On 06/24/2014 06:17 PM, Markus Armbruster wrote: > Alexey Kardashevskiy <a...@ozlabs.ru> writes: > >> On 06/24/2014 03:15 PM, Paolo Bonzini wrote: >>> Il 23/06/2014 23:35, Alexey Kardashevskiy ha scritto: >>>> nec-usb-xhci is off for PC_COMPAT_1_3 because of what? PIIX emulation was >>>> broken in 1.3? Or nec-usb-xhci? >>> >>> nec-usb-xhci is not "off". >> >> Yes, my bad, I understood (but explained this wrong) that XHCI is enabled >> but without MSI. >> >> >>> >>> .driver = "nec-usb-xhci",\ >>> .property = "msi",\ >>> .value = "off",\ >>> >>> What's off is MSI (and MSI-X), because it wasn't implemented. >>> >>>> If it is the latter, why is the tweak limited by PC? >>> >>> Because at the time nobody cared about migration compatibility (even now >>> only pSeries is starting to care). >> >> >> "only pSeries"? There are plenty of x86 machines already and if it is not >> for migration support, then what are they all for? :) > > At the time, nobody *else* cared. Only PC did.
Ah. Misinterpret. My bad. Ok. > > Back then gerd created a way to do the compatibility stuff without > getting into the other target's hair: compat_props. They've served us > well enough, but now that more targets get interested in migration, > their shortcomings start to hurt. Having to duplicate device > compatibility gunk in multiple places, all far away from the device, is > decidedly suboptimal. Better ideas welcome. I would suggest moving PC_COMPAT_X_Y things to platform-independent place but "[RFC v2 00/39] Convert PC machine-types to QOM classes" is already huge and complicated, and also "pseries" does not really need stuff below 1.6, may be it is not worth it... -- Alexey