From 2640d2a5ff08978d67bd87518d05d6b499488c9a Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Mon, 19 Sep 2016 14:28:03 +0100 Subject: virtio: add virtio_detach_element() During device reset or similar situations a VirtQueueElement needs to be freed without pushing it onto the used ring or rewinding the virtqueue. Extract a new function to do this. Later patches add virtio_detach_element() calls to existing device so that scatter-gather lists are unmapped and vq->inuse goes back to zero during device reset. Currently some devices don't bother and simply call g_free(elem) which is not a clean way to throw away a VirtQueueElement. Signed-off-by: Stefan Hajnoczi Acked-by: Greg Kurz Reviewed-by: Ladi Prosek Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'hw/virtio/virtio.c') diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 18ce333457..46f79c9e14 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -264,12 +264,35 @@ static void virtqueue_unmap_sg(VirtQueue *vq, const VirtQueueElement *elem, 0, elem->out_sg[i].iov_len); } +/* virtqueue_detach_element: + * @vq: The #VirtQueue + * @elem: The #VirtQueueElement + * @len: number of bytes written + * + * Detach the element from the virtqueue. This function is suitable for device + * reset or other situations where a #VirtQueueElement is simply freed and will + * not be pushed or discarded. + */ +void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, + unsigned int len) +{ + vq->inuse--; + virtqueue_unmap_sg(vq, elem, len); +} + +/* virtqueue_discard: + * @vq: The #VirtQueue + * @elem: The #VirtQueueElement + * @len: number of bytes written + * + * Pretend the most recent element wasn't popped from the virtqueue. The next + * call to virtqueue_pop() will refetch the element. + */ void virtqueue_discard(VirtQueue *vq, const VirtQueueElement *elem, unsigned int len) { vq->last_avail_idx--; - vq->inuse--; - virtqueue_unmap_sg(vq, elem, len); + virtqueue_detach_element(vq, elem, len); } /* virtqueue_rewind: -- cgit v1.2.3 From 1a665855d7144bb3df382630a2b5e4039e95e466 Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Thu, 6 Oct 2016 14:55:39 +0200 Subject: virtio: prepare change VMSTATE_VIRTIO_DEVICE macro In most cases the functions passed to VMSTATE_VIRTIO_DEVICE only call the virtio_load and virtio_save wrappers. Some include some pre- and post- massaging too. The massaging is better expressed as such in the VMStateDescription. Let us prepare for changing the semantic of the VMSTATE_VIRTIO_DEVICE macro so that it is more similar to the other VMSTATE_*_DEVICE macros in a sense that it is a field definition. The preprocessor conditionals are going to be removed as soon as every usage is converted to the new semantic. Signed-off-by: Halil Pasic Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'hw/virtio/virtio.c') diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 46f79c9e14..62b9c002ff 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1645,6 +1645,27 @@ void virtio_vmstate_save(QEMUFile *f, void *opaque, size_t size) virtio_save(VIRTIO_DEVICE(opaque), f); } +/* A wrapper for use as a VMState .put function */ +static void virtio_device_put(QEMUFile *f, void *opaque, size_t size) +{ + virtio_save(VIRTIO_DEVICE(opaque), f); +} + +/* A wrapper for use as a VMState .get function */ +static int virtio_device_get(QEMUFile *f, void *opaque, size_t size) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + DeviceClass *dc = DEVICE_CLASS(VIRTIO_DEVICE_GET_CLASS(vdev)); + + return virtio_load(vdev, f, dc->vmsd->version_id); +} + +const VMStateInfo virtio_vmstate_info = { + .name = "virtio", + .get = virtio_device_get, + .put = virtio_device_put, +}; + static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) { VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); -- cgit v1.2.3 From 5705653ff8666ffb247971361904f902aa033351 Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Thu, 6 Oct 2016 14:55:50 +0200 Subject: virtio: cleanup VMSTATE_VIRTIO_DEVICE Now all the usages of the old version of VMSTATE_VIRTIO_DEVICE are gone, so we can get rid of the conditionals, and the old macro. Signed-off-by: Halil Pasic Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'hw/virtio/virtio.c') diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 62b9c002ff..d48d1a98a7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1639,12 +1639,6 @@ void virtio_save(VirtIODevice *vdev, QEMUFile *f) vmstate_save_state(f, &vmstate_virtio, vdev, NULL); } -/* A wrapper for use as a VMState .put function */ -void virtio_vmstate_save(QEMUFile *f, void *opaque, size_t size) -{ - virtio_save(VIRTIO_DEVICE(opaque), f); -} - /* A wrapper for use as a VMState .put function */ static void virtio_device_put(QEMUFile *f, void *opaque, size_t size) { -- cgit v1.2.3