From: Marc Zyngier <maz@kernel.org>
To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Cc: kernel-team@android.com, Dave Martin <Dave.Martin@arm.com>
Subject: [PATCH v2 2/5] KVM: arm64: Allow ARM64_PTR_AUTH when ARM64_VHE=n
Date: Mon, 22 Jun 2020 09:06:40 +0100 [thread overview]
Message-ID: <20200622080643.171651-3-maz@kernel.org> (raw)
In-Reply-To: <20200622080643.171651-1-maz@kernel.org>
We currently prevent PtrAuth from even being built if KVM is selected,
but VHE isn't. It is a bit of a pointless restriction, since we also
check this at run time (rejecting the enabling of PtrAuth for the
vcpu if we're not running with VHE).
Just drop this apparently useless restriction.
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/Kconfig | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 31380da53689..d719ea9c596d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1516,7 +1516,6 @@ menu "ARMv8.3 architectural features"
config ARM64_PTR_AUTH
bool "Enable support for pointer authentication"
default y
- depends on !KVM || ARM64_VHE
depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
# GCC 9.1 and later inserts a .note.gnu.property section note for PAC
# which is only understood by binutils starting with version 2.33.1.
@@ -1543,8 +1542,7 @@ config ARM64_PTR_AUTH
The feature is detected at runtime. If the feature is not present in
hardware it will not be advertised to userspace/KVM guest nor will it
- be enabled. However, KVM guest also require VHE mode and hence
- CONFIG_ARM64_VHE=y option to use this feature.
+ be enabled.
If the feature is present on the boot CPU but not on a late CPU, then
the late CPU will be parked. Also, if the boot CPU does not have
--
2.27.0
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next prev parent reply other threads:[~2020-06-22 8:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-22 8:06 [PATCH v2 0/5] KVM/arm64: Enable PtrAuth on non-VHE KVM Marc Zyngier
2020-06-22 8:06 ` [PATCH v2 1/5] KVM: arm64: Enable Address Authentication at EL2 if available Marc Zyngier
2020-06-22 9:04 ` Mark Rutland
2020-06-22 8:06 ` Marc Zyngier [this message]
2020-06-22 8:06 ` [PATCH v2 3/5] KVM: arm64: Allow PtrAuth to be enabled from userspace on non-VHE systems Marc Zyngier
2020-06-22 8:06 ` [PATCH v2 4/5] KVM: arm64: Check HCR_EL2 instead of shadow copy to swap PtrAuth registers Marc Zyngier
2020-06-22 8:06 ` [PATCH v2 5/5] KVM: arm64: Simplify PtrAuth alternative patching Marc Zyngier
2020-06-22 9:15 ` Mark Rutland
2020-06-22 10:25 ` Marc Zyngier
2020-06-22 10:31 ` Mark Rutland
2020-06-22 10:39 ` Andrew Scull
2020-06-22 10:43 ` Andrew Scull
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