Re: [Qemu-devel] win7 boot failure with commit f68ec83 - ide: Set BSY bit during FLUSH

["Andreas Färber" <afaerber@suse.de>]

Hi,

Am 09.07.2013 22:27, schrieb Michael S. Tsirkin:
> I am using this command line:
> qemu-system-x86_64 -m 512 -enable-kvm -drive
> id=disk,file=./images/win7-x86.qcow2,if=none -device ahci,id=ahci
> -device ide-drive,drive=disk,bus=ahci.0 -cdrom
> ./images/en_windows_7_ultimate_x86_dvd_x15-65921.iso  -monitor stdio
> -cpu kvm64 -snapshot
> 
> and windows 7 does not boot.

The same was recently reported for q35 - Kevin found the cause but I
haven't noticed a proposed solution yet.

Andreas

> This happens starting from this commit:
> 
> commit f68ec8379e88502b4841a110c070e9b118d3151c
> Author: Andreas Färber <afaerber@suse.de>
> Date:   Wed Jun 5 15:17:57 2013 +0200
> 
>     ide: Set BSY bit during FLUSH
>     
>     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) <arei.gonglei@huawei.com>
>     Signed-off-by: Andreas Färber <afaerber@suse.de>
>     Signed-off-by: Kevin Wolf <kwolf@redhat.com>
>     Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> 
> 
> guest starts booting but never completes boot - it just keeps flashing
> the flag image.  Boots fine with previous commit:
> commit c27d565604038c1572b16dd1cd06e277e6ef02e2
> 
> However, reverting f68ec8379e88502b4841a110c070e9b118d3151c on
> current master still has the hang on boot
> behaviour - possibly a separate issue, I'll have to redo the bisect
> to find out.
> 


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