[PATCH v3 5/6] KVM: selftests: Test reading a single stat
From: Mingwei Zhang
Date: Fri Apr 01 2022 - 02:37:36 EST
From: Ben Gardon <bgardon@xxxxxxxxxx>
Retrieve the value of a single stat by name in the binary stats test to
ensure the kvm_util library functions work.
CC: Jing Zhang <jingzhangos@xxxxxxxxxx>
Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
---
.../selftests/kvm/include/kvm_util_base.h | 1 +
.../selftests/kvm/kvm_binary_stats_test.c | 3 ++
tools/testing/selftests/kvm/lib/kvm_util.c | 53 +++++++++++++++++++
3 files changed, 57 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index c5f4a67772cb..09ee70c0df26 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -401,6 +401,7 @@ void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid);
int vm_get_stats_fd(struct kvm_vm *vm);
int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid);
void dump_vm_stats(struct kvm_vm *vm);
+uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name);
uint32_t guest_get_vcpuid(void);
diff --git a/tools/testing/selftests/kvm/kvm_binary_stats_test.c b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
index afc4701ce8dd..97bde355f105 100644
--- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c
+++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
@@ -177,6 +177,9 @@ static void vm_stats_test(struct kvm_vm *vm)
/* Dump VM stats */
dump_vm_stats(vm);
+
+ /* Read a single stat. */
+ printf("remote_tlb_flush: %lu\n", vm_get_single_stat(vm, "remote_tlb_flush"));
}
static void vcpu_stats_test(struct kvm_vm *vm, int vcpu_id)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 4d21c3b46780..1d3493d7fd55 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2699,3 +2699,56 @@ void dump_vm_stats(struct kvm_vm *vm)
close(stats_fd);
}
+static int vm_get_stat_data(struct kvm_vm *vm, const char *stat_name,
+ uint64_t **data)
+{
+ struct kvm_stats_desc *stats_desc;
+ struct kvm_stats_header *header;
+ struct kvm_stats_desc *desc;
+ size_t size_desc;
+ int stats_fd;
+ int ret = -EINVAL;
+ int i;
+
+ *data = NULL;
+
+ stats_fd = vm_get_stats_fd(vm);
+
+ header = read_vm_stats_header(stats_fd);
+
+ stats_desc = read_vm_stats_desc(stats_fd, header);
+
+ size_desc = stats_desc_size(header);
+
+ /* Read kvm stats data one by one */
+ for (i = 0; i < header->num_desc; ++i) {
+ desc = (void *)stats_desc + (i * size_desc);
+
+ if (strcmp(desc->name, stat_name))
+ continue;
+
+ ret = read_stat_data(stats_fd, header, desc, data);
+ }
+
+ free(stats_desc);
+ free(header);
+
+ close(stats_fd);
+
+ return ret;
+}
+
+uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name)
+{
+ uint64_t *data;
+ uint64_t value;
+ int ret;
+
+ ret = vm_get_stat_data(vm, stat_name, &data);
+ TEST_ASSERT(ret == 1, "Stat %s expected to have 1 element, but has %d",
+ stat_name, ret);
+ value = *data;
+ free(data);
+ return value;
+}
+
--
2.35.1.1094.g7c7d902a7c-goog