Re: [Qemu-devel] [PATCH 1/1] block: fix inability to start VM with native AIO

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 12/22/2015 07:59 AM, Denis V. Lunev wrote:
> error: Failed to start domain rhel7
> error: internal error: process exited while connecting to monitor:
>     2015-12-22T06:55:18.812637Z qemu-system-x86_64:
>     -drive file=/var/lib/libvirt/images/rhel7.qcow2,if=none,
>         id=drive-scsi0-0-0-0,format=qcow2,cache=none,aio=native:
>     aio=native was specified, but it requires cache.direct=on,
>     which was not specified.
> 
> cache=none option was specified as seen above while the VM is unable to
> start. The patch properly passed BDRV_O_NOCACHE to underlying layer.
> 
> The problem is revealed with
>     commit d657c0c289e944fc22289f5c318f48da87d79dcb
>     Author: Kevin Wolf <kwolf@redhat.com>
>     Date:   Tue Dec 15 11:35:36 2015 +0100
> 
>         raw-posix: Make aio=native option binding
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Kevin Wolf <kwolf@redhat.com>

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>

Without this patch all libvirt xmls with
cache='none' io='native'
are broken. We should apply this patch (or something else)
soon.





> ---
>  block.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/block.c b/block.c
> index 411edbf..fe0fbbc 100644
> --- a/block.c
> +++ b/block.c
> @@ -990,6 +990,7 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
>      bs->opaque = g_malloc0(drv->instance_size);
> 
>      /* Apply cache mode options */
> +    update_flags_from_options(&open_flags, opts);
>      update_flags_from_options(&bs->open_flags, opts);
>      bdrv_set_enable_write_cache(bs, bs->open_flags & BDRV_O_CACHE_WB);
>