id = 1318
title = "vsock device fails with \"qemu-system-x86_64: vhost_set_features failed: Operation not supported (95)\" when queue_reset=true"
state = "closed"
created_at = "2022-11-17T00:01:59.655Z"
closed_at = "2022-11-22T17:09:01.032Z"
labels = ["device:virtio", "kind::Bug"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1318"
host-os = "Fedora 37 (also occurs with Fedora 36)"
host-arch = "x86_64"
qemu-version = "built from commit 2c8311241d1f7377bb4ff76064b1d1fe15166413"
guest-os = "Minimal initramfs built from host using [mbuto](https://mbuto.sh).  Includes vsock driver, and  an init script starting `socat` to listen on a vsock and start `sshd -i"
guest-arch = "x86_64"
description = """Immediately after guest vsock driver initialize, qemu prints error messages.  I'm not able to connect to the guest with vsock:

```
[    0.654463] Run /init as init process
[    0.679778] NET: Registered PF_VSOCK protocol family
qemu-system-x86_64: vhost_set_features failed: Operation not supported (95)
qemu-system-x86_64: Error starting vhost: 95
ssh-keygen: generating new host keys: RSA DSA ECDSA ED25519 
# 
```"""
reproduce = """1. Clone `git://passt.top/passt`
2. In `passt/test`, run `make mbuto.img`
3. Run `qemu-system-x86_64 -enable-kvm -m 2048 -kernel KERNEL -initrd mbuto.img -nographic -serial stdio -nodefaults -append "console=ttyS0" -device vhost-vsock-pci,guest-cid=31415,queue_reset=true` replacing KERNEL with the host kernel image."""
additional = """- Problem goes away if `queue_reset=false`, which means it goes away with default options prior to `69e1c14aa222` ("virtio: core: vq reset feature negotation support")
- Occurs both with and without KVM"""