diff options
Diffstat (limited to 'hw/virtio/virtio.c')
| -rw-r--r-- | hw/virtio/virtio.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index da869e7b51..808446b4c9 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -823,6 +823,19 @@ static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); } +/* Called within rcu_read_lock(). */ +static inline uint16_t vring_used_flags(VirtQueue *vq) +{ + VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); + hwaddr pa = offsetof(VRingUsed, flags); + + if (!caches) { + return 0; + } + + return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); +} + /* Called within rcu_read_lock(). */ static uint16_t vring_used_idx(VirtQueue *vq) { @@ -4782,6 +4795,147 @@ VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path, return status; } +static strList *qmp_decode_vring_desc_flags(uint16_t flags) +{ + strList *list = NULL; + strList *node; + int i; + + struct { + uint16_t flag; + const char *value; + } map[] = { + { VRING_DESC_F_NEXT, "next" }, + { VRING_DESC_F_WRITE, "write" }, + { VRING_DESC_F_INDIRECT, "indirect" }, + { 1 << VRING_PACKED_DESC_F_AVAIL, "avail" }, + { 1 << VRING_PACKED_DESC_F_USED, "used" }, + { 0, "" } + }; + + for (i = 0; map[i].flag; i++) { + if ((map[i].flag & flags) == 0) { + continue; + } + node = g_malloc0(sizeof(strList)); + node->value = g_strdup(map[i].value); + node->next = list; + list = node; + } + + return list; +} + +VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path, + uint16_t queue, + bool has_index, + uint16_t index, + Error **errp) +{ + VirtIODevice *vdev; + VirtQueue *vq; + VirtioQueueElement *element = NULL; + + vdev = virtio_device_find(path); + if (vdev == NULL) { + error_setg(errp, "Path %s is not a VirtIO device", path); + return NULL; + } + + if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { + error_setg(errp, "Invalid virtqueue number %d", queue); + return NULL; + } + vq = &vdev->vq[queue]; + + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { + error_setg(errp, "Packed ring not supported"); + return NULL; + } else { + unsigned int head, i, max; + VRingMemoryRegionCaches *caches; + MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; + MemoryRegionCache *desc_cache; + VRingDesc desc; + VirtioRingDescList *list = NULL; + VirtioRingDescList *node; + int rc; int ndescs; + + RCU_READ_LOCK_GUARD(); + + max = vq->vring.num; + + if (!has_index) { + head = vring_avail_ring(vq, vq->last_avail_idx % vq->vring.num); + } else { + head = vring_avail_ring(vq, index % vq->vring.num); + } + i = head; + + caches = vring_get_region_caches(vq); + if (!caches) { + error_setg(errp, "Region caches not initialized"); + return NULL; + } + if (caches->desc.len < max * sizeof(VRingDesc)) { + error_setg(errp, "Cannot map descriptor ring"); + return NULL; + } + + desc_cache = &caches->desc; + vring_split_desc_read(vdev, &desc, desc_cache, i); + if (desc.flags & VRING_DESC_F_INDIRECT) { + int64_t len; + len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, + desc.addr, desc.len, false); + desc_cache = &indirect_desc_cache; + if (len < desc.len) { + error_setg(errp, "Cannot map indirect buffer"); + goto done; + } + + max = desc.len / sizeof(VRingDesc); + i = 0; + vring_split_desc_read(vdev, &desc, desc_cache, i); + } + + element = g_new0(VirtioQueueElement, 1); + element->avail = g_new0(VirtioRingAvail, 1); + element->used = g_new0(VirtioRingUsed, 1); + element->name = g_strdup(vdev->name); + element->index = head; + element->avail->flags = vring_avail_flags(vq); + element->avail->idx = vring_avail_idx(vq); + element->avail->ring = head; + element->used->flags = vring_used_flags(vq); + element->used->idx = vring_used_idx(vq); + ndescs = 0; + + do { + /* A buggy driver may produce an infinite loop */ + if (ndescs >= max) { + break; + } + node = g_new0(VirtioRingDescList, 1); + node->value = g_new0(VirtioRingDesc, 1); + node->value->addr = desc.addr; + node->value->len = desc.len; + node->value->flags = qmp_decode_vring_desc_flags(desc.flags); + node->next = list; + list = node; + + ndescs++; + rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, + max, &i); + } while (rc == VIRTQUEUE_READ_DESC_MORE); + element->descs = list; +done: + address_space_cache_destroy(&indirect_desc_cache); + } + + return element; +} + static const TypeInfo virtio_device_info = { .name = TYPE_VIRTIO_DEVICE, .parent = TYPE_DEVICE, |