Re: [PATCH v4 2/2] vhost-user-blk: delay vhost_user_blk_disconnect
On Sat, May 30, 2020 at 08:55:30PM -0400, Raphael Norwitz wrote:
> On Thu, May 28, 2020 at 5:13 AM Dima Stepanov wrote:
> >
> > A socket write during vhost-user communication may trigger a disconnect
> > event, calling vhost_user_blk_disconnect() and clearing all the
> > vhost_dev structures holding data that vhost-user functions expect to
> > remain valid to roll back initialization correctly. Delay the cleanup to
> > keep vhost_dev structure valid.
> > There are two possible states to handle:
> > 1. RUN_STATE_PRELAUNCH: skip bh oneshot call and perform disconnect in
> > the caller routine.
> > 2. RUN_STATE_RUNNING: delay by using bh
> >
> > BH changes are based on the similar changes for the vhost-user-net
> > device:
> > commit e7c83a885f865128ae3cf1946f8cb538b63cbfba
> > "vhost-user: delay vhost_user_stop"
> >
> > Signed-off-by: Dima Stepanov
>
> Reviewed-by: Raphael Norwitz
>
> Li Feng - would you also like to sign off here?
Raphael,
Will you take this patchset for merging or what is the next step? )
Thanks, Dima.
>
> > ---
> > hw/block/vhost-user-blk.c | 38 +-
> > 1 file changed, 37 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> > index 9d8c0b3..76838e7 100644
> > --- a/hw/block/vhost-user-blk.c
> > +++ b/hw/block/vhost-user-blk.c
> > @@ -349,6 +349,19 @@ static void vhost_user_blk_disconnect(DeviceState *dev)
> > vhost_dev_cleanup(>dev);
> > }
> >
> > +static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
> > +
> > +static void vhost_user_blk_chr_closed_bh(void *opaque)
> > +{
> > +DeviceState *dev = opaque;
> > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > +VHostUserBlk *s = VHOST_USER_BLK(vdev);
> > +
> > +vhost_user_blk_disconnect(dev);
> > +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, vhost_user_blk_event,
> > +NULL, opaque, NULL, true);
> > +}
> > +
> > static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
> > {
> > DeviceState *dev = opaque;
> > @@ -363,7 +376,30 @@ static void vhost_user_blk_event(void *opaque,
> > QEMUChrEvent event)
> > }
> > break;
> > case CHR_EVENT_CLOSED:
> > -vhost_user_blk_disconnect(dev);
> > +/*
> > + * A close event may happen during a read/write, but vhost
> > + * code assumes the vhost_dev remains setup, so delay the
> > + * stop & clear. There are two possible paths to hit this
> > + * disconnect event:
> > + * 1. When VM is in the RUN_STATE_PRELAUNCH state. The
> > + * vhost_user_blk_device_realize() is a caller.
> > + * 2. In tha main loop phase after VM start.
> > + *
> > + * For p2 the disconnect event will be delayed. We can't
> > + * do the same for p1, because we are not running the loop
> > + * at this moment. So just skip this step and perform
> > + * disconnect in the caller function.
> > + *
> > + * TODO: maybe it is a good idea to make the same fix
> > + * for other vhost-user devices.
> > + */
> > +if (runstate_is_running()) {
> > +AioContext *ctx = qemu_get_current_aio_context();
> > +
> > +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, NULL, NULL,
> > +NULL, NULL, false);
> > +aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh,
> > opaque);
> > +}
> > break;
> > case CHR_EVENT_BREAK:
> > case CHR_EVENT_MUX_IN:
> > --
> > 2.7.4
> >
> >
Re: [PATCH v4 2/2] vhost-user-blk: delay vhost_user_blk_disconnect
Hi Raphael,
I'm sorry. I just end my journey today.
Yes, pls sign off me here.
this patch is nearly the same as my previous patch.
Thanks,
Feng Li
Raphael Norwitz 于2020年5月31日周日 上午8:55写道：
>
> On Thu, May 28, 2020 at 5:13 AM Dima Stepanov wrote:
> >
> > A socket write during vhost-user communication may trigger a disconnect
> > event, calling vhost_user_blk_disconnect() and clearing all the
> > vhost_dev structures holding data that vhost-user functions expect to
> > remain valid to roll back initialization correctly. Delay the cleanup to
> > keep vhost_dev structure valid.
> > There are two possible states to handle:
> > 1. RUN_STATE_PRELAUNCH: skip bh oneshot call and perform disconnect in
> > the caller routine.
