diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-10-10 16:09:06 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-10-17 11:06:36 +0100 |
| commit | 562e530fd7707aad7fed953692d1835612238966 (patch) | |
| tree | c5c826ecc1cd23f3a57467f128c5e91caa3aa393 /arch/arm64/kvm | |
| parent | 9e1ff307c779ce1f0f810c7ecce3d95bbae40896 (diff) | |
KVM: arm64: Force ID_AA64PFR0_EL1.GIC=1 when exposing a virtual GICv3
Until now, we always let ID_AA64PFR0_EL1.GIC reflect the value
visible on the host, even if we were running a GICv2-enabled VM
on a GICv3+compat host.
That's fine, but we also now have the case of a host that does not
expose ID_AA64PFR0_EL1.GIC==1 despite having a vGIC. Yes, this is
confusing. Thank you M1.
Let's go back to first principles and expose ID_AA64PFR0_EL1.GIC=1
when a GICv3 is exposed to the guest. This also hides a GICv4.1
CPU interface from the guest which has no business knowing about
the v4.1 extension.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010150910.2911495-2-maz@kernel.org
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1d46e185f31e..0e8fc29df19c 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1075,6 +1075,11 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2); val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_CSV3); val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3); + if (irqchip_in_kernel(vcpu->kvm) && + vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) { + val &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_GIC); + val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_GIC), 1); + } break; case SYS_ID_AA64PFR1_EL1: val &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_MTE); |