From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Thu, 4 Jan 2018 15:08:33 +0000 Subject: [PATCH 09/11] arm64: KVM: Make PSCI_VERSION a fast path In-Reply-To: <1515078515-13723-1-git-send-email-will.deacon@arm.com> References: <1515078515-13723-1-git-send-email-will.deacon@arm.com> Message-ID: <1515078515-13723-10-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Marc Zyngier For those CPUs that require PSCI to perform a BP invalidation, going all the way to the PSCI code for not much is a waste of precious cycles. Let's terminate that call as early as possible. Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon --- arch/arm64/kvm/hyp/switch.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 8d4f3c9d6dc4..4d273f6d0e69 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -17,6 +17,7 @@ #include #include +#include #include #include @@ -341,6 +342,18 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu)) goto again; + if (exit_code == ARM_EXCEPTION_TRAP && + (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC64 || + kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC32) && + vcpu_get_reg(vcpu, 0) == PSCI_0_2_FN_PSCI_VERSION) { + u64 val = PSCI_RET_NOT_SUPPORTED; + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) + val = 2; + + vcpu_set_reg(vcpu, 0, val); + goto again; + } + if (static_branch_unlikely(&vgic_v2_cpuif_trap) && exit_code == ARM_EXCEPTION_TRAP) { bool valid; -- 2.1.4