> > 2. RUN_STATE_RUNNING: delay by using bh
> >
> > BH changes are based on the similar changes for the vhost-user-net
> > device:
> > commit e7c83a885f865128ae3cf1946f8cb538b63cbfba
> > "vhost-user: delay vhost_user_stop"
> >
> > Signed-off-by: Dima Stepanov
>
> Reviewed-by: Raphael Norwitz
>
> Li Feng - would you also like to sign off here?
>
> > ---
> > hw/block/vhost-user-blk.c | 38 +-
> > 1 file changed, 37 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> > index 9d8c0b3..76838e7 100644
> > --- a/hw/block/vhost-user-blk.c
> > +++ b/hw/block/vhost-user-blk.c
> > @@ -349,6 +349,19 @@ static void vhost_user_blk_disconnect(DeviceState *dev)
> > vhost_dev_cleanup(>dev);
> > }
> >
> > +static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
> > +
> > +static void vhost_user_blk_chr_closed_bh(void *opaque)
> > +{
> > +DeviceState *dev = opaque;
> > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > +VHostUserBlk *s = VHOST_USER_BLK(vdev);
> > +
> > +vhost_user_blk_disconnect(dev);
> > +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, vhost_user_blk_event,
> > +NULL, opaque, NULL, true);
> > +}
> > +
> > static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
> > {
> > DeviceState *dev = opaque;
> > @@ -363,7 +376,30 @@ static void vhost_user_blk_event(void *opaque,
> > QEMUChrEvent event)
> > }
> > break;
> > case CHR_EVENT_CLOSED:
> > -vhost_user_blk_disconnect(dev);
> > +/*
> > + * A close event may happen during a read/write, but vhost
> > + * code assumes the vhost_dev remains setup, so delay the
> > + * stop & clear. There are two possible paths to hit this
> > + * disconnect event:
> > + * 1. When VM is in the RUN_STATE_PRELAUNCH state. The
> > + * vhost_user_blk_device_realize() is a caller.
> > + * 2. In tha main loop phase after VM start.
> > + *
> > + * For p2 the disconnect event will be delayed. We can't
> > + * do the same for p1, because we are not running the loop
> > + * at this moment. So just skip this step and perform
> > + * disconnect in the caller function.
> > + *
> > + * TODO: maybe it is a good idea to make the same fix
> > + * for other vhost-user devices.
> > + */
> > +if (runstate_is_running()) {
> > +AioContext *ctx = qemu_get_current_aio_context();
> > +
> > +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, NULL, NULL,
> > +NULL, NULL, false);
> > +aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh,
> > opaque);
> > +}
> > break;
> > case CHR_EVENT_BREAK:
> > case CHR_EVENT_MUX_IN:
> > --
> > 2.7.4
> >
> >
Re: [PATCH v4 2/2] vhost-user-blk: delay vhost_user_blk_disconnect
On Thu, May 28, 2020 at 5:13 AM Dima Stepanov wrote:
>
> A socket write during vhost-user communication may trigger a disconnect
> event, calling vhost_user_blk_disconnect() and clearing all the
> vhost_dev structures holding data that vhost-user functions expect to
> remain valid to roll back initialization correctly. Delay the cleanup to
> keep vhost_dev structure valid.
> There are two possible states to handle:
> 1. RUN_STATE_PRELAUNCH: skip bh oneshot call and perform disconnect in
> the caller routine.
> 2. RUN_STATE_RUNNING: delay by using bh
>
> BH changes are based on the similar changes for the vhost-user-net
> device:
> commit e7c83a885f865128ae3cf1946f8cb538b63cbfba
> "vhost-user: delay vhost_user_stop"
>
> Signed-off-by: Dima Stepanov
Reviewed-by: Raphael Norwitz
Li Feng - would you also like to sign off here?
