From: Will Deacon <will.deacon@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, ard.biesheuvel@linaro.org,
marc.zyngier@arm.com, lorenzo.pieralisi@arm.com,
christoffer.dall@linaro.org, linux-kernel@vger.kernel.org,
shankerd@codeaurora.org, jnair@caviumnetworks.com,
Will Deacon <will.deacon@arm.com>
Subject: [PATCH v3 09/13] arm64: KVM: Make PSCI_VERSION a fast path
Date: Mon, 8 Jan 2018 17:32:34 +0000 [thread overview]
Message-ID: <1515432758-26440-10-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1515432758-26440-1-git-send-email-will.deacon@arm.com>
From: Marc Zyngier <marc.zyngier@arm.com>
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>
---
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 <linux/types.h>
#include <linux/jump_label.h>
+#include <uapi/linux/psci.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
@@ -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
next prev parent reply other threads:[~2018-01-08 17:34 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 17:32 [PATCH v3 00/13] arm64 kpti hardening and variant 2 workarounds Will Deacon
2018-01-08 17:32 ` [PATCH v3 01/13] arm64: use RET instruction for exiting the trampoline Will Deacon
2018-01-08 17:32 ` [PATCH v3 02/13] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry Will Deacon
2018-01-09 17:17 ` Christoph Hellwig
2018-01-10 19:26 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 03/13] arm64: Take into account ID_AA64PFR0_EL1.CSV3 Will Deacon
2018-01-08 17:32 ` [PATCH v3 04/13] arm64: cpufeature: Pass capability structure to ->enable callback Will Deacon
2018-01-08 17:32 ` [PATCH v3 05/13] drivers/firmware: Expose psci_get_version through psci_ops structure Will Deacon
2018-01-08 17:32 ` [PATCH v3 06/13] arm64: Move post_ttbr_update_workaround to C code Will Deacon
2018-01-08 17:32 ` [PATCH v3 07/13] arm64: Add skeleton to harden the branch predictor against aliasing attacks Will Deacon
2018-01-09 12:55 ` Philippe Ombredanne
2018-01-08 17:32 ` [PATCH v3 08/13] arm64: KVM: Use per-CPU vector when BP hardening is enabled Will Deacon
2018-01-08 17:32 ` Will Deacon [this message]
2018-01-08 17:32 ` [PATCH v3 10/13] arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75 Will Deacon
2018-01-08 17:32 ` [PATCH v3 11/13] arm64: Implement branch predictor hardening for affected Cortex-A CPUs Will Deacon
2018-01-09 16:12 ` Suzuki K Poulose
2018-01-15 11:51 ` Marc Zyngier
2018-01-15 18:01 ` Catalin Marinas
2018-01-08 17:32 ` [PATCH v3 12/13] arm64: Implement branch predictor hardening for Falkor Will Deacon
2018-01-12 17:58 ` Shanker Donthineni
2018-01-08 17:32 ` [PATCH v3 13/13] arm64: cputype: Add MIDR values for Cavium ThunderX2 CPUs Will Deacon
2018-01-08 18:53 ` [PATCH v3 00/13] arm64 kpti hardening and variant 2 workarounds Catalin Marinas
2018-01-09 14:07 ` Matthias Brugger
2018-01-12 15:58 ` Catalin Marinas
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