[PATCH 5/6] Add is_sev_enabled() helpers

[Peter Gonda <pgonda@google.com>]

Add helper functions for guest code to check the status of SEV and
SEV-ES.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Carlos Bilbao <carlos.bilbao@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Signed-off-by: Peter Gonda <pgonda@google.com>
---
 tools/testing/selftests/kvm/include/x86_64/sev.h    |  3 +++
 tools/testing/selftests/kvm/lib/x86_64/sev.c        | 11 +++++++++++
 tools/testing/selftests/kvm/x86_64/sev_smoke_test.c |  5 ++---
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86_64/sev.h b/tools/testing/selftests/kvm/include/x86_64/sev.h
index bfd481707f67..691dc005e2a1 100644
--- a/tools/testing/selftests/kvm/include/x86_64/sev.h
+++ b/tools/testing/selftests/kvm/include/x86_64/sev.h
@@ -106,4 +106,7 @@ static inline void sev_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa,
 	vm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_DATA, &update_data);
 }
 
+bool is_sev_enabled(void);
+bool is_sev_es_enabled(void);
+
 #endif /* SELFTEST_KVM_SEV_H */
diff --git a/tools/testing/selftests/kvm/lib/x86_64/sev.c b/tools/testing/selftests/kvm/lib/x86_64/sev.c
index 27ae1d3b1355..5b3f0a8a931a 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/sev.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/sev.c
@@ -189,3 +189,14 @@ struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t policy, void *guest_code,
 
 	return vm;
 }
+
+bool is_sev_enabled(void)
+{
+	return rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED;
+}
+
+bool is_sev_es_enabled(void)
+{
+	return is_sev_enabled() &&
+	       rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ES_ENABLED;
+}
diff --git a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
index 026779f3ed06..1d84e78e7ae2 100644
--- a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
@@ -16,8 +16,7 @@
 static void guest_sev_es_code(void)
 {
 	/* TODO: Check CPUID after GHCB-based hypercall support is added. */
-	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
-	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ES_ENABLED);
+	GUEST_ASSERT(is_sev_es_enabled());
 
 	/*
 	 * TODO: Add GHCB and ucall support for SEV-ES guests.  For now, simply
@@ -30,7 +29,7 @@ static void guest_sev_es_code(void)
 static void guest_sev_code(void)
 {
 	GUEST_ASSERT(this_cpu_has(X86_FEATURE_SEV));
-	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
+	GUEST_ASSERT(is_sev_enabled());
 
 	GUEST_DONE();
 }
-- 
2.44.0.478.gd926399ef9-goog