[PATCH v6 3/4] x86/tests: Add tests for AMD SEV-ES #VC handling Add KUnit based tests to validate Linux's VC handling for instructions accessing registers such as MSR and DR7. These tests: 1. install a kretprobe on the #VC handler (sev_es_ghcb_hv_call, to access GHCB before/after the resulting VMGEXIT). 2. trigger an NAE by accessing either MSR or DR7. 3. check that the kretprobe was hit with the right exit_code available in GHCB.

Vasant Karasulli
2022-03-18T09:45:46Z

Signed-off-by: Vasant Karasulli <vkarasulli@suse.de>
---
arch/x86/tests/sev-test-vc.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/arch/x86/tests/sev-test-vc.c b/arch/x86/tests/sev-test-vc.c
index 9d415b9708dc..b27b9f114a12 100644
--- a/arch/x86/tests/sev-test-vc.c
+++ b/arch/x86/tests/sev-test-vc.c
@@ -7,6 +7,7 @@

#include <asm/cpufeature.h>
#include <asm/sev-common.h>
+#include <asm/debugreg.h>
#include <asm/svm.h>
#include <kunit/test.h>
#include <linux/kprobes.h>
@@ -99,9 +100,22 @@ static void sev_es_nae_wbinvd(struct kunit *test)
check_op(test, SVM_EXIT_WBINVD, wbinvd());
}

+static void sev_es_nae_msr(struct kunit *test)
+{
+ check_op(test, SVM_EXIT_MSR, __rdmsr(MSR_IA32_TSC));
+}
+
+static void sev_es_nae_dr7_rw(struct kunit *test)
+{
+ check_op(test, SVM_EXIT_WRITE_DR7,
+ native_set_debugreg(7, native_get_debugreg(7)));
+}
+
static struct kunit_case sev_es_vc_testcases[] = {
KUNIT_CASE(sev_es_nae_cpuid),
KUNIT_CASE(sev_es_nae_wbinvd),
+ KUNIT_CASE(sev_es_nae_msr),
+ KUNIT_CASE(sev_es_nae_dr7_rw),
{}
};

--
2.32.0