linux-kernel - [PATCH 4.9 11/51] arm64/kvm: consistently handle host HCR

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Date:   Mon, 21 Jan 2019 14:44:07 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Marc Zyngier <marc.zyngier@....com>,
        Richard Henderson <richard.henderson@...aro.org>,
        Mark Rutland <mark.rutland@....com>,
        Christoffer Dall <christoffer.dall@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>,
        kvmarm@...ts.cs.columbia.edu,
        Kristina Martsenko <kristina.martsenko@....com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 11/51] arm64/kvm: consistently handle host HCR_EL2 flags

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Backport of upstream commit 4eaed6aa2c628101246bcabc91b203bfac1193f8 ]

In KVM we define the configuration of HCR_EL2 for a VHE HOST in
HCR_HOST_VHE_FLAGS, but we don't have a similar definition for the
non-VHE host flags, and open-code HCR_RW. Further, in head.S we
open-code the flags for VHE and non-VHE configurations.

In future, we're going to want to configure more flags for the host, so
lets add a HCR_HOST_NVHE_FLAGS defintion, and consistently use both
HCR_HOST_VHE_FLAGS and HCR_HOST_NVHE_FLAGS in the kvm code and head.S.

We now use mov_q to generate the HCR_EL2 value, as we use when
configuring other registers in head.S.

Reviewed-by: Marc Zyngier <marc.zyngier@....com>
Reviewed-by: Richard Henderson <richard.henderson@...aro.org>
Signed-off-by: Mark Rutland <mark.rutland@....com>
Reviewed-by: Christoffer Dall <christoffer.dall@....com>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Marc Zyngier <marc.zyngier@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: kvmarm@...ts.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@....com>
[kristina: backport to 4.9.y: adjust context]
Signed-off-by: Kristina Martsenko <kristina.martsenko@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/arm64/include/asm/kvm_arm.h | 1 +
 arch/arm64/kernel/head.S         | 5 ++---
 arch/arm64/kvm/hyp/switch.c      | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 68dedca5a47e..352bf2f7f60a 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -82,6 +82,7 @@
 			 HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW)
 #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF)
 #define HCR_INT_OVERRIDE   (HCR_FMO | HCR_IMO)
+#define HCR_HOST_NVHE_FLAGS (HCR_RW)
 #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
 
 /* TCR_EL2 Registers bits */
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index fa52817d84c5..3289d1458791 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -517,10 +517,9 @@ CPU_LE(	bic	x0, x0, #(3 << 24)	)	// Clear the EE and E0E bits for EL1
 #endif
 
 	/* Hyp configuration. */
-	mov	x0, #HCR_RW			// 64-bit EL1
+	mov_q	x0, HCR_HOST_NVHE_FLAGS
 	cbz	x2, set_hcr
-	orr	x0, x0, #HCR_TGE		// Enable Host Extensions
-	orr	x0, x0, #HCR_E2H
+	mov_q	x0, HCR_HOST_VHE_FLAGS
 set_hcr:
 	msr	hcr_el2, x0
 	isb
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 12f9d1ecdf4c..115b0955715f 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -112,7 +112,7 @@ static void __hyp_text __deactivate_traps_vhe(void)
 
 static void __hyp_text __deactivate_traps_nvhe(void)
 {
-	write_sysreg(HCR_RW, hcr_el2);
+	write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2);
 	write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
 }
 
-- 
2.19.1