diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h
index 112bc1d..ce33d30 100644
--- a/tools/testing/selftests/kvm/include/ucall_common.h
+++ b/tools/testing/selftests/kvm/include/ucall_common.h
@@ -1,7 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * tools/testing/selftests/kvm/include/kvm_util.h
- *
  * Copyright (C) 2018, Google LLC.
  */
 #ifndef SELFTEST_KVM_UCALL_COMMON_H
diff --git a/tools/testing/selftests/kvm/lib/guest_sprintf.c b/tools/testing/selftests/kvm/lib/guest_sprintf.c
index c4a69d8..7462751 100644
--- a/tools/testing/selftests/kvm/lib/guest_sprintf.c
+++ b/tools/testing/selftests/kvm/lib/guest_sprintf.c
@@ -200,6 +200,13 @@ int guest_vsnprintf(char *buf, int n, const char *fmt, va_list args)
 			++fmt;
 		}
 
+		/*
+		 * Play nice with %llu, %llx, etc.  KVM selftests only support
+		 * 64-bit builds, so just treat %ll* the same as %l*.
+		 */
+		if (qualifier == 'l' && *fmt == 'l')
+			++fmt;
+
 		/* default base */
 		base = 10;
 
diff --git a/tools/testing/selftests/kvm/lib/x86_64/apic.c b/tools/testing/selftests/kvm/lib/x86_64/apic.c
index 7168e25..89153a3 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/apic.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/apic.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * tools/testing/selftests/kvm/lib/x86_64/processor.c
- *
  * Copyright (C) 2021, Google LLC.
  */
 
diff --git a/tools/testing/selftests/kvm/memslot_perf_test.c b/tools/testing/selftests/kvm/memslot_perf_test.c
index 20eb2e7..8698d1a 100644
--- a/tools/testing/selftests/kvm/memslot_perf_test.c
+++ b/tools/testing/selftests/kvm/memslot_perf_test.c
@@ -1033,9 +1033,8 @@ static bool test_loop(const struct test_data *data,
 		      struct test_result *rbestruntime)
 {
 	uint64_t maxslots;
-	struct test_result result;
+	struct test_result result = {};
 
-	result.nloops = 0;
 	if (!test_execute(targs->nslots, &maxslots, targs->seconds, data,
 			  &result.nloops,
 			  &result.slot_runtime, &result.guest_runtime)) {
@@ -1089,7 +1088,7 @@ int main(int argc, char *argv[])
 		.seconds = 5,
 		.runs = 1,
 	};
-	struct test_result rbestslottime;
+	struct test_result rbestslottime = {};
 	int tctr;
 
 	if (!check_memory_sizes())
@@ -1098,11 +1097,10 @@ int main(int argc, char *argv[])
 	if (!parse_args(argc, argv, &targs))
 		return -1;
 
-	rbestslottime.slottimens = 0;
 	for (tctr = targs.tfirst; tctr <= targs.tlast; tctr++) {
 		const struct test_data *data = &tests[tctr];
 		unsigned int runctr;
-		struct test_result rbestruntime;
+		struct test_result rbestruntime = {};
 
 		if (tctr > targs.tfirst)
 			pr_info("\n");
@@ -1110,7 +1108,6 @@ int main(int argc, char *argv[])
 		pr_info("Testing %s performance with %i runs, %d seconds each\n",
 			data->name, targs.runs, targs.seconds);
 
-		rbestruntime.runtimens = 0;
 		for (runctr = 0; runctr < targs.runs; runctr++)
 			if (!test_loop(data, &targs,
 				       &rbestslottime, &rbestruntime))
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index e446d76..6c12785 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * KVM_GET/SET_* tests
- *
  * Copyright (C) 2022, Red Hat, Inc.
  *
  * Tests for Hyper-V extensions to SVM.
diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
index 7f36c32..18ac5c1 100644
--- a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
+++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c
@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * tools/testing/selftests/kvm/nx_huge_page_test.c
- *
  * Usage: to be run via nx_huge_page_test.sh, which does the necessary
  * environment setup and teardown
  *
diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh
index 0560149..7cbb409 100755
--- a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh
+++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh
@@ -4,7 +4,6 @@
 # Wrapper script which performs setup and cleanup for nx_huge_pages_test.
 # Makes use of root privileges to set up huge pages and KVM module parameters.
 #
-# tools/testing/selftests/kvm/nx_huge_page_test.sh
 # Copyright (C) 2022, Google LLC.
 
 set -e
diff --git a/tools/testing/selftests/kvm/x86_64/tsc_scaling_sync.c b/tools/testing/selftests/kvm/x86_64/tsc_scaling_sync.c
index 5b66981..59c7304 100644
--- a/tools/testing/selftests/kvm/x86_64/tsc_scaling_sync.c
+++ b/tools/testing/selftests/kvm/x86_64/tsc_scaling_sync.c
@@ -1,10 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * svm_vmcall_test
- *
  * Copyright © 2021 Amazon.com, Inc. or its affiliates.
- *
- * Xen shared_info / pvclock testing
  */
 
 #include "test_util.h"
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index 05898ad..9ec9ab6 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -1,10 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * svm_vmcall_test
- *
  * Copyright © 2021 Amazon.com, Inc. or its affiliates.
- *
- * Xen shared_info / pvclock testing
  */
 
 #include "test_util.h"