selftests: kvm: add get_msr_index_features

Test the KVM_GET_MSR_FEATURE_INDEX_LIST
and KVM_GET_MSR_INDEX_LIST ioctls.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210318145629.486450-1-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/.gitignore

@@ -8,6 +8,7 @@
 /x86_64/debug_regs
 /x86_64/evmcs_test
 /x86_64/get_cpuid_test
+/x86_64/get_msr_index_features
 /x86_64/kvm_pv_test
 /x86_64/hyperv_clock
 /x86_64/hyperv_cpuid

tools/testing/selftests/kvm/Makefile

@@ -39,6 +39,7 @@ LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
 
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
+TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/get_cpuid_test
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock

tools/testing/selftests/kvm/include/kvm_util.h

@@ -16,6 +16,7 @@
 
 #include "sparsebit.h"
 
+#define KVM_DEV_PATH "/dev/kvm"
 #define KVM_MAX_VCPUS 512
 
 /*

tools/testing/selftests/kvm/lib/kvm_util_internal.h

@@ -10,8 +10,6 @@
 
 #include "sparsebit.h"
 
-#define KVM_DEV_PATH		"/dev/kvm"
-
 struct userspace_mem_region {
 	struct kvm_userspace_memory_region region;
 	struct sparsebit *unused_phy_pages;

tools/testing/selftests/kvm/x86_64/get_msr_index_features.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test that KVM_GET_MSR_INDEX_LIST and
+ * KVM_GET_MSR_FEATURE_INDEX_LIST work as intended
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+static int kvm_num_index_msrs(int kvm_fd, int nmsrs)
+{
+	struct kvm_msr_list *list;
+	int r;
+
+	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+	list->nmsrs = nmsrs;
+	r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
+	TEST_ASSERT(r == -1 && errno == E2BIG,
+				"Unexpected result from KVM_GET_MSR_INDEX_LIST probe, r: %i",
+				r);
+
+	r = list->nmsrs;
+	free(list);
+	return r;
+}
+
+static void test_get_msr_index(void)
+{
+	int old_res, res, kvm_fd, r;
+	struct kvm_msr_list *list;
+
+	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
+	if (kvm_fd < 0)
+		exit(KSFT_SKIP);
+
+	old_res = kvm_num_index_msrs(kvm_fd, 0);
+	TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");
+
+	if (old_res != 1) {
+		res = kvm_num_index_msrs(kvm_fd, 1);
+		TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1");
+		TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical");
+	}
+
+	list = malloc(sizeof(*list) + old_res * sizeof(list->indices[0]));
+	list->nmsrs = old_res;
+	r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
+
+	TEST_ASSERT(r == 0,
+		    "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST, r: %i",
+		    r);
+	TEST_ASSERT(list->nmsrs == old_res, "Expecting nmsrs to be identical");
+	free(list);
+
+	close(kvm_fd);
+}
+
+static int kvm_num_feature_msrs(int kvm_fd, int nmsrs)
+{
+	struct kvm_msr_list *list;
+	int r;
+
+	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+	list->nmsrs = nmsrs;
+	r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list);
+	TEST_ASSERT(r == -1 && errno == E2BIG,
+		"Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST probe, r: %i",
+				r);
+
+	r = list->nmsrs;
+	free(list);
+	return r;
+}
+
+struct kvm_msr_list *kvm_get_msr_feature_list(int kvm_fd, int nmsrs)
+{
+	struct kvm_msr_list *list;
+	int r;
+
+	list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+	list->nmsrs = nmsrs;
+	r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list);
+
+	TEST_ASSERT(r == 0,
+		"Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST, r: %i",
+		r);
+
+	return list;
+}
+
+static void test_get_msr_feature(void)
+{
+	int res, old_res, i, kvm_fd;
+	struct kvm_msr_list *feature_list;
+
+	kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
+	if (kvm_fd < 0)
+		exit(KSFT_SKIP);
+
+	old_res = kvm_num_feature_msrs(kvm_fd, 0);
+	TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");
+
+	if (old_res != 1) {
+		res = kvm_num_feature_msrs(kvm_fd, 1);
+		TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1");
+		TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical");
+	}
+
+	feature_list = kvm_get_msr_feature_list(kvm_fd, old_res);
+	TEST_ASSERT(old_res == feature_list->nmsrs,
+				"Unmatching number of msr indexes");
+
+	for (i = 0; i < feature_list->nmsrs; i++)
+		kvm_get_feature_msr(feature_list->indices[i]);
+
+	free(feature_list);
+	close(kvm_fd);
+}
+
+int main(int argc, char *argv[])
+{
+	if (kvm_check_cap(KVM_CAP_GET_MSR_FEATURES))
+		test_get_msr_feature();
+
+	test_get_msr_index();
+}