> ---
> hw/block/vhost-user-blk.c | 38 +-
> 1 file changed, 37 insertions(+), 1 deletion(-)
>
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index 9d8c0b3..76838e7 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -349,6 +349,19 @@ static void vhost_user_blk_disconnect(DeviceState *dev)
> vhost_dev_cleanup(>dev);
> }
>
> +static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
> +
> +static void vhost_user_blk_chr_closed_bh(void *opaque)
> +{
> +DeviceState *dev = opaque;
> +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> +VHostUserBlk *s = VHOST_USER_BLK(vdev);
> +
> +vhost_user_blk_disconnect(dev);
> +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, vhost_user_blk_event,
> +NULL, opaque, NULL, true);
> +}
> +
> static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
> {
> DeviceState *dev = opaque;
> @@ -363,7 +376,30 @@ static void vhost_user_blk_event(void *opaque,
> QEMUChrEvent event)
> }
> break;
> case CHR_EVENT_CLOSED:
> -vhost_user_blk_disconnect(dev);
> +/*
> + * A close event may happen during a read/write, but vhost
> + * code assumes the vhost_dev remains setup, so delay the
> + * stop & clear. There are two possible paths to hit this
> + * disconnect event:
> + * 1. When VM is in the RUN_STATE_PRELAUNCH state. The
> + * vhost_user_blk_device_realize() is a caller.
> + * 2. In tha main loop phase after VM start.
> + *
> + * For p2 the disconnect event will be delayed. We can't
> + * do the same for p1, because we are not running the loop
> + * at this moment. So just skip this step and perform
> + * disconnect in the caller function.
> + *
> + * TODO: maybe it is a good idea to make the same fix
> + * for other vhost-user devices.
> + */
> +if (runstate_is_running()) {
> +AioContext *ctx = qemu_get_current_aio_context();
> +
> +qemu_chr_fe_set_handlers(>chardev, NULL, NULL, NULL, NULL,
> +NULL, NULL, false);
> +aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh,
> opaque);
> +}
> break;
> case CHR_EVENT_BREAK:
> case CHR_EVENT_MUX_IN:
> --
> 2.7.4
>
>
[PATCH v4 2/2] vhost-user-blk: delay vhost_user_blk_disconnect
A socket write during vhost-user communication may trigger a disconnect
event, calling vhost_user_blk_disconnect() and clearing all the
vhost_dev structures holding data that vhost-user functions expect to
remain valid to roll back initialization correctly. Delay the cleanup to
keep vhost_dev structure valid.
There are two possible states to handle:
1. RUN_STATE_PRELAUNCH: skip bh oneshot call and perform disconnect in
the caller routine.
2. RUN_STATE_RUNNING: delay by using bh
BH changes are based on the similar changes for the vhost-user-net
device:
commit e7c83a885f865128ae3cf1946f8cb538b63cbfba
"vhost-user: delay vhost_user_stop"
Signed-off-by: Dima Stepanov
---
hw/block/vhost-user-blk.c | 38 +-
1 file changed, 37 insertions(+), 1 deletion(-)
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 9d8c0b3..76838e7 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -349,6 +349,19 @@ static void vhost_user_blk_disconnect(DeviceState *dev)
vhost_dev_cleanup(>dev);
}
+static void vhost_user_blk_event(void *opaque, QEMUChrEvent event);
+
+static void vhost_user_blk_chr_closed_bh(void *opaque)
+{
+DeviceState *dev = opaque;
+VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+VHostUserBlk *s = VHOST_USER_BLK(vdev);
+
+vhost_user_blk_disconnect(dev);
+qemu_chr_fe_set_handlers(>chardev, NULL, NULL, vhost_user_blk_event,
+NULL, opaque, NULL, true);
+}
+
static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
{
DeviceState *dev = opaque;
@@ -363,7 +376,30 @@ static void vhost_user_blk_event(void *opaque,
QEMUChrEvent event)
}
break;
case CHR_EVENT_CLOSED:
-vhost_user_blk_disconnect(dev);
+/*
+ * A close event may happen during a read/write, but vhost
+ * code assumes the vhost_dev remains setup, so delay the
+ * stop & clear. There are two possible paths to hit this
+ * disconnect event:
+ * 1. When VM is in the RUN_STATE_PRELAUNCH state. The
+ * vhost_user_blk_device_realize() is a caller.
+ * 2. In tha main loop phase after VM start.
+ *
+ * For p2 the disconnect event will be delayed. We can't
+ * do the same for p1, because we are not running the loop
+ * at this moment. So just skip this step and perform
+ * disconnect in the caller function.
+ *
+ * TODO: maybe it is a good idea to make the same fix
+ * for other vhost-user devices.
+ */
+if (runstate_is_running()) {
+AioContext *ctx = qemu_get_current_aio_context();
+
+qemu_chr_fe_set_handlers(>chardev, NULL, NULL, NULL, NULL,
+NULL, NULL, false);
+aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque);
+}
break;
case CHR_EVENT_BREAK:
case CHR_EVENT_MUX_IN:
--
2.7.4
