| Message ID | 20191010180412.26236-1-mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,1/2] virtio: new post_load hook | expand |
Michael S. Tsirkin <mst@redhat.com> writes: > Post load hook in virtio vmsd is called early while device is processed, > and when VirtIODevice core isn't fully initialized. Most device > specific code isn't ready to deal with a device in such state, and > behaves weirdly. > > Add a new post_load hook in a device class instead. Devices should use > this unless they specifically want to verify the migration stream as > it's processed, e.g. for bounds checking. > > Suggested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > Cc: Mikhail Sennikovsky <mikhail.sennikovskii@cloud.ionos.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > hw/virtio/virtio.c | 7 +++++++ > include/hw/virtio/virtio.h | 6 ++++++ > 2 files changed, 13 insertions(+) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 527df03bfd..54a46e204c 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -2291,6 +2291,13 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) > } > rcu_read_unlock(); > > + if (vdc->post_load) { > + ret = vdc->post_load(vdev); > + if (ret) { > + return ret; > + } I see this pattern repeated above because we get early exits on error but here it seems superfluous. Why not: return vdc->_post_load(vdev) ? > + } > + > return 0; > } > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 48e8d04ff6..ca4f9c0bcc 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -158,6 +158,12 @@ typedef struct VirtioDeviceClass { > */ > void (*save)(VirtIODevice *vdev, QEMUFile *f); > int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); > + /* Post load hook in vmsd is called early while device is processed, and > + * when VirtIODevice isn't fully initialized. Devices should use this instead, > + * unless they specifically want to verify the migration stream as it's > + * processed, e.g. for bounds checking. > + */ > + int (*post_load)(VirtIODevice *vdev); > const VMStateDescription *vmsd; > } VirtioDeviceClass; -- Alex Bennée
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 527df03bfd..54a46e204c 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2291,6 +2291,13 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } rcu_read_unlock(); + if (vdc->post_load) { + ret = vdc->post_load(vdev); + if (ret) { + return ret; + } + } + return 0; } diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 48e8d04ff6..ca4f9c0bcc 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -158,6 +158,12 @@ typedef struct VirtioDeviceClass { */ void (*save)(VirtIODevice *vdev, QEMUFile *f); int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); + /* Post load hook in vmsd is called early while device is processed, and + * when VirtIODevice isn't fully initialized. Devices should use this instead, + * unless they specifically want to verify the migration stream as it's + * processed, e.g. for bounds checking. + */ + int (*post_load)(VirtIODevice *vdev); const VMStateDescription *vmsd; } VirtioDeviceClass;
Post load hook in virtio vmsd is called early while device is processed, and when VirtIODevice core isn't fully initialized. Most device specific code isn't ready to deal with a device in such state, and behaves weirdly. Add a new post_load hook in a device class instead. Devices should use this unless they specifically want to verify the migration stream as it's processed, e.g. for bounds checking. Suggested-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mikhail Sennikovsky <mikhail.sennikovskii@cloud.ionos.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- hw/virtio/virtio.c | 7 +++++++ include/hw/virtio/virtio.h | 6 ++++++ 2 files changed, 13 insertions(+)