Move the code to read the binary stats descriptors 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@xxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
---
.../selftests/kvm/include/kvm_util_base.h | 24 ++++++++++++++
.../selftests/kvm/kvm_binary_stats_test.c | 16 +++------
tools/testing/selftests/kvm/lib/kvm_util.c | 33 +++++++++++++++++++
3 files changed, 62 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 749cded9b157..da7bf881f94f 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -401,6 +401,30 @@ 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);
+struct kvm_stats_desc *read_stats_descriptors(int stats_fd,
+ struct kvm_stats_header *header);
+
+static inline ssize_t get_stats_descriptor_size(struct kvm_stats_header *header)
+{
+ /*
+ * The base size of the descriptor is defined by KVM's ABI, but the
+ * size of the name field is variable, as far as KVM's ABI is
+ * concerned. For a given instance of KVM, the name field is the same
+ * size for all stats and is provided in the overall stats header.
+ */
+ return sizeof(struct kvm_stats_desc) + header->name_size;
+}
+
+static inline struct kvm_stats_desc *get_stats_descriptor(struct kvm_stats_desc *stats,
+ int index,
+ struct kvm_stats_header *header)
+{
+ /*
+ * Note, size_desc includes the size of the name field, which is
+ * variable. i.e. this is NOT equivalent to &stats_desc[i].
+ */
+ return (void *)stats + index * get_stats_descriptor_size(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 fb511b42a03e..a5198b9a19c1 100644
--- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c
+++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
@@ -35,7 +35,7 @@ static void stats_test(int stats_fd)
/* Read kvm stats header */
read_stats_header(stats_fd, &header);
- size_desc = sizeof(*stats_desc) + header.name_size;
+ size_desc = get_stats_descriptor_size(&header);
/* Read kvm stats id string */
id = malloc(header.name_size);
@@ -62,18 +62,12 @@ static void stats_test(int stats_fd)
header.data_offset),
"Descriptor block is overlapped with data block");
- /* Allocate memory for stats descriptors */
- stats_desc = calloc(header.num_desc, size_desc);
- TEST_ASSERT(stats_desc, "Allocate memory for stats descriptors");
/* Read kvm stats descriptors */
- ret = pread(stats_fd, stats_desc,
- size_desc * header.num_desc, header.desc_offset);
- TEST_ASSERT(ret == size_desc * header.num_desc,
- "Read KVM stats descriptors");
+ stats_desc = read_stats_descriptors(stats_fd, &header);
/* Sanity check for fields in descriptors */
for (i = 0; i < header.num_desc; ++i) {
- pdesc = (void *)stats_desc + i * size_desc;
+ pdesc = get_stats_descriptor(stats_desc, i, &header);
/* Check type,unit,base boundaries */
TEST_ASSERT((pdesc->flags & KVM_STATS_TYPE_MASK)
<= KVM_STATS_TYPE_MAX, "Unknown KVM stats type");
@@ -129,7 +123,7 @@ static void stats_test(int stats_fd)
"Data size is not correct");
/* Check stats offset */
for (i = 0; i < header.num_desc; ++i) {
- pdesc = (void *)stats_desc + i * size_desc;
+ pdesc = get_stats_descriptor(stats_desc, i, &header);
TEST_ASSERT(pdesc->offset < size_data,
"Invalid offset (%u) for stats: %s",
pdesc->offset, pdesc->name);
@@ -144,7 +138,7 @@ static void stats_test(int stats_fd)
/* Read kvm stats data one by one */
size_data = 0;
for (i = 0; i < header.num_desc; ++i) {
- pdesc = (void *)stats_desc + i * size_desc;
+ pdesc = get_stats_descriptor(stats_desc, i, &header);
ret = pread(stats_fd, stats_data,
pdesc->size * sizeof(*stats_data),
header.data_offset + size_data);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 1d75d41f92dc..e5abcb189f1d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2577,3 +2577,36 @@ void read_stats_header(int stats_fd, struct kvm_stats_header *header)
ret = read(stats_fd, header, sizeof(*header));
TEST_ASSERT(ret == sizeof(*header), "Read stats header");
}
+
+/*
+ * Read binary stats descriptors
+ *
+ * Input Args:
+ * stats_fd - the file descriptor for the binary stats file from which to read
+ * header - the binary stats metadata header corresponding to the given FD
+ *
+ * Output Args: None
+ *
+ * Return:
+ * A pointer to a newly allocated series of stat descriptors.
+ * Caller is responsible for freeing the returned kvm_stats_desc.
+ *
+ * Read the stats descriptors from the binary stats interface.
+ */
+struct kvm_stats_desc *read_stats_descriptors(int stats_fd,
+ struct kvm_stats_header *header)
+{
+ struct kvm_stats_desc *stats_desc;
+ ssize_t desc_size, total_size, ret;
+
+ desc_size = get_stats_descriptor_size(header);
+ total_size = header->num_desc * desc_size;
+
+ stats_desc = calloc(header->num_desc, desc_size);
+ TEST_ASSERT(stats_desc, "Allocate memory for stats descriptors");
+
+ ret = pread(stats_fd, stats_desc, total_size, header->desc_offset);
+ TEST_ASSERT(ret == total_size, "Read KVM stats descriptors");
+
+ return stats_desc;
+}
--
2.36.1.124.g0e6072fb45-goog
