Messages in this thread | | | Subject | Re: [PATCH v5 11/13] KVM: s390: implement mediated device open callback | From | Tony Krowiak <> | Date | Mon, 11 Jun 2018 08:56:02 -0400 |
| |
On 06/11/2018 05:23 AM, Pierre Morel wrote: > On 08/06/2018 23:59, Tony Krowiak wrote: >> On 06/07/2018 01:15 PM, Pierre Morel wrote: >>> > > ...snip... > >>>>> >>>>>> >>>>>> Why maintain a list of kvm_ap_matrix structures if we don't have >>>>>> to; it is stored >>>>>> with the mediated matrix device which is passed in to all of the >>>>>> vfio_ap driver >>>>>> callbacks. >>>>> >>>>> Because using the vm_list which is a static in kvm makes you stick >>>>> inside the kvm code. >> >> I understand your point here, but even if we did maintain a list of >> kvm_ap_matrix structures, >> we still need the kvm code to configure the guest's CRYCB and >> eventually ECA.28. There is >> also code in kvm-ap.c that is called from KVM. > > The only code from kvm-ap which is called from KVM is temporary code > waiting for Harald to offer the clean interface to AP instructions. > >> The idea behind kvm-ap.c is that all code >> related to configuration of AP structures in KVM is in this one spot. > > This I understand, but the code can be in one spot inside VFIO_AP instead > of inside KVM. > Putting the code inside KVM induce dependencies between KVM and AP > while the kvm/vfio interface allows to avoid this dependency. > > > The purpose of VFIO_AP is to handle the CRYCB, all get/clear/set crycb > masks > functions should be in VFIO AP. > > If we use wrappers in KVM, since the CRYCB is an a SIE extension, > it is legitimate, the KVM interface to the CRYCB should only > handle bitmaps and be unaware of the vfio_ap internal structures. > > > Another concern, the kvm_ap_validate_queue_sharing() should not be > inside KVM because it is a decision of current VFIO_AP driver > to not share the queues between guest of level 2. > > The Z architecture does not allow to share AP queues between > guests of level 1 but we could re-engineer the AP bus and the ' > VFIO AP to offer queue sharing for guest level 2. > > This would be a new VFIO_AP driver (and an AP bus extension). > We should not have to change KVM for this.
Based on your, Halil's and Janosch's comments, I will make the changes.
> > > > Regards, > > Pierre > > >> >>> >>> >>> >> >
| |