KVM: arm64: Add a vcpu flag to control ptrauth for guest

A per vcpu flag is added to check if pointer authentication is
enabled for the vcpu or not. This flag may be enabled according to
the necessary user policies and host capabilities.

This patch also adds a helper to check the flag.

Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7a096fdb333d60de86cb6b1bf6ca1f502592f352..7ccac42a91a66eb92d1342b2c75d1b8d3a5215e0 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -355,10 +355,15 @@ struct kvm_vcpu_arch {
 #define KVM_ARM64_HOST_SVE_ENABLED     (1 << 4) /* SVE enabled for EL0 */
 #define KVM_ARM64_GUEST_HAS_SVE                (1 << 5) /* SVE exposed to guest */
 #define KVM_ARM64_VCPU_SVE_FINALIZED   (1 << 6) /* SVE config completed */
+#define KVM_ARM64_GUEST_HAS_PTRAUTH    (1 << 7) /* PTRAUTH exposed to guest */
 
 #define vcpu_has_sve(vcpu) (system_supports_sve() && \
                            ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
 
+#define vcpu_has_ptrauth(vcpu) ((system_supports_address_auth() || \
+                                 system_supports_generic_auth()) && \
+                                ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
+
 #define vcpu_gp_regs(v)                (&(v)->arch.ctxt.gp_regs)
 
 /*