Re: [PATCH v3] qemu: send stop event after bdrv_flush_all

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Dec 05, 2023 at 04:19:03AM -0500, tianren@smartx.com wrote:
> From: Tianren Zhang <tianren@smartx.com>
> 
> The stop process is not finished until bdrv_flush_all
> is done. Some users (e.g., libvirt) detect the STOP
> event and invokes some lock release logic to revoke
> the disk lock held by current qemu when such event is
> emitted. In such case, if the bdrv_flush_all is after
> the stop event, it's possible that the disk lock is
> released while the qemu is still waiting for I/O.
> Therefore, it's better to have the stop event generated
> after the whole stop process is done, so we can
> guarantee to users that the stop process is finished
> when they get the STOP event.
> 
> Signed-off-by: Tianren Zhang <tianren@smartx.com>
> ---
> v2: do not call runstate_is_running twice
> v3: remove irrelevant info from commit msg
> ---
>  system/cpus.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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