[Patch 6/6] kvm: tests: Add test to verify MSR_IA32_XSS

Aaron Lewis
2019-10-09T00:42:22Z

Verify that calling get and set for MSR_IA32_XSS returns expected results.

Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
---
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/x86_64/processor.h | 7 +-
.../selftests/kvm/lib/x86_64/processor.c | 69 ++++++++++++++++---
.../selftests/kvm/x86_64/xss_msr_test.c | 65 +++++++++++++++++
5 files changed, 134 insertions(+), 9 deletions(-)
create mode 100644 tools/testing/selftests/kvm/x86_64/xss_msr_test.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index b35da375530a..6e9ec34f8124 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -11,6 +11,7 @@
/x86_64/vmx_close_while_nested_test
/x86_64/vmx_set_nested_state_test
/x86_64/vmx_tsc_adjust_test
+/x86_64/xss_msr_test
/clear_dirty_log_test
/dirty_log_test
/kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index c5ec868fa1e5..3138a916574a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -25,6 +25,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
+TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index ff234018219c..1dc55eea756a 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -308,6 +308,8 @@ struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_x86_state *state);

+struct kvm_msr_list *kvm_get_msr_index_list(void);
+
struct kvm_cpuid2 *kvm_get_supported_cpuid(void);
void vcpu_set_cpuid(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_cpuid2 *cpuid);
@@ -324,8 +326,11 @@ kvm_get_supported_cpuid_entry(uint32_t function)
uint64_t vcpu_get_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index);
void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
uint64_t msr_value);
+void vcpu_set_msr_expect_result(struct kvm_vm *vm, uint32_t vcpuid,
+ uint64_t msr_index, uint64_t msr_value, int result);

-uint32_t kvm_get_cpuid_max(void);
+uint32_t kvm_get_cpuid_max_basic(void);
+uint32_t kvm_get_cpuid_max_extended(void);
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits);

/*
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 6698cb741e10..425262e15afa 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -869,13 +869,14 @@ uint64_t vcpu_get_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index)
return buffer.entry.data;
}

-/* VCPU Set MSR
+/* VCPU Set MSR Expect Result
*
* Input Args:
* vm - Virtual Machine
* vcpuid - VCPU ID
* msr_index - Index of MSR
* msr_value - New value of MSR
+ * result - The expected result of KVM_SET_MSRS
*
* Output Args: None
*
@@ -883,8 +884,9 @@ uint64_t vcpu_get_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index)
*
* Set value of MSR for VCPU.
*/
-void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
- uint64_t msr_value)
+void vcpu_set_msr_expect_result(struct kvm_vm *vm, uint32_t vcpuid,
+ uint64_t msr_index, uint64_t msr_value,
+ int result)
{
struct vcpu *vcpu = vcpu_find(vm, vcpuid);
struct {
@@ -899,10 +901,30 @@ void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
buffer.entry.index = msr_index;
buffer.entry.data = msr_value;
r = ioctl(vcpu->fd, KVM_SET_MSRS, &buffer.header);
- TEST_ASSERT(r == 1, "KVM_SET_MSRS IOCTL failed,\n"
+ TEST_ASSERT(r == result, "KVM_SET_MSRS IOCTL failed,\n"
" rc: %i errno: %i", r, errno);
}

+/* VCPU Set MSR
+ *
+ * Input Args:
+ * vm - Virtual Machine
+ * vcpuid - VCPU ID
+ * msr_index - Index of MSR
+ * msr_value - New value of MSR
+ *
+ * Output Args: None
+ *
+ * Return: On success, nothing. On failure a TEST_ASSERT is produced.
+ *
+ * Set value of MSR for VCPU.
+ */
+void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
+ uint64_t msr_value)
+{
+ vcpu_set_msr_expect_result(vm, vcpuid, msr_index, msr_value, 1);
+}
+
/* VM VCPU Args Set
*
* Input Args:
@@ -1000,19 +1022,45 @@ struct kvm_x86_state {
struct kvm_msrs msrs;
};

