diff options
author | Ben Gardon <bgardon@google.com> | 2022-06-13 21:25:18 +0000 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-24 04:51:47 -0400 |
commit | ed6b53ec9090133cd744705a09811cf627f3e9cb (patch) | |
tree | e5f65a1520b02f8b2cea0dc792c65a527edfcf2a /tools/testing/selftests/kvm/lib/kvm_util.c | |
parent | KVM: selftests: Clean up coding style in binary stats test (diff) | |
download | linux-dev-ed6b53ec9090133cd744705a09811cf627f3e9cb.tar.xz linux-dev-ed6b53ec9090133cd744705a09811cf627f3e9cb.zip |
KVM: selftests: Read binary stat data in lib
Move the code to read the binary stats data to the KVM selftests
library. It will be re-used by other tests to check KVM behavior.
Also opportunistically remove an unnecessary calculation with
"size_data" in stats_test.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220613212523.3436117-6-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools/testing/selftests/kvm/lib/kvm_util.c')
-rw-r--r-- | tools/testing/selftests/kvm/lib/kvm_util.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 64ef108cc270..e44eb510fcc1 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1883,3 +1883,38 @@ struct kvm_stats_desc *read_stats_descriptors(int stats_fd, return stats_desc; } + +/* + * Read stat data for a particular stat + * + * 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 + * desc - the binary stat metadata for the particular stat to be read + * max_elements - the maximum number of 8-byte values to read into data + * + * Output Args: + * data - the buffer into which stat data should be read + * + * Read the data values of a specified stat from the binary stats interface. + */ +void read_stat_data(int stats_fd, struct kvm_stats_header *header, + struct kvm_stats_desc *desc, uint64_t *data, + size_t max_elements) +{ + size_t nr_elements = min_t(ssize_t, desc->size, max_elements); + size_t size = nr_elements * sizeof(*data); + ssize_t ret; + + TEST_ASSERT(desc->size, "No elements in stat '%s'", desc->name); + TEST_ASSERT(max_elements, "Zero elements requested for stat '%s'", desc->name); + + ret = pread(stats_fd, data, size, + header->data_offset + desc->offset); + + TEST_ASSERT(ret >= 0, "pread() failed on stat '%s', errno: %i (%s)", + desc->name, errno, strerror(errno)); + TEST_ASSERT(ret == size, + "pread() on stat '%s' read %ld bytes, wanted %lu bytes", + desc->name, size, ret); +} |