Re: [Qemu-devel] Using AHCI drives in qemu

[Andreas Färber]

Am 30.11.2011 13:20, schrieb Daniel P. Berrange:
> On Wed, Nov 30, 2011 at 12:11:45PM +0000, Chris Webb wrote:
>> Possible a stupid question, but noting the new AHCI support in qemu, how do
>> I specify an AHCI drive to attach to a qemu VM?
>>
>> I can create IDE, SCSI and virtio drives with
>>
>>   -drive if=ide,bus=M,unit=N,...
>>   -drive if=scsi,bus=M,unit=N,...
>>   -drive if=virtio,index=N,...
>>
>> but when I attempted to test AHCI, a variety of plausible things I tried
>> like
>>
>>   -drive if=ahci,...
>>   -drive if=ide-ahci,...
>>   -drive if=ide,bus=ahci.0,...
>>
>> all failed. There's no mention of AHCI in qemu-options.hx or qemu-doc.texi,
>> nor anything in the git commit log history about using this new drive type.
> 
> Using  -drive with an if=XXX which is anything other than 'none' is the
> deprecated / legacy syntax. The way libvirt does AHCI is to use the more
> verbose/modern syntax:
> 
>     -device ahci,id=ahci0
>     -drive  
> if=none,file=/var/lib/libvirt/images/test/disk0.raw,format=raw,id=drive-sata0-0-0
>     -device ide-drive,bus=ahci0.0,drive=drive-sata0-0-0,id=sata0-0-0
> 
> The first -device there creates the AHCI controller. The -drive specifies
> the disk backing store that will be used. The last -device there connects
> the drive to the ACHI controller as an ide-drive.

Also note that -device ide-cd on ahci bus is known broken, and ahci is
not yet migratable (working on it).

Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg