Messages in this thread | | | Subject | Re: [PATCH v4 15/15] s390: doc: detailed specifications for AP virtualization | From | Pierre Morel <> | Date | Tue, 17 Apr 2018 18:25:50 +0200 |
| |
On 17/04/2018 18:14, Tony Krowiak wrote: > On 04/16/2018 09:13 AM, Pierre Morel wrote: >> On 15/04/2018 23:22, Tony Krowiak wrote: >>> This patch provides documentation describing the AP architecture and >>> design concepts behind the virtualization of AP devices. It also >>> ...snip... >>> +The process for reserving an AP queue for use by a KVM guest is: >>> + >>> +* The vfio-ap driver during its initialization will perform the >>> following: >>> + * Create the 'vfio_ap' root device - /sys/devices/vfio_ap >>> + * Create the 'matrix' device in the 'vfio_ap' root >>> + * Register the matrix device with the device core >>> +* Register with the ap_bus for AP queue devices of type CEX4, CEX5 and >>> + CEX6 and to provide the vfio_ap driver's probe and remove >>> callback interfaces. >> >> I wonder why the type of card has anything to do with this driver. >> It should be transparent, the driver should be able to provide the >> matrix (APM/AQM/ADM) >> independently from the type of card in the slot. > > We've been down this road several times before. We are only supporting > virtualization of > CEX4 and newer cards. Also, the AP bus requires registering for > specific card types.
Yes I know, but the AP BUS design may be not the optimal for the AP Matrix. The AP Matrix is device independent. We just write/clear bits in a matrix and we do not care what is plugged.
So may be make clear that this device dependence is due to the actual AP BUS interface design.
> >> >> >> Regards, >> >> Pierre >> >
-- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
| |