[v1] virtio: features,fixes

[PULL 11/46] vhost-vsock: add VIRTIO_F_RING_PACKED to feature_bits

Michael S. Tsirkin posted 46 patches 5 months, 3 weeks ago

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Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Ani Sinha <anisinha@redhat.com>, Raphael Norwitz <raphael@enfabrica.net>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Jonathan Cameron <jonathan.cameron@huawei.com>, Fan Ni <fan.ni@samsung.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Jason Wang <jasowang@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, "Alex Bennée" <alex.bennee@linaro.org>, Stefan Hajnoczi <stefanha@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Laurent Vivier <lvivier@redhat.com>

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[PULL 11/46] vhost-vsock: add VIRTIO_F_RING_PACKED to feature_bits

Posted by Michael S. Tsirkin 5 months, 3 weeks ago

From: Halil Pasic <pasic@linux.ibm.com>

Not having VIRTIO_F_RING_PACKED in feature_bits[] is a problem when the
vhost-vsock device does not offer the feature bit VIRTIO_F_RING_PACKED
but the in QEMU device is configured to try to use the packed layout
(the virtio property "packed" is on).

As of today, the  Linux kernel vhost-vsock device does not support the
packed queue layout (as vhost does not support packed), and does not
offer VIRTIO_F_RING_PACKED. Thus when for example a vhost-vsock-ccw is
used with packed=on, VIRTIO_F_RING_PACKED ends up being negotiated,
despite the fact that the device does not actually support it, and
one gets to keep the pieces.

Fixes: 74b3e46630 ("virtio: add property to enable packed virtqueue")
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Message-Id: <20240429113334.2454197-1-pasic@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-vsock-common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/virtio/vhost-vsock-common.c b/hw/virtio/vhost-vsock-common.c
index 12ea87d7a7..fd88df2560 100644
--- a/hw/virtio/vhost-vsock-common.c
+++ b/hw/virtio/vhost-vsock-common.c
@@ -22,6 +22,7 @@
 const int feature_bits[] = {
     VIRTIO_VSOCK_F_SEQPACKET,
     VIRTIO_F_RING_RESET,
+    VIRTIO_F_RING_PACKED,
     VHOST_INVALID_FEATURE_BIT
 };
 
-- 
MST