riscv
/
qemu
mirror of https://gitea.goldendeliverer.com/riscv/qemu.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
Browse Source

virtio: use address_space_map/unmap to access descriptors 

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.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
pull/42/merge
Paolo Bonzini 10 years ago
committed by Michael S. Tsirkin
parent
e6a830d6eb
commit
9796d0ac8f
1 changed files with 75 additions and 28 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 103
      hw/virtio/virtio.c

103
hw/virtio/virtio.c
View File

@ -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;
}
@ -434,31 +433,41 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
unsigned int *out_bytes,
unsigned max_in_bytes, unsigned max_out_bytes)
{
unsigned int idx;
VirtIODevice *vdev = vq->vdev;
unsigned int max, idx;
unsigned int total_bufs, in_total, out_total;
void *vring_desc_ptr;
void *indirect_desc_ptr = NULL;
hwaddr len = 0;
int rc;
idx = vq->last_avail_idx;
total_bufs = in_total = out_total = 0;
max = vq->vring.num;
len = max * sizeof(VRingDesc);
vring_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;
}
while ((rc = virtqueue_num_heads(vq, idx)) > 0) {
VirtIODevice *vdev = vq->vdev;
unsigned int max, num_bufs, indirect = 0;
void *desc_ptr = vring_desc_ptr;
unsigned int num_bufs;
VRingDesc desc;
hwaddr desc_pa;
unsigned int i;
max = vq->vring.num;
num_bufs = total_bufs;
if (!virtqueue_get_head(vq, idx++, &i)) {
goto err;
}
desc_pa = vq->vring.desc;
vring_desc_read(vdev, &desc, desc_pa, i);
vring_desc_read(vdev, &desc, desc_ptr, i);
if (desc.flags & VRING_DESC_F_INDIRECT) {
len = desc.len;
if (desc.len % sizeof(VRingDesc)) {
virtio_error(vdev, "Invalid size for indirect buffer table");
goto err;
@ -471,11 +480,17 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
}
/* loop over the indirect descriptor table */
indirect = 1;
indirect_desc_ptr = address_space_map(vdev->dma_as, desc.addr,
&len, false);
desc_ptr = indirect_desc_ptr;
if (len < desc.len) {
virtio_error(vdev, "Cannot map indirect buffer");
goto err;
}
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 {
@ -494,17 +509,20 @@ 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) {
goto err;
}
if (!indirect)
total_bufs = num_bufs;
else
if (desc_ptr == indirect_desc_ptr) {
address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0);
indirect_desc_ptr = NULL;
total_bufs++;
} else {
total_bufs = num_bufs;
}
}
if (rc < 0) {
@ -512,6 +530,10 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
}
done:
if (indirect_desc_ptr) {
address_space_unmap(vdev->dma_as, indirect_desc_ptr, len, false, 0);
}
address_space_unmap(vdev->dma_as, vring_desc_ptr, len, false, 0);
if (in_bytes) {
*in_bytes = in_total;
}
@ -651,9 +673,12 @@ 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 *vring_desc_ptr;
void *indirect_desc_ptr = NULL;
void *desc_ptr;
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 +714,34 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
}
i = head;
vring_desc_read(vdev, &desc, desc_pa, i);
len = max * sizeof(VRingDesc);
vring_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 done;
}
desc_ptr = vring_desc_ptr;
vring_desc_read(vdev, &desc, desc_ptr, i);
if (desc.flags & VRING_DESC_F_INDIRECT) {
if (desc.len % sizeof(VRingDesc)) {
virtio_error(vdev, "Invalid size for indirect buffer table");
return NULL;
goto done;
}
/* loop over the indirect descriptor table */
len = desc.len;
indirect_desc_ptr = address_space_map(vdev->dma_as, desc.addr, &len, false);
desc_ptr = indirect_desc_ptr;
if (len < desc.len) {
virtio_error(vdev, "Cannot map indirect buffer");
goto done;
}
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 +772,7 @@ 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 +794,17 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz)
vq->inuse++;
trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);
done:
if (indirect_desc_ptr) {
address_space_unmap(vdev->dma_as, indirect_desc_ptr, len, false, 0);
}
address_space_unmap(vdev->dma_as, vring_desc_ptr, len, false, 0);
return elem;
err_undo_map:
virtqueue_undo_map_desc(out_num, in_num, iov);
return NULL;
goto done;
}
/* virtqueue_drop_all:

Write Preview
Loading…
Cancel
Save