From: Marc Zyngier <maz@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>,
Andre Przywara <andre.przywara@arm.com>,
Andrew Scull <ascull@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Howard Zhang <Howard.Zhang@arm.com>, Jia He <justin.he@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Quentin Perret <qperret@google.com>,
Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Subject: [PATCH 5/8] KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available
Date: Fri, 5 Mar 2021 18:52:51 +0000 [thread overview]
Message-ID: <20210305185254.3730990-6-maz@kernel.org> (raw)
In-Reply-To: <20210305185254.3730990-1-maz@kernel.org>
When running under a nesting hypervisor, it isn't guaranteed that
the virtual HW will include a PMU. In which case, let's not try
to access the PMU registers in the world switch, as that'd be
deadly.
Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210209114844.3278746-3-maz@kernel.org
---
arch/arm64/kernel/image-vars.h | 3 +++
arch/arm64/kvm/hyp/include/hyp/switch.h | 9 ++++++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 23f1a557bd9f..5aa9ed1e9ec6 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -101,6 +101,9 @@ KVM_NVHE_ALIAS(__stop___kvm_ex_table);
/* Array containing bases of nVHE per-CPU memory regions. */
KVM_NVHE_ALIAS(kvm_arm_hyp_percpu_base);
+/* PMU available static key */
+KVM_NVHE_ALIAS(kvm_arm_pmu_available);
+
#endif /* CONFIG_KVM */
#endif /* __ARM64_KERNEL_IMAGE_VARS_H */
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 54f4860cd87c..6c1f51f25eb3 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -90,15 +90,18 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
* counter, which could make a PMXEVCNTR_EL0 access UNDEF at
* EL1 instead of being trapped to EL2.
*/
- write_sysreg(0, pmselr_el0);
- write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
+ if (kvm_arm_support_pmu_v3()) {
+ write_sysreg(0, pmselr_el0);
+ write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
+ }
write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
}
static inline void __deactivate_traps_common(void)
{
write_sysreg(0, hstr_el2);
- write_sysreg(0, pmuserenr_el0);
+ if (kvm_arm_support_pmu_v3())
+ write_sysreg(0, pmuserenr_el0);
}
static inline void ___activate_traps(struct kvm_vcpu *vcpu)
--
2.29.2
next prev parent reply other threads:[~2021-03-05 18:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 16:49 [GIT PULL] KVM/arm64 fixes for 5.12, take #1 Marc Zyngier
2021-03-05 17:27 ` Paolo Bonzini
2021-03-05 18:47 ` Marc Zyngier
2021-03-05 18:52 ` [PATCH 0/8] " Marc Zyngier
2021-03-05 18:52 ` [PATCH 1/8] KVM: arm64: nvhe: Save the SPE context early Marc Zyngier
2021-03-05 18:52 ` [PATCH 2/8] KVM: arm64: Avoid corrupting vCPU context register in guest exit Marc Zyngier
2021-03-05 18:52 ` [PATCH 3/8] KVM: arm64: Fix nVHE hyp panic host context restore Marc Zyngier
2021-03-05 18:52 ` [PATCH 4/8] KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key Marc Zyngier
2021-03-05 18:52 ` Marc Zyngier [this message]
2021-03-05 18:52 ` [PATCH 6/8] KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config() Marc Zyngier
2021-03-05 18:52 ` [PATCH 7/8] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility Marc Zyngier
2021-03-15 12:55 ` Shameerali Kolothum Thodi
2021-03-15 14:36 ` Marc Zyngier
2021-03-05 18:52 ` [PATCH 8/8] KVM: arm64: Fix range alignment when walking page tables Marc Zyngier
2021-03-06 9:50 ` [PATCH 0/8] KVM/arm64 fixes for 5.12, take #1 Paolo Bonzini
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