linux-kernel - [PATCH v2 11/15] arm64: KVM/debug: trap all accesses to SPE controls at EL1

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Date:   Thu, 23 May 2019 11:34:58 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     kvmarm@...ts.cs.columbia.edu, linux-arm-kernel@...ts.infradead.org
Cc:     Sudeep Holla <sudeep.holla@....com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Christoffer Dall <christoffer.dall@....com>,
        Marc Zyngier <marc.zyngier@....com>,
        James Morse <james.morse@....com>,
        Suzuki K Pouloze <suzuki.poulose@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        Julien Thierry <julien.thierry@....com>
Subject: [PATCH v2 11/15] arm64: KVM/debug: trap all accesses to SPE controls at EL1

Now that we have all the save/restore mechanism in place, lets enable
trapping of accesses to SPE profiling buffer controls at EL1 to EL2.
This will also change the translation regime used by buffer from EL2
stage 1 to EL1 stage 1 on VHE systems.

Signed-off-by: Sudeep Holla <sudeep.holla@....com>
---
 arch/arm64/kvm/hyp/switch.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 844f0dd7a7f0..881901825a85 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -110,6 +110,7 @@ static void activate_traps_vhe(struct kvm_vcpu *vcpu)
 
 	write_sysreg(val, cpacr_el1);
 
+	write_sysreg(vcpu->arch.mdcr_el2 | 2 << MDCR_EL2_E2PB_SHIFT, mdcr_el2);
 	write_sysreg(kvm_get_hyp_vector(), vbar_el1);
 }
 NOKPROBE_SYMBOL(activate_traps_vhe);
@@ -127,6 +128,7 @@ static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu)
 		__activate_traps_fpsimd32(vcpu);
 	}
 
+	write_sysreg(vcpu->arch.mdcr_el2 | 2 << MDCR_EL2_E2PB_SHIFT, mdcr_el2);
 	write_sysreg(val, cptr_el2);
 }
 
-- 
2.17.1