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From: Kristina Martsenko <kristina.martsenko@arm.com>
To: stable@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Will Deacon <will.deacon@arm.com>
Subject: [PATCH 4.4 2/2] arm64: Don't trap host pointer auth use to EL2
Date: Fri, 18 Jan 2019 17:55:54 +0000	[thread overview]
Message-ID: <20190118175554.6359-2-kristina.martsenko@arm.com> (raw)
In-Reply-To: <20190118175554.6359-1-kristina.martsenko@arm.com>

From: Mark Rutland <mark.rutland@arm.com>

[ Backport of upstream commit b3669b1e1c09890d61109a1a8ece2c5b66804714 ]

To allow EL0 (and/or EL1) to use pointer authentication functionality,
we must ensure that pointer authentication instructions and accesses to
pointer authentication keys are not trapped to EL2.

This patch ensures that HCR_EL2 is configured appropriately when the
kernel is booted at EL2. For non-VHE kernels we set HCR_EL2.{API,APK},
ensuring that EL1 can access keys and permit EL0 use of instructions.
For VHE kernels host EL0 (TGE && E2H) is unaffected by these settings,
and it doesn't matter how we configure HCR_EL2.{API,APK}, so we don't
bother setting them.

This does not enable support for KVM guests, since KVM manages HCR_EL2
itself when running VMs.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Will Deacon <will.deacon@arm.com>
[kristina: backport to 4.4.y: adjust context]
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
---
 arch/arm64/include/asm/kvm_arm.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 013b7de45ee7..d7e7cf56e8d6 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -23,6 +23,8 @@
 #include <asm/types.h>
 
 /* Hyp Configuration Register (HCR) bits */
+#define HCR_API		(UL(1) << 41)
+#define HCR_APK		(UL(1) << 40)
 #define HCR_ID		(UL(1) << 33)
 #define HCR_CD		(UL(1) << 32)
 #define HCR_RW_SHIFT	31
@@ -81,7 +83,7 @@
 			 HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW)
 #define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
 #define HCR_INT_OVERRIDE   (HCR_FMO | HCR_IMO)
-#define HCR_HOST_NVHE_FLAGS (HCR_RW)
+#define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK)
 
 
 /* Hyp System Control Register (SCTLR_EL2) bits */
-- 
2.11.0


  reply	other threads:[~2019-01-18 17:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-18 17:53 Two arm64 patches for stable Kristina Martsenko
2019-01-18 17:55 ` [PATCH 4.4 1/2] arm64/kvm: consistently handle host HCR_EL2 flags Kristina Martsenko
2019-01-18 17:55   ` Kristina Martsenko [this message]
2019-01-18 17:56 ` [PATCH 4.9 " Kristina Martsenko
2019-01-18 17:56   ` [PATCH 4.9 2/2] arm64: Don't trap host pointer auth use to EL2 Kristina Martsenko
2019-01-18 17:56 ` [PATCH 4.14 1/2] arm64/kvm: consistently handle host HCR_EL2 flags Kristina Martsenko
2019-01-18 17:56   ` [PATCH 4.14 2/2] arm64: Don't trap host pointer auth use to EL2 Kristina Martsenko
2019-01-19  2:07 ` Two arm64 patches for stable Sasha Levin

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