* [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue
@ 2015-07-15 8:20 Wen Congyang
2015-07-15 8:42 ` Jason Wang
0 siblings, 1 reply; 5+ messages in thread
From: Wen Congyang @ 2015-07-15 8:20 UTC (permalink / raw)
To: qemu-devl, Jason Wang, Michael S. Tsirkin; +Cc: Fam Zheng, Stefan Hajnoczi
commit da51a335 adds all queues in .realize(). But if the
guest doesn't support multiqueue, we forget to remove them. And
we cannot handle the ctrl vq corretly. The guest will hang.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
hw/net/virtio-net.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 78 insertions(+), 15 deletions(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index e3c2db3..48c7705 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1306,9 +1306,86 @@ static void virtio_net_tx_bh(void *opaque)
}
}
+static void virtio_net_add_queue(VirtIONet *n, int index)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(n);
+
+ n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
+ if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
+ n->vqs[index].tx_vq =
+ virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
+ n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+ virtio_net_tx_timer,
+ &n->vqs[index]);
+ } else {
+ n->vqs[index].tx_vq =
+ virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
+ n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
+ }
+
+ n->vqs[index].tx_waiting = 0;
+ n->vqs[index].n = n;
+}
+
+static void virtio_net_del_queue(VirtIONet *n, int index)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(n);
+ VirtIONetQueue *q = &n->vqs[index];
+ NetClientState *nc = qemu_get_subqueue(n->nic, index);
+
+ qemu_purge_queued_packets(nc);
+
+ virtio_del_queue(vdev, index * 2);
+ if (q->tx_timer) {
+ timer_del(q->tx_timer);
+ timer_free(q->tx_timer);
+ } else {
+ qemu_bh_delete(q->tx_bh);
+ }
+ virtio_del_queue(vdev, index * 2 + 1);
+}
+
+static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(n);
+ int old_num_queues = virtio_get_num_queues(vdev);
+ int new_num_queues = new_max_queues * 2 + 1;
+ int i;
+
+ assert(old_num_queues >= 3);
+ assert(old_num_queues % 2 == 1);
+
+ if (old_num_queues == new_num_queues) {
+ return;
+ }
+
+ /*
+ * We always need to remove and add ctrl vq if
+ * old_num_queues != new_num_queues. Remove ctrl_vq first,
+ * and then we only enter one of the following too loops.
+ */
+ virtio_del_queue(vdev, old_num_queues - 1);
+
+ for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
+ /* new_num_queues < old_num_queues */
+ virtio_net_del_queue(n, i / 2);
+ }
+
+ for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
+ /* new_num_queues > old_num_queues */
+ virtio_net_add_queue(n, i / 2);
+ }
+
+ /* add ctrl_vq last */
+ n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
+}
+
static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
{
+ int max = multiqueue ? n->max_queues : 1;
+
n->multiqueue = multiqueue;
+ virtio_net_change_num_queues(n, max);
virtio_net_set_queues(n);
}
@@ -1583,21 +1660,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
}
for (i = 0; i < n->max_queues; i++) {
- n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
- if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
- n->vqs[i].tx_vq =
- virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
- n->vqs[i].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
- virtio_net_tx_timer,
- &n->vqs[i]);
- } else {
- n->vqs[i].tx_vq =
- virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
- n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
- }
-
- n->vqs[i].tx_waiting = 0;
- n->vqs[i].n = n;
+ virtio_net_add_queue(n, i);
}
n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
--
2.4.3
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue
2015-07-15 8:20 [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue Wen Congyang
@ 2015-07-15 8:42 ` Jason Wang
2015-07-15 8:56 ` Wen Congyang
2015-07-15 9:04 ` Wen Congyang
0 siblings, 2 replies; 5+ messages in thread
From: Jason Wang @ 2015-07-15 8:42 UTC (permalink / raw)
To: Wen Congyang, qemu-devl, Michael S. Tsirkin; +Cc: Fam Zheng, Stefan Hajnoczi
On 07/15/2015 04:20 PM, Wen Congyang wrote:
> commit da51a335 adds all queues in .realize(). But if the
> guest doesn't support multiqueue, we forget to remove them. And
> we cannot handle the ctrl vq corretly. The guest will hang.
