The test checks the behavior of the MSR between L1 and L2. In
particular, the value must be preserved across entry and exit,
even in presence of a TSC offset in the VMCB.
Based on a VMX test by Ken Hofsass.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
x86/svm.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/x86/svm.c b/x86/svm.c
index 162632c..2350911 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -877,6 +877,46 @@ static bool npt_rw_l1mmio_check(struct test *test)
&& (test->vmcb->control.exit_info_1 == 0x100000007ULL);
}
+#define TSC_ADJUST_VALUE (1ll << 32)
+#define TSC_OFFSET_VALUE (-1ll << 48)
+static bool ok;
+
+static void tsc_adjust_prepare(struct test *test)
+{
+ default_prepare(test);
+ test->vmcb->control.tsc_offset = TSC_OFFSET_VALUE;
+
+ wrmsr(MSR_IA32_TSC_ADJUST, -TSC_ADJUST_VALUE);
+ int64_t adjust = rdmsr(MSR_IA32_TSC_ADJUST);
+ ok = adjust == -TSC_ADJUST_VALUE;
+}
+
+static void tsc_adjust_test(struct test *test)
+{
+ int64_t adjust = rdmsr(MSR_IA32_TSC_ADJUST);
+ ok &= adjust == -TSC_ADJUST_VALUE;
+
+ uint64_t l1_tsc = rdtsc() - TSC_OFFSET_VALUE;
+ wrmsr(MSR_IA32_TSC, l1_tsc - TSC_ADJUST_VALUE);
+
+ adjust = rdmsr(MSR_IA32_TSC_ADJUST);
+ ok &= adjust <= -2 * TSC_ADJUST_VALUE;
+
+ uint64_t l1_tsc_end = rdtsc() - TSC_OFFSET_VALUE;
+ ok &= (l1_tsc_end + TSC_ADJUST_VALUE - l1_tsc) < TSC_ADJUST_VALUE;
+
+ uint64_t l1_tsc_msr = rdmsr(MSR_IA32_TSC) - TSC_OFFSET_VALUE;
+ ok &= (l1_tsc_msr + TSC_ADJUST_VALUE - l1_tsc) < TSC_ADJUST_VALUE;
+}
+
+static bool tsc_adjust_check(struct test *test)
+{
+ int64_t adjust = rdmsr(MSR_IA32_TSC_ADJUST);
+
+ wrmsr(MSR_IA32_TSC_ADJUST, 0);
+ return ok && adjust <= -2 * TSC_ADJUST_VALUE;
+}
+
static void latency_prepare(struct test *test)
{
default_prepare(test);
@@ -1048,6 +1088,8 @@ static struct test tests[] = {
default_finished, npt_l1mmio_check },
{ "npt_rw_l1mmio", npt_supported, npt_rw_l1mmio_prepare, npt_rw_l1mmio_test,
default_finished, npt_rw_l1mmio_check },
+ { "tsc_adjust", default_supported, tsc_adjust_prepare, tsc_adjust_test,
+ default_finished, tsc_adjust_check },
{ "latency_run_exit", default_supported, latency_prepare, latency_test,
latency_finished, latency_check },
{ "latency_svm_insn", default_supported, lat_svm_insn_prepare, null_test,
--
2.14.3