-static int kvm_get_num_msrs(struct kvm_vm *vm)
+static int kvm_get_num_msrs_fd(int kvm_fd)
{
struct kvm_msr_list nmsrs;
int r;

nmsrs.nmsrs = 0;
- r = ioctl(vm->kvm_fd, KVM_GET_MSR_INDEX_LIST, &nmsrs);
+ r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, &nmsrs);
TEST_ASSERT(r == -1 && errno == E2BIG, "Unexpected result from KVM_GET_MSR_INDEX_LIST probe, r: %i",
r);

return nmsrs.nmsrs;
}

+static int kvm_get_num_msrs(struct kvm_vm *vm)
+{
+ return kvm_get_num_msrs_fd(vm->kvm_fd);
+}
+
+struct kvm_msr_list *kvm_get_msr_index_list(void)
+{
+ struct kvm_msr_list *list;
+ int nmsrs, r, kvm_fd;
+
+ kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
+ if (kvm_fd < 0)
+ exit(KSFT_SKIP);
+
+ nmsrs = kvm_get_num_msrs_fd(kvm_fd);
+ list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+ list->nmsrs = nmsrs;
+ r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
+ close(kvm_fd);
+
+ TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_MSR_INDEX_LIST, r: %i",
+ r);
+
+ return list;
+}
+
struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
{
struct vcpu *vcpu = vcpu_find(vm, vcpuid);
@@ -1158,7 +1206,12 @@ bool is_intel_cpu(void)
return (ebx == chunk[0] && edx == chunk[1] && ecx == chunk[2]);
}

-uint32_t kvm_get_cpuid_max(void)
+uint32_t kvm_get_cpuid_max_basic(void)
+{
+ return kvm_get_supported_cpuid_entry(0)->eax;
+}
+
+uint32_t kvm_get_cpuid_max_extended(void)
{
return kvm_get_supported_cpuid_entry(0x80000000)->eax;
}
@@ -1169,7 +1222,7 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
bool pae;

/* SDM 4.1.4 */
- if (kvm_get_cpuid_max() < 0x80000008) {
+ if (kvm_get_cpuid_max_extended() < 0x80000008) {
pae = kvm_get_supported_cpuid_entry(1)->edx & (1 << 6);
*pa_bits = pae ? 36 : 32;
*va_bits = 32;
diff --git a/tools/testing/selftests/kvm/x86_64/xss_msr_test.c b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c
new file mode 100644
index 000000000000..47060eff06ce
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/xss_msr_test.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019, Google LLC.
+ *
+ * Tests for the IA32_XSS MSR.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "vmx.h"
+
+#define VCPU_ID 1
+
+#define X86_FEATURE_XSAVES (1<<3)
+
+int main(int argc, char *argv[])
+{
+ struct kvm_cpuid_entry2 *entry;
+ struct kvm_msr_list *list;
+ bool found_xss = false;
+ struct kvm_vm *vm;
+ uint64_t xss_val;
+ int i;
+
+ /* Create VM */
+ vm = vm_create_default(VCPU_ID, 0, 0);
+
+ list = kvm_get_msr_index_list();
+ for (i = 0; i < list->nmsrs; ++i) {
+ if (list->indices[i] == MSR_IA32_XSS) {
+ found_xss = true;
+ break;
+ }
+ }
+
+ if (kvm_get_cpuid_max_basic() < 0xd) {
+ printf("XSAVES is not supported by the CPU.\n");
+ exit(KSFT_SKIP);
+ }
+
+ entry = kvm_get_supported_cpuid_index(0xd, 1);
+ TEST_ASSERT(found_xss == !!(entry->eax & X86_FEATURE_XSAVES),
+ "Support for IA32_XSS and support for XSAVES do not match.\n");
+
+ if (!found_xss) {
+ printf("IA32_XSS and XSAVES are not supported. Skipping test.\n");
+ exit(KSFT_SKIP);
+ }
+
+ xss_val = vcpu_get_msr(vm, VCPU_ID, MSR_IA32_XSS);
+ TEST_ASSERT(xss_val == 0, "MSR_IA32_XSS should always be zero\n");
+
+ vcpu_set_msr(vm, VCPU_ID, MSR_IA32_XSS, xss_val);
+ /*
+ * At present, KVM only supports a guest IA32_XSS value of 0. Verify
+ * that trying to set the guest IA32_XSS to an unsupported value fails.
+ */
+ vcpu_set_msr_expect_result(vm, VCPU_ID, MSR_IA32_XSS, ~0ull, 0);
+
+ free(list);
+ kvm_vm_free(vm);
+}
--
2.23.0.581.g78d2f28ef7-goog