linux-kernel - [PATCH v2 11/18] KVM: arm64: don't trap Statistical Profiling controls to EL2

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Message-Id: <20191220143025.33853-12-andrew.murray@arm.com>
Date:   Fri, 20 Dec 2019 14:30:18 +0000
From:   Andrew Murray <andrew.murray@....com>
To:     Marc Zyngier <marc.zyngier@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>
Cc:     Sudeep Holla <sudeep.holla@....com>, kvmarm@...ts.cs.columbia.edu,
        linux-arm-kernel@...ts.infradead.org, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Mark Rutland <mark.rutland@....com>
Subject: [PATCH v2 11/18] KVM: arm64: don't trap Statistical Profiling controls to EL2

As we now save/restore the profiler state there is no need to trap
accesses to the statistical profiling controls. Let's unset the
_TPMS bit.

Signed-off-by: Andrew Murray <andrew.murray@....com>
---
 arch/arm64/kvm/debug.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 43487f035385..07ca783e7d9e 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -88,7 +88,6 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
  *  - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
  *  - Debug ROM Address (MDCR_EL2_TDRA)
  *  - OS related registers (MDCR_EL2_TDOSA)
- *  - Statistical profiler (MDCR_EL2_TPMS/MDCR_EL2_E2PB)
  *
  * Additionally, KVM only traps guest accesses to the debug registers if
  * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
@@ -111,7 +110,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 	 */
 	vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
 	vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
-				MDCR_EL2_TPMS |
 				MDCR_EL2_TPMCR |
 				MDCR_EL2_TDRA |
 				MDCR_EL2_TDOSA);
-- 
2.21.0