From fb20fbb764aa1eb3014c7544ea3daa58bc7b4cd2 Mon Sep 17 00:00:00 2001 From: Jia He Date: Wed, 28 Feb 2018 01:35:28 -0800 Subject: [PATCH] vhost: avoid to start/stop virtqueue which is not ready In our Armv8a server, we try to configure the vhost scsi but fail to boot up the guest (-machine virt-2.10). The guest's boot failure is very early, even earlier than grub. There are 3 virtqueues (ctrl, event and cmd) for virtio scsi device, but ovmf and seabios will only set the physical address for the 3rd one (cmd). Then in vhost_virtqueue_start(), virtio_queue_get_desc_addr will be 0 for ctrl and event vq when qemu negotiates with ovmf. So vhost_memory_map fails with ENOMEM. This patch just fixs it by early quitting the virtqueue start/stop when virtio_queue_get_desc_addr is 0. Btw, after guest kernel starts, all the 3 queues will be initialized and set address correctly. Already tested on Arm64 and X86_64 qemu. Signed-off-by: Jia He Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 4a583a3c1e..d02d12a861 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -345,6 +345,10 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev, for (i = 0; i < dev->nvqs; ++i) { struct vhost_virtqueue *vq = dev->vqs + i; + if (vq->desc_phys == 0) { + continue; + } + j = 0; r = vhost_verify_ring_part_mapping( vq->desc, vq->desc_phys, vq->desc_size, @@ -881,6 +885,11 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, }; struct VirtQueue *vvq = virtio_get_queue(vdev, idx); + a = virtio_queue_get_desc_addr(vdev, idx); + if (a == 0) { + /* Queue might not be ready for start */ + return 0; + } vq->num = state.num = virtio_queue_get_num(vdev, idx); r = dev->vhost_ops->vhost_set_vring_num(dev, &state); @@ -906,7 +915,7 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, } vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx); - vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx); + vq->desc_phys = a; vq->desc = vhost_memory_map(dev, a, &l, 0); if (!vq->desc || l != s) { r = -ENOMEM; @@ -989,6 +998,13 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev, .index = vhost_vq_index, }; int r; + int a; + + a = virtio_queue_get_desc_addr(vdev, idx); + if (a == 0) { + /* Don't stop the virtqueue which might have not been started */ + return; + } r = dev->vhost_ops->vhost_get_vring_base(dev, &state); if (r < 0) { -- GitLab