From: Marc Zyngier Date: Thu, 30 Oct 2025 12:27:07 +0000 (+0000) Subject: KVM: arm64: Limit clearing of ID_{AA64PFR0,PFR1}_EL1.GIC to userspace irqchip X-Git-Tag: v6.18-rc6~42^2~3^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=50e7cce81b9b2fbd6f0104c1698959d45ce3cf58;p=thirdparty%2Flinux.git KVM: arm64: Limit clearing of ID_{AA64PFR0,PFR1}_EL1.GIC to userspace irqchip Now that the idreg's GIC field is in sync with the irqchip, limit the runtime clearing of these fields to the pathological case where we do not have an in-kernel GIC. While we're at it, use the existing API instead of open-coded accessors to access the ID regs. Fixes: 5cb57a1aff755 ("KVM: arm64: Zero ID_AA64PFR0_EL1.GIC when no GICv3 is presented to the guest") Reviewed-by: Oliver Upton Link: https://patch.msgid.link/20251030122707.2033690-4-maz@kernel.org Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ad82264c6cbe..8ae2bca81614 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -5609,11 +5609,13 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu) guard(mutex)(&kvm->arch.config_lock); - if (!(static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) && - irqchip_in_kernel(kvm) && - kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)) { - kvm->arch.id_regs[IDREG_IDX(SYS_ID_AA64PFR0_EL1)] &= ~ID_AA64PFR0_EL1_GIC_MASK; - kvm->arch.id_regs[IDREG_IDX(SYS_ID_PFR1_EL1)] &= ~ID_PFR1_EL1_GIC_MASK; + if (!irqchip_in_kernel(kvm)) { + u64 val; + + val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC; + kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val); + val = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC; + kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, val); } if (vcpu_has_nv(vcpu)) {