Re: [Qemu-devel] [PATCH 4/5] Add generic drive hotplugging

[Alexander Graf <agraf@suse.de>]

On 24.08.2010, at 00:23, Alexander Graf wrote:

> 
> On 24.08.2010, at 00:21, Anthony Liguori wrote:
> 
>> On 08/23/2010 05:02 PM, Alexander Graf wrote:
>>> The monitor command for hotplugging is in i386 specific code. This is just
>>> plain wrong, as S390 just learned how to do hotplugging too and needs to
>>> get drives for that.
>>> 
>>> So let's add a generic copy to generic code that handles drive_add in a
>>> way that doesn't have pci dependencies.
>>> 
>>> I'm not fully happy with the patch as is. IMHO there should only be a
>>> single target agnostic drive_hot_add function available. How we could
>>> potentially fit IF_SCSI in there I don't know though.
>>> 
>>> Signed-off-by: Alexander Graf<agraf@suse.de>
>>> 
>> 
>> I think you really want device_add plus a blockdev_add.
> 
> Device_add already works with this set and only required minor changes the s390 specific code. So that part was pretty slick :). The part that didn't work was the drive_add one.
> 
> What is blockdev_add supposed to be? drive_add without IF_SCSI?

To be a bit more precise on how things work with this set:

(qemu) drive_add 0 id=my_disk,if=none,file=/dev/null
OK
(qemu) device_add virtio-blk-s390,drive=my_disk,id=new_disk

gives me a working new virtio disk in the VM that's mapped to /dev/null :).


Alex