summaryrefslogtreecommitdiff
path: root/drivers/char/virtio_console.c
diff options
context:
space:
mode:
authorMichael S. Tsirkin <mst@redhat.com>2018-04-20 20:24:23 +0300
committerMichael S. Tsirkin <mst@redhat.com>2018-04-25 20:41:16 +0300
commita7a69ec0d8e4a58be7db88d33cbfa2912807bb2b (patch)
tree01374a64530550c86ddf3bc55b55c9366dbdb62d /drivers/char/virtio_console.c
parent24a7e4d20783c0514850f24a5c41ede46ab058f0 (diff)
downloadlinux-a7a69ec0d8e4a58be7db88d33cbfa2912807bb2b.tar.xz
virtio_console: free buffers after reset
Console driver is out of spec. The spec says: A driver MUST NOT decrement the available idx on a live virtqueue (ie. there is no way to “unexpose” buffers). and it does exactly that by trying to detach unused buffers without doing a device reset first. Defer detaching the buffers until device unplug. Of course this means we might get an interrupt for a vq without an attached port now. Handle that by discarding the consumed buffer. Reported-by: Tiwei Bie <tiwei.bie@intel.com> Fixes: b3258ff1d6 ("virtio: Decrement avail idx on buffer detach") Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/char/virtio_console.c')
-rw-r--r--drivers/char/virtio_console.c49
1 files changed, 24 insertions, 25 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 3e56f328b4cb..26a66ffd943e 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1402,7 +1402,6 @@ static int add_port(struct ports_device *portdev, u32 id)
{
char debugfs_name[16];
struct port *port;
- struct port_buffer *buf;
dev_t devt;
unsigned int nr_added_bufs;
int err;
@@ -1513,8 +1512,6 @@ static int add_port(struct ports_device *portdev, u32 id)
return 0;
free_inbufs:
- while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
- free_buf(buf, true);
free_device:
device_destroy(pdrvdata.class, port->dev->devt);
free_cdev:
@@ -1539,34 +1536,14 @@ static void remove_port(struct kref *kref)
static void remove_port_data(struct port *port)
{
- struct port_buffer *buf;
-
spin_lock_irq(&port->inbuf_lock);
/* Remove unused data this port might have received. */
discard_port_data(port);
spin_unlock_irq(&port->inbuf_lock);
- /* Remove buffers we queued up for the Host to send us data in. */
- do {
- spin_lock_irq(&port->inbuf_lock);
- buf = virtqueue_detach_unused_buf(port->in_vq);
- spin_unlock_irq(&port->inbuf_lock);
- if (buf)
- free_buf(buf, true);
- } while (buf);
-
spin_lock_irq(&port->outvq_lock);
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
-
- /* Free pending buffers from the out-queue. */
- do {
- spin_lock_irq(&port->outvq_lock);
- buf = virtqueue_detach_unused_buf(port->out_vq);
- spin_unlock_irq(&port->outvq_lock);
- if (buf)
- free_buf(buf, true);
- } while (buf);
}
/*
@@ -1791,13 +1768,24 @@ static void control_work_handler(struct work_struct *work)
spin_unlock(&portdev->c_ivq_lock);
}
+static void flush_bufs(struct virtqueue *vq, bool can_sleep)
+{
+ struct port_buffer *buf;
+ unsigned int len;
+
+ while ((buf = virtqueue_get_buf(vq, &len)))
+ free_buf(buf, can_sleep);
+}
+
static void out_intr(struct virtqueue *vq)
{
struct port *port;
port = find_port_by_vq(vq->vdev->priv, vq);
- if (!port)
+ if (!port) {
+ flush_bufs(vq, false);
return;
+ }
wake_up_interruptible(&port->waitqueue);
}
@@ -1808,8 +1796,10 @@ static void in_intr(struct virtqueue *vq)
unsigned long flags;
port = find_port_by_vq(vq->vdev->priv, vq);
- if (!port)
+ if (!port) {
+ flush_bufs(vq, false);
return;
+ }
spin_lock_irqsave(&port->inbuf_lock, flags);
port->inbuf = get_inbuf(port);
@@ -1984,6 +1974,15 @@ static const struct file_operations portdev_fops = {
static void remove_vqs(struct ports_device *portdev)
{
+ struct virtqueue *vq;
+
+ virtio_device_for_each_vq(portdev->vdev, vq) {
+ struct port_buffer *buf;
+
+ flush_bufs(vq, true);
+ while ((buf = virtqueue_detach_unused_buf(vq)))
+ free_buf(buf, true);
+ }
portdev->vdev->config->del_vqs(portdev->vdev);
kfree(portdev->in_vqs);
kfree(portdev->out_vqs);