diff options
| -rw-r--r-- | hw/virtio/virtio.c | 56 | ||||
| -rw-r--r-- | include/hw/virtio/virtio.h | 1 |
2 files changed, 48 insertions, 9 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index d0bc72e0e4..943b9904bc 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -448,28 +448,66 @@ int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, return in_bytes <= in_total && out_bytes <= out_total; } -void virtqueue_map_sg(struct iovec *sg, hwaddr *addr, - size_t num_sg, int is_write) +static void virtqueue_map_iovec(struct iovec *sg, hwaddr *addr, + unsigned int *num_sg, unsigned int max_size, + int is_write) { unsigned int i; hwaddr len; - if (num_sg > VIRTQUEUE_MAX_SIZE) { - error_report("virtio: map attempt out of bounds: %zd > %d", - num_sg, VIRTQUEUE_MAX_SIZE); - exit(1); - } + /* Note: this function MUST validate input, some callers + * are passing in num_sg values received over the network. + */ + /* TODO: teach all callers that this can fail, and return failure instead + * of asserting here. + * When we do, we might be able to re-enable NDEBUG below. + */ +#ifdef NDEBUG +#error building with NDEBUG is not supported +#endif + assert(*num_sg <= max_size); - for (i = 0; i < num_sg; i++) { + for (i = 0; i < *num_sg; i++) { len = sg[i].iov_len; sg[i].iov_base = cpu_physical_memory_map(addr[i], &len, is_write); - if (sg[i].iov_base == NULL || len != sg[i].iov_len) { + if (!sg[i].iov_base) { error_report("virtio: error trying to map MMIO memory"); exit(1); } + if (len == sg[i].iov_len) { + continue; + } + if (*num_sg >= max_size) { + error_report("virtio: memory split makes iovec too large"); + exit(1); + } + memmove(sg + i + 1, sg + i, sizeof(*sg) * (*num_sg - i)); + memmove(addr + i + 1, addr + i, sizeof(*addr) * (*num_sg - i)); + assert(len < sg[i + 1].iov_len); + sg[i].iov_len = len; + addr[i + 1] += len; + sg[i + 1].iov_len -= len; + ++*num_sg; } } +/* Deprecated: don't use in new code */ +void virtqueue_map_sg(struct iovec *sg, hwaddr *addr, + size_t num_sg, int is_write) +{ + virtqueue_map_iovec(sg, addr, &num_sg, num_sg, is_write); +} + +void virtqueue_map(VirtQueueElement *elem) +{ + virtqueue_map_iovec(elem->in_sg, elem->in_addr, &elem->in_num, + MIN(ARRAY_SIZE(elem->in_sg), ARRAY_SIZE(elem->in_addr)), + 1); + virtqueue_map_iovec(elem->out_sg, elem->out_addr, &elem->out_num, + MIN(ARRAY_SIZE(elem->out_sg), ARRAY_SIZE(elem->out_addr)), + 0); +} + int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) { unsigned int i, head, max; diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 9d09115fab..9d9abb4689 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -153,6 +153,7 @@ void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, void virtqueue_map_sg(struct iovec *sg, hwaddr *addr, size_t num_sg, int is_write); +void virtqueue_map(VirtQueueElement *elem); int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem); int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, unsigned int out_bytes); |