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authorKevin Wolf <kwolf@redhat.com>2021-04-29 19:13:16 +0200
committerKevin Wolf <kwolf@redhat.com>2021-05-18 12:57:39 +0200
commitc90bd505a3e8210c23d69fecab9ee6f56ec4a161 (patch)
tree4047a26f0dd7de9f3c6ea510790af7b20f8b65ea
parent04ceb61a4075fadbf374ef89662c41999da83489 (diff)
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vhost-user-blk: Check that num-queues is supported by backend
Creating a device with a number of queues that isn't supported by the backend is pointless, the device won't work properly and the error messages are rather confusing. Just fail to create the device if num-queues is higher than what the backend supports. Since the relationship between num-queues and the number of virtqueues depends on the specific device, this is an additional value that needs to be initialised by the device. For convenience, allow leaving it 0 if the check should be skipped. This makes sense for vhost-user-net where separate vhost devices are used for the queues and custom initialisation code is needed to perform the check. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1935031 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com> Message-Id: <20210429171316.162022-7-kwolf@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--hw/block/vhost-user-blk.c1
-rw-r--r--hw/virtio/vhost-user.c5
-rw-r--r--include/hw/virtio/vhost.h2
3 files changed, 8 insertions, 0 deletions
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index c7e502f..c6210fa 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -324,6 +324,7 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
}
s->connected = true;
+ s->dev.num_queues = s->num_queues;
s->dev.nvqs = s->num_queues;
s->dev.vqs = s->vhost_vqs;
s->dev.vq_index = 0;
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index ded0c10..ee57abe 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1909,6 +1909,11 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
return err;
}
}
+ if (dev->num_queues && dev->max_queues < dev->num_queues) {
+ error_report("The maximum number of queues supported by the "
+ "backend is %" PRIu64, dev->max_queues);
+ return -EINVAL;
+ }
if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
!(virtio_has_feature(dev->protocol_features,
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 4a8bc75..21a9a52 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -74,6 +74,8 @@ struct vhost_dev {
int nvqs;
/* the first virtqueue which would be used by this vhost dev */
int vq_index;
+ /* if non-zero, minimum required value for max_queues */
+ int num_queues;
uint64_t features;
uint64_t acked_features;
uint64_t backend_features;