[kvm-unit-tests RFC 16/16] x86 AMD SEV-ES: Add test cases

[Zixuan Wang <zixuanwang@google.com>]

SEV-ES introduces #VC handler for guest/host communications, e.g.,
accessing MSR, executing CPUID. This commit provides test cases to check
if SEV-ES is enabled and if rdmsr/wrmsr are handled correctly in SEV-ES.

Signed-off-by: Zixuan Wang <zixuanwang@google.com>
---
 x86/amd_sev.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/x86/amd_sev.c b/x86/amd_sev.c
index a07a48f..660196e 100644
--- a/x86/amd_sev.c
+++ b/x86/amd_sev.c
@@ -13,6 +13,7 @@
 #include "libcflat.h"
 #include "x86/processor.h"
 #include "x86/amd_sev.h"
+#include "msr.h"
 
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
@@ -55,10 +56,42 @@ static int test_sev_activation(void)
 	return EXIT_SUCCESS;
 }
 
+#ifdef CONFIG_AMD_SEV_ES
+static int test_sev_es_activation(void)
+{
+	if (!(rdmsr(MSR_SEV_STATUS) & SEV_ES_ENABLED_MASK)) {
+		return EXIT_FAILURE;
+	}
+
+	return EXIT_SUCCESS;
+}
+
+static int test_sev_es_msr(void)
+{
+	/* With SEV-ES, rdmsr/wrmsr trigger #VC exception. If #VC is handled
+	 * correctly, rdmsr/wrmsr should work like without SEV-ES and not crash
+	 * the guest VM.
+	 */
+	u64 val = 0x1234;
+	wrmsr(MSR_TSC_AUX, val);
+	if(val != rdmsr(MSR_TSC_AUX)) {
+		return EXIT_FAILURE;
+	}
+
+	return EXIT_SUCCESS;
+}
+#endif /* CONFIG_AMD_SEV_ES */
+
 int main(void)
 {
 	int rtn;
 	rtn = test_sev_activation();
 	report(rtn == EXIT_SUCCESS, "SEV activation test.");
+#ifdef CONFIG_AMD_SEV_ES
+	rtn = test_sev_es_activation();
+	report(rtn == EXIT_SUCCESS, "SEV-ES activation test.");
+	rtn = test_sev_es_msr();
+	report(rtn == EXIT_SUCCESS, "SEV-ES MSR test.");
+#endif /* CONFIG_AMD_SEV_ES */
 	return report_summary();
 }
-- 
2.33.0.rc1.237.g0d66db33f3-goog