Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sudeep Holla <sudeep.holla@arm.com>
To:     kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org
Cc:     Sudeep Holla <sudeep.holla@arm.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Christoffer Dall <christoffer.dall@arm.com>,
        Marc Zyngier <marc.zyngier@arm.com>,
        James Morse <james.morse@arm.com>,
        Suzuki K Pouloze <suzuki.poulose@arm.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Julien Thierry <julien.thierry@arm.com>
Subject: [PATCH v2 03/15] arm64: KVM: reset E2PB correctly in MDCR_EL2 when exiting the guest(VHE)
Date:   Thu, 23 May 2019 11:34:50 +0100
Message-Id: <20190523103502.25925-4-sudeep.holla@arm.com>
In-Reply-To: <20190523103502.25925-1-sudeep.holla@arm.com>
References: <20190523103502.25925-1-sudeep.holla@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On VHE systems, the reset value for MDCR_EL2.E2PB=b00 which defaults
to profiling buffer using the EL2 stage 1 translations. However if the
guest are allowed to use profiling buffers changing E2PB settings, we
need to ensure we resume back MDCR_EL2.E2PB=b00. Currently we just
do bitwise '&' with MDCR_EL2_E2PB_MASK which will retain the value.

So fix it by clearing all the bits in E2PB.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 arch/arm64/kvm/hyp/switch.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 22b4c335e0b2..9b2461138ddc 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -202,9 +202,7 @@ void deactivate_traps_vhe_put(void)
 {
 	u64 mdcr_el2 = read_sysreg(mdcr_el2);
 
-	mdcr_el2 &= MDCR_EL2_HPMN_MASK |
-		    MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT |
-		    MDCR_EL2_TPMS;
+	mdcr_el2 &= MDCR_EL2_HPMN_MASK | MDCR_EL2_TPMS;
 
 	write_sysreg(mdcr_el2, mdcr_el2);
 
-- 
2.17.1