| Message ID | 20220128121912.509006-43-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: ARMv8.3/8.4 Nested Virtualization support | expand |
Hi, On Fri, Jan 28, 2022 at 12:18:50PM +0000, Marc Zyngier wrote: > When entering a L2 guest (nested virt enabled, but not in hypervisor > context), we need to honor the traps the L1 guest has asked enabled. > > For now, just OR the guest's HCR_EL2 into the host's. We may have to do > some filtering in the future though. Hmm... looks to me like the filtering is already implemented via the HCR_GUEST_NV_FILTER_FLAGS. Or am I misunderstanding something? > > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > arch/arm64/kvm/hyp/vhe/switch.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c > index 0e164cc8e913..5e8eafac27c6 100644 > --- a/arch/arm64/kvm/hyp/vhe/switch.c > +++ b/arch/arm64/kvm/hyp/vhe/switch.c > @@ -78,6 +78,11 @@ static void __activate_traps(struct kvm_vcpu *vcpu) > if (!vcpu_el2_tge_is_set(vcpu)) > hcr |= HCR_AT | HCR_TTLB; > } > + } else if (vcpu_has_nv(vcpu)) { > + u64 vhcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); > + > + vhcr_el2 &= ~HCR_GUEST_NV_FILTER_FLAGS; > + hcr |= vhcr_el2; This makes sense, we only the guest to add extra traps on top of what KVM already traps, not remove traps from what KVM has configured. However, HCR_EL2.FIEN (bit 47) disables traps when the bit is 1. Shouldn't it be part of the HCR_GUEST_NV_FILTER_FLAGS? Thanks, Alex > } > > ___activate_traps(vcpu, hcr); > -- > 2.30.2 >
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 0e164cc8e913..5e8eafac27c6 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -78,6 +78,11 @@ static void __activate_traps(struct kvm_vcpu *vcpu) if (!vcpu_el2_tge_is_set(vcpu)) hcr |= HCR_AT | HCR_TTLB; } + } else if (vcpu_has_nv(vcpu)) { + u64 vhcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + + vhcr_el2 &= ~HCR_GUEST_NV_FILTER_FLAGS; + hcr |= vhcr_el2; } ___activate_traps(vcpu, hcr);
When entering a L2 guest (nested virt enabled, but not in hypervisor context), we need to honor the traps the L1 guest has asked enabled. For now, just OR the guest's HCR_EL2 into the host's. We may have to do some filtering in the future though. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/hyp/vhe/switch.c | 5 +++++ 1 file changed, 5 insertions(+)