From 5b1bf7cb673ade0ab5c75f200dce911d9fb91c21 Mon Sep 17 00:00:00 2001 From: Heinz Graalfs Date: Tue, 29 Oct 2013 09:39:48 +1030 Subject: [PATCH] virtio_ring: let virtqueue_{kick()/notify()} return a bool virtqueue_{kick()/notify()} should exploit the new host notification API. If the notify call returned with a negative value the host kick failed (e.g. a kick triggered after a device was hot-unplugged). In this case the virtqueue is set to 'broken' and false is returned, otherwise true. Signed-off-by: Heinz Graalfs Signed-off-by: Rusty Russell --- drivers/virtio/virtio_ring.c | 20 ++++++++++++++++---- include/linux/virtio.h | 4 ++-- 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 97dd51619b55..b47142723119 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -430,13 +430,22 @@ EXPORT_SYMBOL_GPL(virtqueue_kick_prepare); * @vq: the struct virtqueue * * This does not need to be serialized. + * + * Returns false if host notify failed or queue is broken, otherwise true. */ -void virtqueue_notify(struct virtqueue *_vq) +bool virtqueue_notify(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); + if (unlikely(vq->broken)) + return false; + /* Prod other side to tell it about changes. */ - vq->notify(_vq); + if (vq->notify(_vq) < 0) { + vq->broken = true; + return false; + } + return true; } EXPORT_SYMBOL_GPL(virtqueue_notify); @@ -449,11 +458,14 @@ EXPORT_SYMBOL_GPL(virtqueue_notify); * * Caller must ensure we don't call this with other virtqueue * operations at the same time (except where noted). + * + * Returns false if kick failed, otherwise true. */ -void virtqueue_kick(struct virtqueue *vq) +bool virtqueue_kick(struct virtqueue *vq) { if (virtqueue_kick_prepare(vq)) - virtqueue_notify(vq); + return virtqueue_notify(vq); + return true; } EXPORT_SYMBOL_GPL(virtqueue_kick); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 36d36cc89329..9b4de15fcb2f 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -51,11 +51,11 @@ int virtqueue_add_sgs(struct virtqueue *vq, void *data, gfp_t gfp); -void virtqueue_kick(struct virtqueue *vq); +bool virtqueue_kick(struct virtqueue *vq); bool virtqueue_kick_prepare(struct virtqueue *vq); -void virtqueue_notify(struct virtqueue *vq); +bool virtqueue_notify(struct virtqueue *vq); void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);