>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> ---
> hw/net/virtio-net.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 78 insertions(+), 15 deletions(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index e3c2db3..48c7705 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -1306,9 +1306,86 @@ static void virtio_net_tx_bh(void *opaque)
> }
> }
>
> +static void virtio_net_add_queue(VirtIONet *n, int index)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
> +
> + n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
> + if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
> + n->vqs[index].tx_vq =
> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
> + n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> + virtio_net_tx_timer,
> + &n->vqs[index]);
> + } else {
> + n->vqs[index].tx_vq =
> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
> + n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
> + }
> +
> + n->vqs[index].tx_waiting = 0;
> + n->vqs[index].n = n;
> +}
> +
> +static void virtio_net_del_queue(VirtIONet *n, int index)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
> + VirtIONetQueue *q = &n->vqs[index];
> + NetClientState *nc = qemu_get_subqueue(n->nic, index);
> +
> + qemu_purge_queued_packets(nc);
> +
> + virtio_del_queue(vdev, index * 2);
> + if (q->tx_timer) {
> + timer_del(q->tx_timer);
> + timer_free(q->tx_timer);
> + } else {
> + qemu_bh_delete(q->tx_bh);
> + }
> + virtio_del_queue(vdev, index * 2 + 1);
> +}
Ok, then in unrealize() you may just want to delete bhs/timers up to
curr_queues. Otherwise it may cause a use after free?
> +
> +static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
> +{
> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
> + int old_num_queues = virtio_get_num_queues(vdev);
> + int new_num_queues = new_max_queues * 2 + 1;
> + int i;
> +
> + assert(old_num_queues >= 3);
> + assert(old_num_queues % 2 == 1);
> +
> + if (old_num_queues == new_num_queues) {
> + return;
> + }
> +
> + /*
> + * We always need to remove and add ctrl vq if
> + * old_num_queues != new_num_queues. Remove ctrl_vq first,
> + * and then we only enter one of the following too loops.
> + */
> + virtio_del_queue(vdev, old_num_queues - 1);
> +
> + for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
> + /* new_num_queues < old_num_queues */
> + virtio_net_del_queue(n, i / 2);
> + }
> +
> + for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
> + /* new_num_queues > old_num_queues */
> + virtio_net_add_queue(n, i / 2);
> + }
> +
> + /* add ctrl_vq last */
> + n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
> +}
> +
> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
> {
> + int max = multiqueue ? n->max_queues : 1;
> +
> n->multiqueue = multiqueue;
> + virtio_net_change_num_queues(n, max);
>
> virtio_net_set_queues(n);
> }
> @@ -1583,21 +1660,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
> }
>
> for (i = 0; i < n->max_queues; i++) {
> - n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
> - if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
> - n->vqs[i].tx_vq =
> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
> - n->vqs[i].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> - virtio_net_tx_timer,
> - &n->vqs[i]);
> - } else {
> - n->vqs[i].tx_vq =
> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
> - n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
> - }
> -
> - n->vqs[i].tx_waiting = 0;
> - n->vqs[i].n = n;
> + virtio_net_add_queue(n, i);
> }
>
> n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue
2015-07-15 8:42 ` Jason Wang
@ 2015-07-15 8:56 ` Wen Congyang
2015-07-15 9:04 ` Wen Congyang
1 sibling, 0 replies; 5+ messages in thread
From: Wen Congyang @ 2015-07-15 8:56 UTC (permalink / raw)
To: Jason Wang, qemu-devl, Michael S. Tsirkin; +Cc: Fam Zheng, Stefan Hajnoczi
On 07/15/2015 04:42 PM, Jason Wang wrote:
>
>
> On 07/15/2015 04:20 PM, Wen Congyang wrote:
>> commit da51a335 adds all queues in .realize(). But if the
>> guest doesn't support multiqueue, we forget to remove them. And
>> we cannot handle the ctrl vq corretly. The guest will hang.
