If the VM already has N(N>=8) available memory slots for vhost user, the VM will be crashed in vhost_user_set_mem_table if we try to hotplug the first vhost user NIC. This patch checks if memslot number exceeded or not after updating vhost_user_used_memslots.
Signed-off-by: Jay Zhou <jianjay.z...@huawei.com> --- hw/virtio/vhost.c | 40 ++++++++++++++++++++++++++++++---------- 1 file changed, 30 insertions(+), 10 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 0cf8a53..33aed1f 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1243,13 +1243,31 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) event_notifier_cleanup(&vq->masked_notifier); } +static bool vhost_dev_memslots_is_exceeded(struct vhost_dev *hdev) +{ + unsigned int n_memslots = 0; + + if (hdev->vhost_ops->vhost_get_used_memslots) { + n_memslots = hdev->vhost_ops->vhost_get_used_memslots(); + } else { + n_memslots = used_memslots; + } + + if (n_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { + error_report("vhost backend memory slots limit is less" + " than current number of present memory slots"); + return true; + } + + return false; +} + int vhost_dev_init(struct vhost_dev *hdev, void *opaque, VhostBackendType backend_type, uint32_t busyloop_timeout) { uint64_t features; int i, r, n_initialized_vqs = 0; Error *local_err = NULL; - unsigned int n_memslots = 0; hdev->vdev = NULL; hdev->migration_blocker = NULL; @@ -1262,15 +1280,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, goto fail; } - if (hdev->vhost_ops->vhost_get_used_memslots) { - n_memslots = hdev->vhost_ops->vhost_get_used_memslots(); - } else { - n_memslots = used_memslots; - } - - if (n_memslots > hdev->vhost_ops->vhost_backend_memslots_limit(hdev)) { - error_report("vhost backend memory slots limit is less" - " than current number of present memory slots"); + if (vhost_dev_memslots_is_exceeded(hdev)) { r = -1; goto fail; } @@ -1356,6 +1366,16 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, hdev->memory_changed = false; memory_listener_register(&hdev->memory_listener, &address_space_memory); QLIST_INSERT_HEAD(&vhost_devices, hdev, entry); + + if (vhost_dev_memslots_is_exceeded(hdev)) { + r = -1; + if (busyloop_timeout) { + goto fail_busyloop; + } else { + goto fail; + } + } + return 0; fail_busyloop: -- 1.8.3.1