Re: [Qemu-devel] [PATCH v2 3/4] ide: Set BSY bit during FLUSH

[Alex Williamson]

On Wed, 2013-06-05 at 15:17 +0200, Kevin Wolf wrote:
> From: Andreas Färber <address@hidden>
> 
> The implementation of the ATA FLUSH command invokes a flush at the block
> layer, which may on raw files on POSIX entail a synchronous fdatasync().
> This may in some cases take so long that the SLES 11 SP1 guest driver
> reports I/O errors and filesystems get corrupted or remounted read-only.
> 
> Avoid this by setting BUSY_STAT, so that the guest is made aware we are
> in the middle of an operation and no ATA commands are attempted to be
> processed concurrently.
> 
> Addresses BNC#637297.
> 
> Suggested-by: Gonglei (Arei) <address@hidden>
> Signed-off-by: Andreas Färber <address@hidden>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  hw/ide/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index c7a8041..9926d92 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -814,6 +814,7 @@ void ide_flush_cache(IDEState *s)
>          return;
>      }
>  
> +    s->status |= BUSY_STAT;
>      bdrv_acct_start(s->bs, &s->acct, 0, BDRV_ACCT_FLUSH);
>      bdrv_aio_flush(s->bs, ide_flush_cb, s);
>  }


I can no longer boot win7 x64 on q35 with IDE using a qcow2 image.  git
bisect determined this patch is the culprit.

-M q35 -nodefconfig -readconfig docs/q35-chipset.cfg -drive
file=image.qcow2,if=none,id=mydisk -device
ide-drive,drive=mydisk,bus=ide.0

Thanks,
Alex