[PATCH v6 4/4] x86/tests: Add tests for AMD SEV-ES #VC handling Add KUnit based tests to validate Linux's VC handling for IO instructions. 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 issuing an IO instruction. 3. check that the kretprobe was hit with the right exit_code available in GHCB.

Vasant Karasulli
2022-03-18T09:45:52Z

Signed-off-by: Vasant Karasulli <vkarasulli@suse.de>
---
arch/x86/tests/sev-test-vc.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/arch/x86/tests/sev-test-vc.c b/arch/x86/tests/sev-test-vc.c
index b27b9f114a12..d0e742e2bf9f 100644
--- a/arch/x86/tests/sev-test-vc.c
+++ b/arch/x86/tests/sev-test-vc.c
@@ -8,7 +8,9 @@
#include <asm/cpufeature.h>
#include <asm/sev-common.h>
#include <asm/debugreg.h>
+#include <asm/io.h>
#include <asm/svm.h>
+#include <asm/apicdef.h>
#include <kunit/test.h>
#include <linux/kprobes.h>

@@ -111,11 +113,36 @@ static void sev_es_nae_dr7_rw(struct kunit *test)
native_set_debugreg(7, native_get_debugreg(7)));
}

+static void sev_es_nae_ioio(struct kunit *test)
+{
+ unsigned long port = 0x80;
+ char val = 0;
+
+ check_op(test, SVM_EXIT_IOIO, val = inb(port));
+ check_op(test, SVM_EXIT_IOIO, outb(val, port));
+ check_op(test, SVM_EXIT_IOIO, insb(port, &val, sizeof(val)));
+ check_op(test, SVM_EXIT_IOIO, outsb(port, &val, sizeof(val)));
+}
+
+static void sev_es_nae_mmio(struct kunit *test)
+{
+ unsigned long lapic_ver_pa = APIC_DEFAULT_PHYS_BASE + APIC_LVR;
+ unsigned long __iomem *lapic = ioremap(lapic_ver_pa, 0x4);
+ unsigned long lapic_version = 0;
+
+ check_op(test, SVM_VMGEXIT_MMIO_READ, lapic_version = *lapic);
+ check_op(test, SVM_VMGEXIT_MMIO_WRITE, *lapic = lapic_version);
+
+ iounmap(lapic);
+}
+
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),
+ KUNIT_CASE(sev_es_nae_ioio),
+ KUNIT_CASE(sev_es_nae_mmio),
{}
};

--
2.32.0