bytes) {
*in_bytes = in_total;
}
@@ -651,9 +667,10 @@ static void *virtqueue_alloc_element(size_t sz, unsigned
out_num, unsigned in_nu
void *virtqueue_pop(VirtQueue *vq, size_t sz)
{
unsigned int i, head, max;
- hwaddr desc_pa = vq->vring.desc;
+ void *desc_ptr = NULL;
+ hwaddr len;
VirtIODevice *vdev = vq->vdev;
- VirtQueueElement *elem;
+ VirtQueueElement *elem = NULL;
unsigned out_num, in_num;
hwaddr addr[VIRTQUEUE_MAX_SIZE];
struct iovec iov[VIRTQUEUE_MAX_SIZE];
@@ -689,18 +706,33 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
}
i = head;
- vring_desc_read(vdev, &desc, desc_pa, i);
+
+ len = max * sizeof(VRingDesc);
+ desc_ptr = address_space_map(vdev->dma_as, vq->vring.desc, &len, false);
+ if (len < max * sizeof(VRingDesc)) {
+ virtio_error(vdev, "Cannot map descriptor ring");
+ return NULL;
+ }
+
+ vring_desc_read(vdev, &desc, desc_ptr, i);
if (desc.flags & VRING_DESC_F_INDIRECT) {
+ address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0);
if (desc.len % sizeof(VRingDesc)) {
virtio_error(vdev, "Invalid size for indirect buffer table");
return NULL;
}
/* loop over the indirect descriptor table */
+ len = desc.len;
+ desc_ptr = address_space_map(vdev->dma_as, desc.addr, &len, false);
+ if (len < desc.len) {
+ virtio_error(vdev, "Cannot map indirect buffer");
+ return NULL;
+ }
+
max = desc.len / sizeof(VRingDesc);
- desc_pa = desc.addr;
i = 0;
- vring_desc_read(vdev, &desc, desc_pa, i);
+ vring_desc_read(vdev, &desc, desc_ptr, i);
}
/* Collect all the descriptors */
@@ -731,7 +763,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
goto err_undo_map;
}
- rc = virtqueue_read_next_desc(vdev, &desc, desc_pa, max, &i);
+ rc = virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i);
} while (rc == VIRTQUEUE_READ_DESC_MORE);
if (rc == VIRTQUEUE_READ_DESC_ERROR) {
@@ -753,11 +785,17 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
vq->inuse++;
trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
+done:
+ if (desc_ptr) {
+ address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0);
+ }
+
return elem;
err_undo_map:
virtqueue_undo_map_desc(out_num, in_num, iov);
- return NULL;
+ elem = NULL;
+ goto done;
}
/* virtqueue_drop_all:
--
2.9.3
