Hi,
On 4/17/19 2:05 PM, Marc Zyngier wrote:
On 12/04/2019 04:20, Amit Daniel Kachhap wrote:
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.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Christoffer Dall <christoffer.dall@xxxxxxx>
Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx
---
Changes since v8:
* Added a new per vcpu flag which will store Pointer Authentication enable
status instead of checking them again. [Dave Martin]
arch/arm64/include/asm/kvm_host.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 9d57cf8..31dbc7c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -355,10 +355,14 @@ 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) \
+ ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH)
+
Just as for SVE, please first check that the system has PTRAUTH.
Something like:
(cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH_ARCH) && \
((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
In the subsequent patches, vcpu->arch.flags is only set to
KVM_ARM64_GUEST_HAS_PTRAUTH when all host capability check conditions
matches such as system_supports_address_auth(),
system_supports_generic_auth() so doing them again is repetitive in my view.
Thanks,
Amit D
This will save an extra load on unsuspecting CPUs thanks to the static
key embedded in the capability structure.
Thanks,
M.
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
