From: christoffer.dall@arm.com (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv3 04/11] arm64: Don't trap host pointer auth use to EL2
Date: Fri, 27 Apr 2018 11:52:05 +0200 [thread overview]
Message-ID: <20180427095205.GJ13249@C02W217FHV2R.local> (raw)
In-Reply-To: <20180417183735.56985-5-mark.rutland@arm.com>
On Tue, Apr 17, 2018 at 07:37:28PM +0100, Mark Rutland wrote:
> 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.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Christoffer Dall <cdall@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: kvmarm at lists.cs.columbia.edu
FWIW: Acked-by: Christoffer Dall <christoffer.dall@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 89b3dda7e3cb..4d57e1e58323 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_TEA (UL(1) << 37)
> #define HCR_TERR (UL(1) << 36)
> #define HCR_TLOR (UL(1) << 35)
> @@ -86,7 +88,7 @@
> HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \
> HCR_FMO | HCR_IMO)
> #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF)
> -#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 */
> --
> 2.11.0
>
> _______________________________________________
> kvmarm mailing list
> kvmarm at lists.cs.columbia.edu
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply other threads:[~2018-04-27 9:52 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-17 18:37 [PATCHv3 00/11] ARMv8.3 pointer authentication userspace support Mark Rutland
2018-04-17 18:37 ` [PATCHv3 01/11] arm64: add pointer authentication register bits Mark Rutland
2018-04-17 18:37 ` [PATCHv3 02/11] arm64/kvm: consistently handle host HCR_EL2 flags Mark Rutland
2018-04-27 9:51 ` Christoffer Dall
2018-04-27 10:13 ` Mark Rutland
2018-04-17 18:37 ` [PATCHv3 03/11] arm64/kvm: hide ptrauth from guests Mark Rutland
2018-04-18 13:19 ` Andrew Jones
2018-04-18 13:47 ` Mark Rutland
2018-04-27 9:51 ` Christoffer Dall
2018-04-17 18:37 ` [PATCHv3 04/11] arm64: Don't trap host pointer auth use to EL2 Mark Rutland
2018-04-27 9:52 ` Christoffer Dall [this message]
2018-04-17 18:37 ` [PATCHv3 05/11] arm64/cpufeature: detect pointer authentication Mark Rutland
2018-04-17 18:37 ` [PATCHv3 06/11] asm-generic: mm_hooks: allow hooks to be overridden individually Mark Rutland
2018-04-17 19:56 ` Arnd Bergmann
2018-04-18 11:38 ` Mark Rutland
2018-04-17 18:37 ` [PATCHv3 07/11] arm64: add basic pointer authentication support Mark Rutland
2018-04-25 11:23 ` Catalin Marinas
2018-04-27 10:27 ` Mark Rutland
2018-04-17 18:37 ` [PATCHv3 08/11] arm64: expose user PAC bit positions via ptrace Mark Rutland
2018-04-17 18:37 ` [PATCHv3 09/11] arm64: perf: strip PAC when unwinding userspace Mark Rutland
2018-04-17 18:37 ` [PATCHv3 10/11] arm64: enable pointer authentication Mark Rutland
2018-04-17 18:37 ` [PATCHv3 11/11] arm64: docs: document " Mark Rutland
2018-04-22 8:05 ` Pavel Machek
2018-04-22 8:47 ` Marc Zyngier
2018-04-22 9:00 ` Pavel Machek
2018-04-25 12:27 ` Catalin Marinas
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