From d385584226c55fc6d866a912a7cb6b5b13293a3c Mon Sep 17 00:00:00 2001
From: Marc Zyngier <marc.zyngier@arm.com>
Date: Wed, 3 Jan 2018 16:38:37 +0000
Subject: [PATCH 13/24] arm64: KVM: Make PSCI_VERSION a fast path
Git-commit: 90348689d500410ca7a55624c667f956771dce7f
Patch-mainline: v4.16-rc1
References: bsc#1068032
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 <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
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 75c8e83f022a..8c7505b8c5be 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -17,6 +17,7 @@
#include <linux/types.h>
#include <linux/jump_label.h>
+#include <uapi/linux/psci.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
@@ -322,6 +323,18 @@ 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;
--
2.11.0