[RFC PATCH 4/4] KVM: selftests: Add selftest for KVM binary form statistics interface

[Jing Zhang <jingzhangos@google.com>]

Check if the KVM binary form statistics works correctly and whether the
statistics name strings are synced correctly with KVM internal stats
data.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 tools/testing/selftests/kvm/.gitignore        |  1 +
 tools/testing/selftests/kvm/Makefile          |  3 +
 .../selftests/kvm/kvm_bin_form_stats.c        | 89 +++++++++++++++++++
 3 files changed, 93 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/kvm_bin_form_stats.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 32b87cc77c8e..0c8241bd9a17 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -38,3 +38,4 @@
 /memslot_modification_stress_test
 /set_memory_region_test
 /steal_time
+/kvm_bin_form_stats
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index a6d61f451f88..5cdd52ccedf2 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -72,6 +72,7 @@ TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
 TEST_GEN_PROGS_x86_64 += memslot_modification_stress_test
 TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
+TEST_GEN_PROGS_x86_64 += kvm_bin_form_stats
 
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list-sve
@@ -81,6 +82,7 @@ TEST_GEN_PROGS_aarch64 += dirty_log_perf_test
 TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
 TEST_GEN_PROGS_aarch64 += set_memory_region_test
 TEST_GEN_PROGS_aarch64 += steal_time
+TEST_GEN_PROGS_aarch64 += kvm_bin_form_stats
 
 TEST_GEN_PROGS_s390x = s390x/memop
 TEST_GEN_PROGS_s390x += s390x/resets
@@ -89,6 +91,7 @@ TEST_GEN_PROGS_s390x += demand_paging_test
 TEST_GEN_PROGS_s390x += dirty_log_test
 TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
 TEST_GEN_PROGS_s390x += set_memory_region_test
+TEST_GEN_PROGS_s390x += kvm_bin_form_stats
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
diff --git a/tools/testing/selftests/kvm/kvm_bin_form_stats.c b/tools/testing/selftests/kvm/kvm_bin_form_stats.c
new file mode 100644
index 000000000000..36cf206470b1
--- /dev/null
+++ b/tools/testing/selftests/kvm/kvm_bin_form_stats.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kvm_bin_form_stats
+ *
+ * Copyright (C) 2021, Google LLC.
+ *
+ * Test for fd-based IOCTL commands for retrieving KVM statistics data in
+ * binary form. KVM_CAP_STATS_BINARY_FORM, KVM_STATS_GET_INFO,
+ * KVM_STATS_GET_NAMES and KVM_STATS_GET_DATA are checked.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+#include "asm/kvm.h"
+#include "linux/kvm.h"
+
+int main(int argc, char *argv[])
+{
+	struct kvm_stats_info stats_info = {0};
+	struct kvm_stats_names *stats_names;
+	struct kvm_stats_data *stats_data;
+	struct kvm_vm *kvm;
+	int i, ret;
+
+	kvm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
+
+	ret = kvm_check_cap(KVM_CAP_STATS_BINARY_FORM);
+	if (ret < 0) {
+		pr_info("Binary form statistics interface is not supported!\n");
+		goto out_free_kvm;
+	}
+
+	ret = -1;
+	vm_ioctl(kvm, KVM_STATS_GET_INFO, &stats_info);
+	if (stats_info.num_stats == 0) {
+		pr_info("KVM_STATS_GET_INFO failed!\n");
+		pr_info("Or the number of stistics data is zero.\n");
+		goto out_free_kvm;
+	}
+
+	/* Allocate memory for stats name strings and value */
+	stats_names = malloc(sizeof(*stats_names) +
+			stats_info.num_stats * KVM_STATS_NAME_LEN);
+	if (!stats_names) {
+		pr_info("Memory allocation failed!\n");
+		goto out_free_kvm;
+	}
+
+	stats_data = malloc(sizeof(*stats_data) +
+				stats_info.num_stats * sizeof(__u64));
+	if (!stats_data) {
+		pr_info("Memory allocation failed!\n");
+		goto out_free_names;
+	}
+
+	/* Retrieve the name strings and data */
+	stats_names->size = stats_info.num_stats * KVM_STATS_NAME_LEN;
+	vm_ioctl(kvm, KVM_STATS_GET_NAMES, stats_names);
+
+	stats_data->size = stats_info.num_stats * sizeof(__u64);
+	vm_ioctl(kvm, KVM_STATS_GET_DATA, stats_data);
+
+	/* Display supported statistics names */
+	for (i = 0; i < (int)stats_info.num_stats; i++) {
+		char *name = (char *)stats_names->names + i * KVM_STATS_NAME_LEN;
+
+		if (strnlen(name, KVM_STATS_NAME_LEN) == 0) {
+			pr_info("Empty stats name at offset %d!\n", i);
+			goto out_free_data;
+		}
+		pr_info("%s\n", name);
+	}
+
+	ret = 0;
+out_free_data:
+	free(stats_data);
+out_free_names:
+	free(stats_names);
+out_free_kvm:
+	kvm_vm_free(kvm);
+	return ret;
+}
-- 
2.30.1.766.gb4fecdf3b7-goog