Re: [PATCH v6 19/21] KVM: arm64: Emulate physical counter offsetting on non-ECV systems

2021-08-10 Thread Marc Zyngier
On Wed, 04 Aug 2021 09:58:17 +0100, Oliver Upton wrote: > > Unfortunately, ECV hasn't yet arrived in any tangible hardware. At the > same time, controlling the guest view of the physical counter-timer is > useful. Support guest counter-timer offsetting on non-ECV systems by > trapping guest

Re: [PATCH v6 19/21] KVM: arm64: Emulate physical counter offsetting on non-ECV systems

2021-08-05 Thread Oliver Upton
Hi Drew, On Wed, Aug 4, 2021 at 4:05 AM Andrew Jones wrote: > > +static bool ptimer_emulation_required(struct kvm_vcpu *vcpu) > > +{ > > + return timer_get_offset(vcpu_ptimer(vcpu)) && > > + !cpus_have_const_cap(ARM64_ECV); > > Whenever I see a static branch check and

[PATCH v6 19/21] KVM: arm64: Emulate physical counter offsetting on non-ECV systems

2021-08-04 Thread Oliver Upton
Unfortunately, ECV hasn't yet arrived in any tangible hardware. At the same time, controlling the guest view of the physical counter-timer is useful. Support guest counter-timer offsetting on non-ECV systems by trapping guest accesses to the physical counter-timer. Emulate reads of the physical

Re: [PATCH v6 19/21] KVM: arm64: Emulate physical counter offsetting on non-ECV systems

2021-08-04 Thread Andrew Jones
On Wed, Aug 04, 2021 at 08:58:17AM +, Oliver Upton wrote: > Unfortunately, ECV hasn't yet arrived in any tangible hardware. At the > same time, controlling the guest view of the physical counter-timer is > useful. Support guest counter-timer offsetting on non-ECV systems by > trapping guest