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>> hw/net/virtio-net.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---------
>> 1 file changed, 78 insertions(+), 15 deletions(-)
>>
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index e3c2db3..48c7705 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -1306,9 +1306,86 @@ static void virtio_net_tx_bh(void *opaque)
>> }
>> }
>>
>> +static void virtio_net_add_queue(VirtIONet *n, int index)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> +
>> + n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>> + if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
>> + n->vqs[index].tx_vq =
>> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
>> + n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>> + virtio_net_tx_timer,
>> + &n->vqs[index]);
>> + } else {
>> + n->vqs[index].tx_vq =
>> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
>> + n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
>> + }
>> +
>> + n->vqs[index].tx_waiting = 0;
>> + n->vqs[index].n = n;
>> +}
>> +
>> +static void virtio_net_del_queue(VirtIONet *n, int index)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> + VirtIONetQueue *q = &n->vqs[index];
>> + NetClientState *nc = qemu_get_subqueue(n->nic, index);
>> +
>> + qemu_purge_queued_packets(nc);
>> +
>> + virtio_del_queue(vdev, index * 2);
>> + if (q->tx_timer) {
>> + timer_del(q->tx_timer);
>> + timer_free(q->tx_timer);
>> + } else {
>> + qemu_bh_delete(q->tx_bh);
>> + }
>> + virtio_del_queue(vdev, index * 2 + 1);
>> +}
>
> Ok, then in unrealize() you may just want to delete bhs/timers up to
> curr_queues. Otherwise it may cause a use after free?
Yes. curr_queues is set in virtio_net_handle_mq(). It may be less than
max_queues. So I think we cannot use curr_queues directly. If mutliqueue
is enabled, we should delete bhs/timers up to max_queues, otherwise, up to 1.
Thanks
Wen Congyang
>
>> +
>> +static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> + int old_num_queues = virtio_get_num_queues(vdev);
>> + int new_num_queues = new_max_queues * 2 + 1;
>> + int i;
>> +
>> + assert(old_num_queues >= 3);
>> + assert(old_num_queues % 2 == 1);
>> +
>> + if (old_num_queues == new_num_queues) {
>> + return;
>> + }
>> +
>> + /*
>> + * We always need to remove and add ctrl vq if
>> + * old_num_queues != new_num_queues. Remove ctrl_vq first,
>> + * and then we only enter one of the following too loops.
>> + */
>> + virtio_del_queue(vdev, old_num_queues - 1);
>> +
>> + for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
>> + /* new_num_queues < old_num_queues */
>> + virtio_net_del_queue(n, i / 2);
>> + }
>> +
>> + for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
>> + /* new_num_queues > old_num_queues */
>> + virtio_net_add_queue(n, i / 2);
>> + }
>> +
>> + /* add ctrl_vq last */
>> + n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
>> +}
>> +
>> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
>> {
>> + int max = multiqueue ? n->max_queues : 1;
>> +
>> n->multiqueue = multiqueue;
>> + virtio_net_change_num_queues(n, max);
>>
>> virtio_net_set_queues(n);
>> }
>> @@ -1583,21 +1660,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
>> }
>>
>> for (i = 0; i < n->max_queues; i++) {
>> - n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>> - if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
>> - n->vqs[i].tx_vq =
>> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
>> - n->vqs[i].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>> - virtio_net_tx_timer,
>> - &n->vqs[i]);
>> - } else {
>> - n->vqs[i].tx_vq =
>> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
>> - n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
>> - }
>> -
>> - n->vqs[i].tx_waiting = 0;
>> - n->vqs[i].n = n;
>> + virtio_net_add_queue(n, i);
>> }
>>
>> n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
>
> .
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue
2015-07-15 8:42 ` Jason Wang
2015-07-15 8:56 ` Wen Congyang
@ 2015-07-15 9:04 ` Wen Congyang
2015-07-15 9:05 ` Jason Wang
1 sibling, 1 reply; 5+ messages in thread
From: Wen Congyang @ 2015-07-15 9:04 UTC (permalink / raw)
To: Jason Wang, qemu-devl, Michael S. Tsirkin; +Cc: Fam Zheng, Stefan Hajnoczi
On 07/15/2015 04:42 PM, Jason Wang wrote:
>
>
> On 07/15/2015 04:20 PM, Wen Congyang wrote:
>> commit da51a335 adds all queues in .realize(). But if the
>> guest doesn't support multiqueue, we forget to remove them. And
>> we cannot handle the ctrl vq corretly. The guest will hang.
