* [Qemu-devel] [PATCH] vhost-user-blk: start vhost when guest kicks
@ 2018-06-05 13:56 Yongji Xie
2018-06-05 14:23 ` Michael S. Tsirkin
0 siblings, 1 reply; 3+ messages in thread
From: Yongji Xie @ 2018-06-05 13:56 UTC (permalink / raw)
To: mst, stefanha, changpeng.liu; +Cc: qemu-devel, chaiwen, nixun, elohimes
Some old guests (before commit 7a11370e5: "virtio_blk: enable VQs early")
kick virtqueue before setting VIRTIO_CONFIG_S_DRIVER_OK. This would cause
that those old guests fail to boot with vhost-user-blk device.
To fix it, start vhost when guest kicks instead of waiting for .set_status().
Signed-off-by: Yongji Xie <xieyongji@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Ni Xun <nixun@baidu.com>
---
hw/block/vhost-user-blk.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index d755223..8fd0e6f 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -217,7 +217,27 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
+ VHostUserBlk *s = VHOST_USER_BLK(vdev);
+ int i;
+ if (s->dev.started) {
+ return;
+ }
+
+ /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
+ * vhost here instead of waiting for .set_status().
+ */
+ vhost_user_blk_start(vdev);
+
+ /* Kick right away to begin processing requests already in vring */
+ for (i = 0; i < s->dev.nvqs; i++) {
+ VirtQueue *kick_vq = virtio_get_queue(vdev, i);
+
+ if (!virtio_queue_get_desc_addr(vdev, i)) {
+ continue;
+ }
+ event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
+ }
}
static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] vhost-user-blk: start vhost when guest kicks
2018-06-05 13:56 [Qemu-devel] [PATCH] vhost-user-blk: start vhost when guest kicks Yongji Xie
@ 2018-06-05 14:23 ` Michael S. Tsirkin
2018-06-06 3:43 ` Yongji Xie
0 siblings, 1 reply; 3+ messages in thread
From: Michael S. Tsirkin @ 2018-06-05 14:23 UTC (permalink / raw)
To: Yongji Xie; +Cc: stefanha, changpeng.liu, qemu-devel, chaiwen, nixun
On Tue, Jun 05, 2018 at 09:56:10PM +0800, Yongji Xie wrote:
> Some old guests (before commit 7a11370e5: "virtio_blk: enable VQs early")
> kick virtqueue before setting VIRTIO_CONFIG_S_DRIVER_OK. This would cause
> that those old guests fail to boot with vhost-user-blk device.
>
> To fix it, start vhost when guest kicks instead of waiting for .set_status().
>
> Signed-off-by: Yongji Xie <xieyongji@baidu.com>
> Signed-off-by: Chai Wen <chaiwen@baidu.com>
> Signed-off-by: Ni Xun <nixun@baidu.com>
Can we at least limit this to when virtio 1.0 has not
been negotiated?
> ---
> hw/block/vhost-user-blk.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index d755223..8fd0e6f 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -217,7 +217,27 @@ static uint64_t vhost_user_blk_get_features(VirtIODevice *vdev,
>
> static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> {
> + VHostUserBlk *s = VHOST_USER_BLK(vdev);
> + int i;
>
> + if (s->dev.started) {
> + return;
> + }
> +
> + /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
> + * vhost here instead of waiting for .set_status().
> + */
> + vhost_user_blk_start(vdev);
> +
> + /* Kick right away to begin processing requests already in vring */
> + for (i = 0; i < s->dev.nvqs; i++) {
> + VirtQueue *kick_vq = virtio_get_queue(vdev, i);
> +
> + if (!virtio_queue_get_desc_addr(vdev, i)) {
> + continue;
> + }
> + event_notifier_set(virtio_queue_get_host_notifier(kick_vq));
> + }
> }
>
> static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
> --
> 1.7.9.5
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] vhost-user-blk: start vhost when guest kicks
2018-06-05 14:23 ` Michael S. Tsirkin
@ 2018-06-06 3:43 ` Yongji Xie
0 siblings, 0 replies; 3+ messages in thread
From: Yongji Xie @ 2018-06-06 3:43 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: stefanha, changpeng.liu, qemu-devel, chaiwen, nixun
On 5 June 2018 at 22:23, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Tue, Jun 05, 2018 at 09:56:10PM +0800, Yongji Xie wrote:
>> Some old guests (before commit 7a11370e5: "virtio_blk: enable VQs early")
>> kick virtqueue before setting VIRTIO_CONFIG_S_DRIVER_OK. This would cause
>> that those old guests fail to boot with vhost-user-blk device.
>>
>> To fix it, start vhost when guest kicks instead of waiting for .set_status().
>>
>> Signed-off-by: Yongji Xie <xieyongji@baidu.com>
>> Signed-off-by: Chai Wen <chaiwen@baidu.com>
>> Signed-off-by: Ni Xun <nixun@baidu.com>
>
> Can we at least limit this to when virtio 1.0 has not
> been negotiated?
>
OK, I will limit this to when driver is v0.9.x and device is v1.0 so
we don't violate the spec.
Thanks,
Yongji
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-06-06 3:43 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-06-05 13:56 [Qemu-devel] [PATCH] vhost-user-blk: start vhost when guest kicks Yongji Xie
2018-06-05 14:23 ` Michael S. Tsirkin
2018-06-06 3:43 ` Yongji Xie
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