Daniel P. Berrange wrote: > On Tue, Aug 24, 2010 at 12:02:30AM +0200, 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. >> > > I'm not sure that this patch is actually neccessary. Via a undocumented, > sick, dirty hack, you can already use the current drive_add command > without a PCI address, for both virtio + scsi. In fact not using the > PCI address with drive_add is the preferred approach in the new qdev > world even on x86 >
It is certainly necessary since the current code is in a big fat #if defined(TARGET_I386) block :). > The key is that you should use if=none for all cases. Here are two > examples of how libvirt does it currently: > > VirtIO: > > drive_add dummy > file=/var/lib/libvirt/images/data.img,if=none,id=drive-virtio-disk1,format=raw > device_add > virtio-blk-pci,bus=pci.0,addr=0x0,drive=drive-virtio-disk1,id=virtio-disk1' > > SCSI: > > drive_add dummy > file=/var/lib/libvirt/images/data.img,if=none,id=drive-scsi0-0-1,format=raw' > device_add > scsi-disk,bus=scsi0.0,scsi-id=1,drive=drive-scsi0-0-1,id=scsi0-0-1 > > The 'dummy' value there can be absolutely anything you want. > It is totaly ignored when QEMU sees if=none in 2nd arg. > I'd be all for removing the pci-hotplug.c version of drive_add then. But I think the IF_SCSI option there is to append a drive to an existing SCSI bus, no? Alex
