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virtio-net: stop/start bh when appropriate

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Avoid sending out packets, and modifying
memory, when VM is stopped.
Add assert statements to verify this does not happen.

Avoid scheduling bh when vhost-net is started.

Stop bh when driver disabled bus mastering
(we must not access memory after this).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2010-11-22 19:52:30 +02:00
parent 9547732304
commit 783e770693
1 changed files with 50 additions and 16 deletions
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66
hw/virtio-net.c
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@ -99,9 +99,14 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
}
}
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
static bool virtio_net_started(VirtIONet *n, uint8_t status)
{
return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
(n->status & VIRTIO_NET_S_LINK_UP) && n->vm_running;
}
static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
{
VirtIONet *n = to_virtio_net(vdev);
if (!n->nic->nc.peer) {
return;
}
@ -112,9 +117,7 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
if (!tap_get_vhost_net(n->nic->nc.peer)) {
return;
}
if (!!n->vhost_started == ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
(n->status & VIRTIO_NET_S_LINK_UP) &&
n->vm_running)) {
if (!!n->vhost_started == virtio_net_started(n, status)) {
return;
}
if (!n->vhost_started) {
@ -131,6 +134,32 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
}
}
static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
{
VirtIONet *n = to_virtio_net(vdev);
virtio_net_vhost_status(n, status);
if (!n->tx_waiting) {
return;
}
if (virtio_net_started(n, status) && !n->vhost_started) {
if (n->tx_timer) {
qemu_mod_timer(n->tx_timer,
qemu_get_clock(vm_clock) + n->tx_timeout);
} else {
qemu_bh_schedule(n->tx_bh);
}
} else {
if (n->tx_timer) {
qemu_del_timer(n->tx_timer);
} else {
qemu_bh_cancel(n->tx_bh);
}
}
}
static void virtio_net_set_link_status(VLANClientState *nc)
{
VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
@ -675,11 +704,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
{
VirtQueueElement elem;
int32_t num_packets = 0;
if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return num_packets;
}
assert(n->vm_running);
if (n->async_tx.elem.out_num) {
virtio_queue_set_notification(n->tx_vq, 0);
return num_packets;
@ -738,6 +768,12 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIONet *n = to_virtio_net(vdev);
/* This happens when device was stopped but VCPU wasn't. */
if (!n->vm_running) {
n->tx_waiting = 1;
return;
}
if (n->tx_waiting) {
virtio_queue_set_notification(vq, 1);
qemu_del_timer(n->tx_timer);
@ -758,14 +794,19 @@ static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
if (unlikely(n->tx_waiting)) {
return;
}
n->tx_waiting = 1;
/* This happens when device was stopped but VCPU wasn't. */
if (!n->vm_running) {
return;
}
virtio_queue_set_notification(vq, 0);
qemu_bh_schedule(n->tx_bh);
n->tx_waiting = 1;
}
static void virtio_net_tx_timer(void *opaque)
{
VirtIONet *n = opaque;
assert(n->vm_running);
n->tx_waiting = 0;
@ -782,6 +823,8 @@ static void virtio_net_tx_bh(void *opaque)
VirtIONet *n = opaque;
int32_t ret;
assert(n->vm_running);
n->tx_waiting = 0;
/* Just in case the driver is not ready on more */
@ -926,15 +969,6 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
}
}
n->mac_table.first_multi = i;
if (n->tx_waiting) {
if (n->tx_timer) {
qemu_mod_timer(n->tx_timer,
qemu_get_clock(vm_clock) + n->tx_timeout);
} else {
qemu_bh_schedule(n->tx_bh);
}
}
return 0;
}