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>> hw/net/virtio-net.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---------
>> 1 file changed, 78 insertions(+), 15 deletions(-)
>>
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index e3c2db3..48c7705 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -1306,9 +1306,86 @@ static void virtio_net_tx_bh(void *opaque)
>> }
>> }
>>
>> +static void virtio_net_add_queue(VirtIONet *n, int index)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> +
>> + n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>> + if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
>> + n->vqs[index].tx_vq =
>> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
>> + n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>> + virtio_net_tx_timer,
>> + &n->vqs[index]);
>> + } else {
>> + n->vqs[index].tx_vq =
>> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
>> + n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
>> + }
>> +
>> + n->vqs[index].tx_waiting = 0;
>> + n->vqs[index].n = n;
>> +}
>> +
>> +static void virtio_net_del_queue(VirtIONet *n, int index)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> + VirtIONetQueue *q = &n->vqs[index];
>> + NetClientState *nc = qemu_get_subqueue(n->nic, index);
>> +
>> + qemu_purge_queued_packets(nc);
>> +
>> + virtio_del_queue(vdev, index * 2);
>> + if (q->tx_timer) {
>> + timer_del(q->tx_timer);
>> + timer_free(q->tx_timer);
>> + } else {
>> + qemu_bh_delete(q->tx_bh);
>> + }
>> + virtio_del_queue(vdev, index * 2 + 1);
>> +}
>
> Ok, then in unrealize() you may just want to delete bhs/timers up to
> curr_queues. Otherwise it may cause a use after free?
One question: If the max_queues in qemu is 3, and the guest set queues to 2.
which vq is ctrl vq? vq[4] or vq[6]?
Thanks
Wen Congyang
>
>> +
>> +static void virtio_net_change_num_queues(VirtIONet *n, int new_max_queues)
>> +{
>> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>> + int old_num_queues = virtio_get_num_queues(vdev);
>> + int new_num_queues = new_max_queues * 2 + 1;
>> + int i;
>> +
>> + assert(old_num_queues >= 3);
>> + assert(old_num_queues % 2 == 1);
>> +
>> + if (old_num_queues == new_num_queues) {
>> + return;
>> + }
>> +
>> + /*
>> + * We always need to remove and add ctrl vq if
>> + * old_num_queues != new_num_queues. Remove ctrl_vq first,
>> + * and then we only enter one of the following too loops.
>> + */
>> + virtio_del_queue(vdev, old_num_queues - 1);
>> +
>> + for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
>> + /* new_num_queues < old_num_queues */
>> + virtio_net_del_queue(n, i / 2);
>> + }
>> +
>> + for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
>> + /* new_num_queues > old_num_queues */
>> + virtio_net_add_queue(n, i / 2);
>> + }
>> +
>> + /* add ctrl_vq last */
>> + n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
>> +}
>> +
>> static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
>> {
>> + int max = multiqueue ? n->max_queues : 1;
>> +
>> n->multiqueue = multiqueue;
>> + virtio_net_change_num_queues(n, max);
>>
>> virtio_net_set_queues(n);
>> }
>> @@ -1583,21 +1660,7 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
>> }
>>
>> for (i = 0; i < n->max_queues; i++) {
>> - n->vqs[i].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>> - if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
>> - n->vqs[i].tx_vq =
>> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
>> - n->vqs[i].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>> - virtio_net_tx_timer,
>> - &n->vqs[i]);
>> - } else {
>> - n->vqs[i].tx_vq =
>> - virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
>> - n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
>> - }
>> -
>> - n->vqs[i].tx_waiting = 0;
>> - n->vqs[i].n = n;
>> + virtio_net_add_queue(n, i);
>> }
>>
>> n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
>
> .
