[PATCH v2 0/3] vhost-vsock: force virtio version 1

From: Stefano Garzarella <sgarzare@redhat.com>
To: qemu-devel@nongnu.org
Cc: Thomas Huth <thuth@redhat.com>, Qinghua Cheng <qcheng@redhat.com>,
	Qian Cai <caiqian@redhat.com>,
	David Hildenbrand <david@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	qemu-stable@nongnu.org, Halil Pasic <pasic@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	qemu-s390x@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>,
	Richard Henderson <rth@twiddle.net>
Subject: [PATCH v2 0/3] vhost-vsock: force virtio version 1
Date: Wed, 19 Aug 2020 16:38:48 +0200	[thread overview]
Message-ID: <20200819143851.78069-1-sgarzare@redhat.com> (raw)

v2:
   - Fixed commit message in patche 1 and 2 [Cornelia]
   - Added Cornelia's R-b tags in all patches

v1: https://lists.gnu.org/archive/html/qemu-devel/2020-08/msg04373.html

Recenlty changes in QEMU 5.1 requires to set 'disable-legacy=on'
on vhost-vsock-pci and vhost-user-vsock-pci devices:

    $ ./qemu-system-x86_64 ... -device vhost-vsock-pci,guest-cid=5
        qemu-system-x86_64: -device vhost-vsock-pci,guest-cid=5:
        device is modern-only, use disable-legacy=on

As discussed with Cornelia [1], this series force virtio version 1
to vhost-vsock-pci, vhost-user-vsock-pci, and vhost-vsock-ccw devices.

virtio-vsock was introduced after the release of VIRTIO 1.0 specifications,
so it should be 'modern-only'.
In addition Cornelia verified that forcing a legacy mode on vhost-vsock-pci
device using x86-64 host and s390x guest, so with different endianness,
produces strange behaviours.

About migration, QEMU 5.1 already requires that the source and destination
specify 'disable-legacy=on', otherwise the migration fails in this way:
    qemu-system-x86_64: get_pci_config_device: Bad config data: i=0x2 read: 12 device: 53 cmask: ff wmask: 0 w1cmask:0
    qemu-system-x86_64: Failed to load PCIDevice:config
    qemu-system-x86_64: Failed to load virtio-vhost_vsock:virtio
    qemu-system-x86_64: error while loading state for instance 0x0 of device '0000:00:03.0/virtio-vhost_vsock'
    qemu-system-x86_64: load of migration failed: Invalid argument

With this series applied there is the same requirements. Alternatively
we have to detach and re-attach the device manually.

Thanks,
Stefano

[1] https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg02515.html

Stefano Garzarella (3):
  vhost-vsock-pci: force virtio version 1
  vhost-user-vsock-pci: force virtio version 1
  vhost-vsock-ccw: force virtio version 1

 hw/s390x/vhost-vsock-ccw.c       | 2 ++
 hw/virtio/vhost-user-vsock-pci.c | 2 +-
 hw/virtio/vhost-vsock-pci.c      | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

-- 
2.26.2