[TEST PATCH] KVM: selftests: Add a test case for debugfs directory

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

Along with testing the binary interface for KVM statistics, it's good to
do a small sanity check of the KVM debugfs interface. So, add a test case
to the existing kvm_binary_stats_test.c to check that KVM debugfs contains
the correct directory entries for the test VMs and test VCPUs. Also,
rename the file to kvm_stats_test.c.

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
---
 tools/testing/selftests/kvm/Makefile          |  6 ++--
 .../testing/selftests/kvm/include/test_util.h |  2 ++
 ...m_binary_stats_test.c => kvm_stats_test.c} | 31 +++++++++++++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)
 rename tools/testing/selftests/kvm/{kvm_binary_stats_test.c => kvm_stats_test.c} (88%)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 5832f510a16c..673e1f6d20f4 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -82,7 +82,7 @@ TEST_GEN_PROGS_x86_64 += memslot_modification_stress_test
 TEST_GEN_PROGS_x86_64 += memslot_perf_test
 TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
-TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
+TEST_GEN_PROGS_x86_64 += kvm_stats_test
 
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
@@ -94,7 +94,7 @@ TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
 TEST_GEN_PROGS_aarch64 += kvm_page_table_test
 TEST_GEN_PROGS_aarch64 += set_memory_region_test
 TEST_GEN_PROGS_aarch64 += steal_time
-TEST_GEN_PROGS_aarch64 += kvm_binary_stats_test
+TEST_GEN_PROGS_aarch64 += kvm_stats_test
 
 TEST_GEN_PROGS_s390x = s390x/memop
 TEST_GEN_PROGS_s390x += s390x/resets
@@ -104,7 +104,7 @@ TEST_GEN_PROGS_s390x += dirty_log_test
 TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
 TEST_GEN_PROGS_s390x += kvm_page_table_test
 TEST_GEN_PROGS_s390x += set_memory_region_test
-TEST_GEN_PROGS_s390x += kvm_binary_stats_test
+TEST_GEN_PROGS_s390x += kvm_stats_test
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
index d79be15dd3d2..812be7b67c2d 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -59,6 +59,8 @@ void test_assert(bool exp, const char *exp_str,
 #define TEST_FAIL(fmt, ...) \
 	TEST_ASSERT(false, fmt, ##__VA_ARGS__)
 
+#define	KVM_DEBUGFS_PATH	"/sys/kernel/debug/kvm"
+
 size_t parse_size(const char *size);
 
 int64_t timespec_to_ns(struct timespec ts);
diff --git a/tools/testing/selftests/kvm/kvm_binary_stats_test.c b/tools/testing/selftests/kvm/kvm_stats_test.c
similarity index 88%
rename from tools/testing/selftests/kvm/kvm_binary_stats_test.c
rename to tools/testing/selftests/kvm/kvm_stats_test.c
index 5906bbc08483..4b73e7d5ac0f 100644
--- a/tools/testing/selftests/kvm/kvm_binary_stats_test.c
+++ b/tools/testing/selftests/kvm/kvm_stats_test.c
@@ -13,6 +13,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/stat.h>
 
 #include "test_util.h"
 
@@ -179,6 +180,7 @@ static void vcpu_stats_test(struct kvm_vm *vm, int vcpu_id)
 
 #define DEFAULT_NUM_VM		4
 #define DEFAULT_NUM_VCPU	4
+#define	INT_MAX_LEN		10
 
 /*
  * Usage: kvm_bin_form_stats [#vm] [#vcpu]
@@ -230,8 +232,37 @@ int main(int argc, char *argv[])
 			vcpu_stats_test(vms[i], j);
 	}
 
+	/*
+	 * Check debugfs directory for every VM and VCPU
+	 */
+	struct stat buf;
+	int len;
+	char *vm_dir_path = NULL;
+	char *vcpu_dir_path = NULL;
+
+	len = strlen(KVM_DEBUGFS_PATH) + 2 * INT_MAX_LEN + 3;
+	vm_dir_path = malloc(len);
+	TEST_ASSERT(vm_dir_path, "Allocate memory for VM directory path");
+	vcpu_dir_path = malloc(len + INT_MAX_LEN + 6);
+	TEST_ASSERT(vm_dir_path, "Allocate memory for VCPU directory path");
+	for (i = 0; i < max_vm; ++i) {
+		sprintf(vm_dir_path, "%s/%d-%d", KVM_DEBUGFS_PATH, getpid(),
+			vm_get_fd(vms[i]));
+		stat(vm_dir_path, &buf);
+		TEST_ASSERT(S_ISDIR(buf.st_mode), "VM directory %s does not exist",
+			    vm_dir_path);
+		for (j = 0; j < max_vcpu; ++j) {
+			sprintf(vcpu_dir_path, "%s/vcpu%d", vm_dir_path, j);
+			stat(vcpu_dir_path, &buf);
+			TEST_ASSERT(S_ISDIR(buf.st_mode), "VCPU directory %s does not exist",
+				    vcpu_dir_path);
+		}
+	}
+
 	for (i = 0; i < max_vm; ++i)
 		kvm_vm_free(vms[i]);
 	free(vms);
+	free(vm_dir_path);
+	free(vcpu_dir_path);
 	return 0;
 }
-- 
2.27.0