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

Marc Zyngier
2020-06-15T08:20:14Z

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.

Signed-off-by: Marc Zyngier <maz@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