[RFC v2 04/10] vhost: add virtqueues groups support to VDUSE

Eugenio Pérez
2026-03-10T19:17:26Z

VDUSE API version 1 introduces the notion of virtqueue
groups, which once supported, enables the support of
multiple addresses spaces.

For VDUSE networking devices, we need two groups, one for
the datapath queues, and one for the control queue.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
lib/vhost/vduse.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index fc52b4cd0703..bb3a4363baad 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -38,12 +38,24 @@ static const char * const vduse_reqs_str[] = {
"VDUSE_GET_VQ_STATE",
"VDUSE_SET_STATUS",
"VDUSE_UPDATE_IOTLB",
+ "VDUSE_SET_VQ_GROUP_ASID",
};

#define vduse_req_id_to_str(id) \
(id < RTE_DIM(vduse_reqs_str) ? \
vduse_reqs_str[id] : "Unknown")

+static uint64_t vduse_vq_to_group(struct virtio_net *dev, struct vhost_virtqueue *vq)
+{
+ if (dev->vduse_api_ver < 1)
+ return 0;
+
+ if (vq == dev->cvq)
+ return 1;
+
+ return 0;
+}
+
static int
vduse_inject_irq(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
@@ -271,6 +283,7 @@ vduse_vring_cleanup(struct virtio_net *dev, unsigned int index)
vq->size = 0;
vq->last_used_idx = 0;
vq->last_avail_idx = 0;
+ vq->asid = 0;
}

/*
@@ -410,6 +423,7 @@ vduse_events_handler(int fd, void *arg, int *close __rte_unused)
struct vduse_dev_response resp;
struct vhost_virtqueue *vq;
uint8_t old_status = dev->status;
+ uint32_t i;
int ret;

memset(&resp, 0, sizeof(resp));
@@ -450,6 +464,26 @@ vduse_events_handler(int fd, void *arg, int *close __rte_unused)
req.iova.last - req.iova.start + 1); /* ToDo: use ASID once API available, using 0 for now */
resp.result = VDUSE_REQ_RESULT_OK;
break;
+ case VDUSE_SET_VQ_GROUP_ASID:
+ if (dev->vduse_api_ver < 1) {
+ resp.result = VDUSE_REQ_RESULT_FAILED;
+ break;
+ }
+
+ VHOST_CONFIG_LOG(dev->ifname, INFO, "\tAssigning ASID %d to group %d",
+ req.vq_group_asid.asid, req.vq_group_asid.group);
+
+ for (i = 0; i < dev->nr_vring; i++) {
+ vq = dev->virtqueue[i];
+
+ if (vduse_vq_to_group(dev, vq) == req.vq_group_asid.group) {
+ vq->asid = req.vq_group_asid.asid;
+ VHOST_CONFIG_LOG(dev->ifname, INFO, "\t\tVQ %d gets ASID %d",
+ i, req.vq_group_asid.asid);
+ }
+ }
+ resp.result = VDUSE_REQ_RESULT_OK;
+ break;
default:
resp.result = VDUSE_REQ_RESULT_FAILED;
break;
@@ -760,6 +794,10 @@ vduse_device_create(const char *path, bool compliant_ol_flags, bool extbuf, bool
dev_config->features = features;
dev_config->vq_num = total_queues;
dev_config->vq_align = rte_mem_page_size();
+ if (ver >= 1) {
+ dev_config->ngroups = 2;
+ dev_config->nas = 2;
+ }
dev_config->config_size = sizeof(struct virtio_net_config);
memcpy(dev_config->config, &vnet_config, sizeof(vnet_config));

@@ -848,11 +886,15 @@ vduse_device_create(const char *path, bool compliant_ol_flags, bool extbuf, bool
vq = dev->virtqueue[i];
vq->reconnect_log = &dev->reconnect_log->vring[i];

+ if (i == max_queue_pairs * 2)
+ dev->cvq = vq;
+
if (reconnect)
continue;

vq_cfg.index = i;
vq_cfg.max_size = 1024;
+ vq_cfg.group = vduse_vq_to_group(dev, vq);

ret = ioctl(dev->vduse_dev_fd, VDUSE_VQ_SETUP, &vq_cfg);
if (ret) {
@@ -861,8 +903,6 @@ vduse_device_create(const char *path, bool compliant_ol_flags, bool extbuf, bool
}
}

- dev->cvq = dev->virtqueue[max_queue_pairs * 2];
-
ret = fdset_add(vduse.fdset, dev->vduse_dev_fd, vduse_events_handler, NULL, dev);
if (ret) {
VHOST_CONFIG_LOG(name, ERR, "Failed to add fd %d to vduse fdset",
--
2.53.0