[PATCH v7 02/11] KVM: selftests: Read binary stats header in lib

Ben Gardon
2022-05-03T18:31:00Z

Move the code to read the binary stats header to the KVM selftests
library. It will be re-used by other tests to check KVM behavior.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
---
.../selftests/kvm/include/kvm_util_base.h | 1 +
.../selftests/kvm/kvm_binary_stats_test.c | 4 ++--
tools/testing/selftests/kvm/lib/kvm_util.c | 21 +++++++++++++++++++
3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 92cef0ffb19e..749cded9b157 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -400,6 +400,7 @@ 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 read_stats_header(int stats_fd, struct kvm_stats_header *header);

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 dad34d8a41fe..fb511b42a03e 100644
--- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c
+++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
@@ -33,8 +33,8 @@ static void stats_test(int stats_fd)
struct kvm_stats_desc *pdesc;

/* Read kvm stats header */
- ret = read(stats_fd, &header, sizeof(header));
- TEST_ASSERT(ret == sizeof(header), "Read stats header");
+ read_stats_header(stats_fd, &header);
+
size_desc = sizeof(*stats_desc) + header.name_size;

/* Read kvm stats id string */
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 1665a220abcb..1d75d41f92dc 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2556,3 +2556,24 @@ int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid)

return ioctl(vcpu->fd, KVM_GET_STATS_FD, NULL);
}
+
+/*
+ * Read binary stats header
+ *
+ * Input Args:
+ * stats_fd - the file descriptor for the binary stats file from which to read
+ *
+ * Output Args:
+ * header - a binary stats metadata header to be filled with data
+ *
+ * Return: void
+ *
+ * Read a header for the binary stats interface.
+ */
+void read_stats_header(int stats_fd, struct kvm_stats_header *header)
+{
+ ssize_t ret;
+
+ ret = read(stats_fd, header, sizeof(*header));
+ TEST_ASSERT(ret == sizeof(*header), "Read stats header");
+}
--
2.36.0.464.gb9c8b46e94-goog