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arm64: Don't trap host pointer auth use to EL2

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[ 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 4.14.y: adjust context]
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mark Rutland 2019-01-18 17:56:33 +00:00 committed by Greg Kroah-Hartman
parent 4ef8d21b71
commit fea3f83ee0
1 changed files with 3 additions and 1 deletions
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4
arch/arm64/include/asm/kvm_arm.h
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@ -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_E2H (UL(1) << 34)
#define HCR_ID (UL(1) << 33)
#define HCR_CD (UL(1) << 32)
@ -82,7 +84,7 @@
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_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK)
#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
/* TCR_EL2 Registers bits */