| Message ID | 20220524154056.2896913-3-alex.bennee@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-gpio and various virtio cleanups | expand |
On Tue, May 24, 2022 at 04:40:43PM +0100, Alex Bennée wrote: > When debugging a new vhost user you may be surprised to see > VHOST_USER_F_PROTOCOL getting squashed in the maze of > backend_features, acked_features and guest_features. Expand the > description here to help the next poor soul trying to work through > this. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > include/hw/virtio/virtio.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index db1c0ddf6b..2b2587d324 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -24,7 +24,12 @@ > #include "qom/object.h" > #include "hw/virtio/vhost.h" > > -/* A guest should never accept this. It implies negotiation is broken. */ > +/* > + * A guest should never accept this. It implies negotiation is > + * broken between the driver frontend and the device. This bit is > + * re-used for vhost to advertise VHOST_USER_F_PROTOCOL_FEATURES s/vhost/vhost-user/ > + * between QEMU and a vhost backend. > + */ > #define VIRTIO_F_BAD_FEATURE 30 > > #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \ > -- > 2.30.2 >
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index db1c0ddf6b..2b2587d324 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -24,7 +24,12 @@ #include "qom/object.h" #include "hw/virtio/vhost.h" -/* A guest should never accept this. It implies negotiation is broken. */ +/* + * A guest should never accept this. It implies negotiation is + * broken between the driver frontend and the device. This bit is + * re-used for vhost to advertise VHOST_USER_F_PROTOCOL_FEATURES + * between QEMU and a vhost backend. + */ #define VIRTIO_F_BAD_FEATURE 30 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \
When debugging a new vhost user you may be surprised to see VHOST_USER_F_PROTOCOL getting squashed in the maze of backend_features, acked_features and guest_features. Expand the description here to help the next poor soul trying to work through this. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- include/hw/virtio/virtio.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)