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue
2015-07-15 9:04 ` Wen Congyang
@ 2015-07-15 9:05 ` Jason Wang
0 siblings, 0 replies; 5+ messages in thread
From: Jason Wang @ 2015-07-15 9:05 UTC (permalink / raw)
To: Wen Congyang, qemu-devl, Michael S. Tsirkin; +Cc: Fam Zheng, Stefan Hajnoczi
On 07/15/2015 05:04 PM, Wen Congyang wrote:
> On 07/15/2015 04:42 PM, Jason Wang wrote:
>> >
>> >
>> > On 07/15/2015 04:20 PM, Wen Congyang wrote:
>>> >> commit da51a335 adds all queues in .realize(). But if the
>>> >> guest doesn't support multiqueue, we forget to remove them. And
>>> >> we cannot handle the ctrl vq corretly. The guest will hang.
>>> >>
>>> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>> >> ---
>>> >> hw/net/virtio-net.c | 93 ++++++++++++++++++++++++++++++++++++++++++++---------
>>> >> 1 file changed, 78 insertions(+), 15 deletions(-)
>>> >>
>>> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>>> >> index e3c2db3..48c7705 100644
>>> >> --- a/hw/net/virtio-net.c
>>> >> +++ b/hw/net/virtio-net.c
>>> >> @@ -1306,9 +1306,86 @@ static void virtio_net_tx_bh(void *opaque)
>>> >> }
>>> >> }
>>> >>
>>> >> +static void virtio_net_add_queue(VirtIONet *n, int index)
>>> >> +{
>>> >> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>> >> +
>>> >> + n->vqs[index].rx_vq = virtio_add_queue(vdev, 256, virtio_net_handle_rx);
>>> >> + if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
>>> >> + n->vqs[index].tx_vq =
>>> >> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_timer);
>>> >> + n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
>>> >> + virtio_net_tx_timer,
>>> >> + &n->vqs[index]);
>>> >> + } else {
>>> >> + n->vqs[index].tx_vq =
>>> >> + virtio_add_queue(vdev, 256, virtio_net_handle_tx_bh);
>>> >> + n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
>>> >> + }
>>> >> +
>>> >> + n->vqs[index].tx_waiting = 0;
>>> >> + n->vqs[index].n = n;
>>> >> +}
>>> >> +
>>> >> +static void virtio_net_del_queue(VirtIONet *n, int index)
>>> >> +{
>>> >> + VirtIODevice *vdev = VIRTIO_DEVICE(n);
>>> >> + VirtIONetQueue *q = &n->vqs[index];
>>> >> + NetClientState *nc = qemu_get_subqueue(n->nic, index);
>>> >> +
>>> >> + qemu_purge_queued_packets(nc);
>>> >> +
>>> >> + virtio_del_queue(vdev, index * 2);
>>> >> + if (q->tx_timer) {
>>> >> + timer_del(q->tx_timer);
>>> >> + timer_free(q->tx_timer);
>>> >> + } else {
>>> >> + qemu_bh_delete(q->tx_bh);
>>> >> + }
>>> >> + virtio_del_queue(vdev, index * 2 + 1);
>>> >> +}
>> >
>> > Ok, then in unrealize() you may just want to delete bhs/timers up to
>> > curr_queues. Otherwise it may cause a use after free?
> One question: If the max_queues in qemu is 3, and the guest set queues to 2.
> which vq is ctrl vq? vq[4] or vq[6]?
Spec (5.1.2) said
"
0
receiveq1
1
transmitq1
…
2N
receiveqN
2N+1
transmitqN
2N+2
controlq
N=1 if VIRTIO_NET_F_MQ is not negotiated, otherwise N is set by
max_virtqueue_pairs.
"
So should be 6.
> Thanks
> Wen Congyang
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-07-15 9:05 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-07-15 8:20 [Qemu-devel] [PATCH v2 for-2.4] virtio-net: remove virtio queues if the guest doesn't support multiqueue Wen Congyang
2015-07-15 8:42 ` Jason Wang
2015-07-15 8:56 ` Wen Congyang
2015-07-15 9:04 ` Wen Congyang
2015-07-15 9:05 ` Jason Wang
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