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-rw-r--r--hw/virtio/virtio-stub.c9
-rw-r--r--hw/virtio/virtio.c154
-rw-r--r--qapi/virtio.json197
3 files changed, 360 insertions, 0 deletions
diff --git a/hw/virtio/virtio-stub.c b/hw/virtio/virtio-stub.c
index 13e5f93652..7ddb22cc5e 100644
--- a/hw/virtio/virtio-stub.c
+++ b/hw/virtio/virtio-stub.c
@@ -31,3 +31,12 @@ VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path,
{
return qmp_virtio_unsupported(errp);
}
+
+VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path,
+ uint16_t queue,
+ bool has_index,
+ uint16_t index,
+ Error **errp)
+{
+ return qmp_virtio_unsupported(errp);
+}
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,
diff --git a/qapi/virtio.json b/qapi/virtio.json
index d9050f3584..e47a8fb2e0 100644
--- a/qapi/virtio.json
+++ b/qapi/virtio.json
@@ -755,3 +755,200 @@
'data': { 'path': 'str', 'queue': 'uint16' },
'returns': 'VirtVhostQueueStatus',
'features': [ 'unstable' ] }
+
+##
+# @VirtioRingDesc:
+#
+# Information regarding the vring descriptor area
+#
+# @addr: Guest physical address of the descriptor area
+#
+# @len: Length of the descriptor area
+#
+# @flags: List of descriptor flags
+#
+# Since: 7.1
+#
+##
+
+{ 'struct': 'VirtioRingDesc',
+ 'data': { 'addr': 'uint64',
+ 'len': 'uint32',
+ 'flags': [ 'str' ] } }
+
+##
+# @VirtioRingAvail:
+#
+# Information regarding the avail vring (a.k.a. driver area)
+#
+# @flags: VRingAvail flags
+#
+# @idx: VRingAvail index
+#
+# @ring: VRingAvail ring[] entry at provided index
+#
+# Since: 7.1
+#
+##
+
+{ 'struct': 'VirtioRingAvail',
+ 'data': { 'flags': 'uint16',
+ 'idx': 'uint16',
+ 'ring': 'uint16' } }
+
+##
+# @VirtioRingUsed:
+#
+# Information regarding the used vring (a.k.a. device area)
+#
+# @flags: VRingUsed flags
+#
+# @idx: VRingUsed index
+#
+# Since: 7.1
+#
+##
+
+{ 'struct': 'VirtioRingUsed',
+ 'data': { 'flags': 'uint16',
+ 'idx': 'uint16' } }
+
+##
+# @VirtioQueueElement:
+#
+# Information regarding a VirtQueue's VirtQueueElement including
+# descriptor, driver, and device areas
+#
+# @name: Name of the VirtIODevice that uses this VirtQueue
+#
+# @index: Index of the element in the queue
+#
+# @descs: List of descriptors (VirtioRingDesc)
+#
+# @avail: VRingAvail info
+#
+# @used: VRingUsed info
+#
+# Since: 7.1
+#
+##
+
+{ 'struct': 'VirtioQueueElement',
+ 'data': { 'name': 'str',
+ 'index': 'uint32',
+ 'descs': [ 'VirtioRingDesc' ],
+ 'avail': 'VirtioRingAvail',
+ 'used': 'VirtioRingUsed' } }
+
+##
+# @x-query-virtio-queue-element:
+#
+# Return the information about a VirtQueue's VirtQueueElement
+#
+# @path: VirtIODevice canonical QOM path
+#
+# @queue: VirtQueue index to examine
+#
+# @index: Index of the element in the queue
+# (default: head of the queue)
+#
+# Features:
+# @unstable: This command is meant for debugging.
+#
+# Returns: VirtioQueueElement information
+#
+# Since: 7.1
+#
+# Examples:
+#
+# 1. Introspect on virtio-net's VirtQueue 0 at index 5
+#
+# -> { "execute": "x-query-virtio-queue-element",
+# "arguments": { "path": "/machine/peripheral-anon/device[1]/virtio-backend",
+# "queue": 0,
+# "index": 5 }
+# }
+# <- { "return": {
+# "index": 5,
+# "name": "virtio-net",
+# "descs": [
+# {
+# "flags": ["write"],
+# "len": 1536,
+# "addr": 5257305600
+# }
+# ],
+# "avail": {
+# "idx": 256,
+# "flags": 0,
+# "ring": 5
+# },
+# "used": {
+# "idx": 13,
+# "flags": 0
+# }
+# }
+# }
+#
+# 2. Introspect on virtio-crypto's VirtQueue 1 at head
+#
+# -> { "execute": "x-query-virtio-queue-element",
+# "arguments": { "path": "/machine/peripheral/crypto0/virtio-backend",
+# "queue": 1 }
+# }
+# <- { "return": {
+# "index": 0,
+# "name": "virtio-crypto",
+# "descs": [
+# {
+# "flags": [],
+# "len": 0,
+# "addr": 8080268923184214134
+# }
+# ],
+# "avail": {
+# "idx": 280,
+# "flags": 0,
+# "ring": 0
+# },
+# "used": {
+# "idx": 280,
+# "flags": 0
+# }
+# }
+# }
+#
+# 3. Introspect on virtio-scsi's VirtQueue 2 at head
+#
+# -> { "execute": "x-query-virtio-queue-element",
+# "arguments": { "path": "/machine/peripheral-anon/device[2]/virtio-backend",
+# "queue": 2 }
+# }
+# <- { "return": {
+# "index": 19,
+# "name": "virtio-scsi",
+# "descs": [
+# {
+# "flags": ["used", "indirect", "write"],
+# "len": 4099327944,
+# "addr": 12055409292258155293
+# }
+# ],
+# "avail": {
+# "idx": 1147,
+# "flags": 0,
+# "ring": 19
+# },
+# "used": {
+# "idx": 280,
+# "flags": 0
+# }
+# }
+# }
+#
+##
+
+{ 'command': 'x-query-virtio-queue-element',
+ 'data': { 'path': 'str', 'queue': 'uint16', '*index': 'uint16' },
+ 'returns': 'VirtioQueueElement',
+ 'features': [ 'unstable' ] }
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-25 15:45:45 +0000