From: Marc Zyngier <maz@kernel.org>
To: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Cc: James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Andrew Scull <ascull@google.com>,
Dave Martin <Dave.Martin@arm.com>,
kernel-team@android.com
Subject: [PATCH v2 5/5] KVM: arm64: Simplify PtrAuth alternative patching
Date: Mon, 22 Jun 2020 09:06:43 +0100 [thread overview]
Message-ID: <20200622080643.171651-6-maz@kernel.org> (raw)
In-Reply-To: <20200622080643.171651-1-maz@kernel.org>
We currently decide to execute the PtrAuth save/restore code based
on a set of branches that evaluate as (ARM64_HAS_ADDRESS_AUTH_ARCH ||
ARM64_HAS_ADDRESS_AUTH_IMP_DEF). This can be easily replaced by
a much simpler test as the ARM64_HAS_ADDRESS_AUTH capability is
exactly this expression.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_ptrauth.h | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_ptrauth.h b/arch/arm64/include/asm/kvm_ptrauth.h
index f1830173fa9e..7a72508a841b 100644
--- a/arch/arm64/include/asm/kvm_ptrauth.h
+++ b/arch/arm64/include/asm/kvm_ptrauth.h
@@ -61,44 +61,36 @@
/*
* Both ptrauth_switch_to_guest and ptrauth_switch_to_host macros will
- * check for the presence of one of the cpufeature flag
- * ARM64_HAS_ADDRESS_AUTH_ARCH or ARM64_HAS_ADDRESS_AUTH_IMP_DEF and
+ * check for the presence ARM64_HAS_ADDRESS_AUTH, which is defined as
+ * (ARM64_HAS_ADDRESS_AUTH_ARCH || ARM64_HAS_ADDRESS_AUTH_IMP_DEF) and
* then proceed ahead with the save/restore of Pointer Authentication
- * key registers.
+ * key registers if enabled for the guest.
*/
.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3
-alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH
+alternative_if_not ARM64_HAS_ADDRESS_AUTH
b 1000f
alternative_else_nop_endif
-alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
- b 1001f
-alternative_else_nop_endif
-1000:
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
- cbz \reg1, 1001f
+ cbz \reg1, 1000f
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
-1001:
+1000:
.endm
.macro ptrauth_switch_to_host g_ctxt, h_ctxt, reg1, reg2, reg3
-alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH
+alternative_if_not ARM64_HAS_ADDRESS_AUTH
b 2000f
alternative_else_nop_endif
-alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
- b 2001f
-alternative_else_nop_endif
-2000:
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
- cbz \reg1, 2001f
+ cbz \reg1, 2000f
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_save_state \reg1, \reg2, \reg3
add \reg1, \h_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
isb
-2001:
+2000:
.endm
#else /* !CONFIG_ARM64_PTR_AUTH */
--
2.27.0
WARNING: multiple messages have this Message-ID (diff)
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 5/5] KVM: arm64: Simplify PtrAuth alternative patching
Date: Mon, 22 Jun 2020 09:06:43 +0100 [thread overview]
Message-ID: <20200622080643.171651-6-maz@kernel.org> (raw)
In-Reply-To: <20200622080643.171651-1-maz@kernel.org>
We currently decide to execute the PtrAuth save/restore code based
on a set of branches that evaluate as (ARM64_HAS_ADDRESS_AUTH_ARCH ||
ARM64_HAS_ADDRESS_AUTH_IMP_DEF). This can be easily replaced by
a much simpler test as the ARM64_HAS_ADDRESS_AUTH capability is
exactly this expression.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_ptrauth.h | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_ptrauth.h b/arch/arm64/include/asm/kvm_ptrauth.h
index f1830173fa9e..7a72508a841b 100644
--- a/arch/arm64/include/asm/kvm_ptrauth.h
+++ b/arch/arm64/include/asm/kvm_ptrauth.h
@@ -61,44 +61,36 @@
/*
* Both ptrauth_switch_to_guest and ptrauth_switch_to_host macros will
- * check for the presence of one of the cpufeature flag
- * ARM64_HAS_ADDRESS_AUTH_ARCH or ARM64_HAS_ADDRESS_AUTH_IMP_DEF and
+ * check for the presence ARM64_HAS_ADDRESS_AUTH, which is defined as
+ * (ARM64_HAS_ADDRESS_AUTH_ARCH || ARM64_HAS_ADDRESS_AUTH_IMP_DEF) and
* then proceed ahead with the save/restore of Pointer Authentication
- * key registers.
+ * key registers if enabled for the guest.
*/
.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3
-alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH
+alternative_if_not ARM64_HAS_ADDRESS_AUTH
b 1000f
alternative_else_nop_endif
-alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
- b 1001f
-alternative_else_nop_endif
-1000:
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
- cbz \reg1, 1001f
+ cbz \reg1, 1000f
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
-1001:
+1000:
.endm
.macro ptrauth_switch_to_host g_ctxt, h_ctxt, reg1, reg2, reg3
-alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH
+alternative_if_not ARM64_HAS_ADDRESS_AUTH
b 2000f
alternative_else_nop_endif
-alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
- b 2001f
-alternative_else_nop_endif
-2000:
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
- cbz \reg1, 2001f
+ cbz \reg1, 2000f
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_save_state \reg1, \reg2, \reg3
add \reg1, \h_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
isb
-2001:
+2000:
.endm
#else /* !CONFIG_ARM64_PTR_AUTH */
--
2.27.0
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next prev parent reply other threads:[~2020-06-22 8:06 UTC|newest]
Thread overview: 24+ 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 ` 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 8:06 ` Marc Zyngier
2020-06-22 9:04 ` Mark Rutland
2020-06-22 9:04 ` Mark Rutland
2020-06-22 8:06 ` [PATCH v2 2/5] KVM: arm64: Allow ARM64_PTR_AUTH when ARM64_VHE=n Marc Zyngier
2020-06-22 8:06 ` Marc Zyngier
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 ` 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 ` Marc Zyngier
2020-06-22 8:06 ` Marc Zyngier [this message]
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 9:15 ` Mark Rutland
2020-06-22 10:25 ` Marc Zyngier
2020-06-22 10:25 ` Marc Zyngier
2020-06-22 10:31 ` Mark Rutland
2020-06-22 10:31 ` Mark Rutland
2020-06-22 10:39 ` Andrew Scull
2020-06-22 10:39 ` Andrew Scull
2020-06-22 10:43 ` Andrew Scull
2020-06-22 10:43 ` Andrew Scull
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