[PATCH v2 4/5] KVM: arm64: Check HCR_EL2 instead of shadow copy to swap PtrAuth registers

Marc Zyngier maz at kernel.org
Mon Jun 22 04:06:42 EDT 2020


When save/restoring PtrAuth registers between host and guest, it is
pretty useless to fetch the in-memory state, while we have the right
state in the HCR_EL2 system register. Use that instead.

Acked-by: Mark Rutland <mark.rutland at arm.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/kvm_ptrauth.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_ptrauth.h b/arch/arm64/include/asm/kvm_ptrauth.h
index 6301813dcace..f1830173fa9e 100644
--- a/arch/arm64/include/asm/kvm_ptrauth.h
+++ b/arch/arm64/include/asm/kvm_ptrauth.h
@@ -74,7 +74,7 @@ alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
 	b	1001f
 alternative_else_nop_endif
 1000:
-	ldr	\reg1, [\g_ctxt, #(VCPU_HCR_EL2 - VCPU_CONTEXT)]
+	mrs	\reg1, hcr_el2
 	and	\reg1, \reg1, #(HCR_API | HCR_APK)
 	cbz	\reg1, 1001f
 	add	\reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
@@ -90,7 +90,7 @@ alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
 	b	2001f
 alternative_else_nop_endif
 2000:
-	ldr	\reg1, [\g_ctxt, #(VCPU_HCR_EL2 - VCPU_CONTEXT)]
+	mrs	\reg1, hcr_el2
 	and	\reg1, \reg1, #(HCR_API | HCR_APK)
 	cbz	\reg1, 2001f
 	add	\reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
-- 
2.27.0




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