[PATCH v2] selftests/kvm: Allow specify physical cpu list in demand paging test

[Peter Xu <peterx@redhat.com>]

Mimic dirty log test to allow specify physical cpu pinning for vcpu threads.
Put the help message into a general helper as suggested by Sean.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tools/testing/selftests/kvm/demand_paging_test.c  | 15 +++++++++++++--
 tools/testing/selftests/kvm/dirty_log_perf_test.c | 12 +-----------
 .../testing/selftests/kvm/include/kvm_util_base.h |  1 +
 tools/testing/selftests/kvm/lib/kvm_util.c        | 15 +++++++++++++++
 4 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index bdb8e0748154..8581478ed4eb 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -220,7 +220,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 static void help(char *name)
 {
 	puts("");
-	printf("usage: %s [-h] [-m vm_mode] [-u uffd_mode] [-a]\n"
+	printf("usage: %s [-h] [-m vm_mode] [-u uffd_mode] [-a] [-c cpu_list]\n"
 		   "          [-d uffd_delay_usec] [-r readers_per_uffd] [-b memory]\n"
 		   "          [-s type] [-v vcpus] [-o]\n", name);
 	guest_modes_help();
@@ -229,6 +229,7 @@ static void help(char *name)
 	printf(" -a: Use a single userfaultfd for all of guest memory, instead of\n"
 		   "     creating one for each region paged by a unique vCPU\n"
 		   "     Set implicitly with -o, and no effect without -u.\n");
+	kvm_vcpu_pinning_help();
 	printf(" -d: add a delay in usec to the User Fault\n"
 	       "     FD handler to simulate demand paging\n"
 	       "     overheads. Ignored without -u.\n");
@@ -247,6 +248,7 @@ static void help(char *name)
 int main(int argc, char *argv[])
 {
 	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
+	const char *cpulist = NULL;
 	struct test_params p = {
 		.src_type = DEFAULT_VM_MEM_SRC,
 		.partition_vcpu_memory_access = true,
@@ -257,7 +259,7 @@ int main(int argc, char *argv[])
 
 	guest_modes_append_default();
 
-	while ((opt = getopt(argc, argv, "ahom:u:d:b:s:v:r:")) != -1) {
+	while ((opt = getopt(argc, argv, "ac:hom:u:d:b:s:v:r:")) != -1) {
 		switch (opt) {
 		case 'm':
 			guest_modes_cmdline(optarg);
@@ -272,6 +274,9 @@ int main(int argc, char *argv[])
 		case 'a':
 			p.single_uffd = true;
 			break;
+		case 'c':
+			cpulist = optarg;
+			break;
 		case 'd':
 			p.uffd_delay = strtoul(optarg, NULL, 0);
 			TEST_ASSERT(p.uffd_delay >= 0, "A negative UFFD delay is not supported.");
@@ -309,6 +314,12 @@ int main(int argc, char *argv[])
 		TEST_FAIL("userfaultfd MINOR mode requires shared memory; pick a different -s");
 	}
 
+	if (cpulist) {
+		kvm_parse_vcpu_pinning(cpulist, memstress_args.vcpu_to_pcpu,
+				       nr_vcpus);
+		memstress_args.pin_vcpus = true;
+	}
+
 	for_each_guest_mode(run_test, &p);
 
 	return 0;
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index e9d6d1aecf89..a17d4ebebe55 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -402,17 +402,7 @@ static void help(char *name)
 	       "     so -w X means each page has an X%% chance of writing\n"
 	       "     and a (100-X)%% chance of reading.\n"
 	       "     (default: 100 i.e. all pages are written to.)\n");
-	printf(" -c: Pin tasks to physical CPUs.  Takes a list of comma separated\n"
-	       "     values (target pCPU), one for each vCPU, plus an optional\n"
-	       "     entry for the main application task (specified via entry\n"
-	       "     <nr_vcpus + 1>).  If used, entries must be provided for all\n"
-	       "     vCPUs, i.e. pinning vCPUs is all or nothing.\n\n"
-	       "     E.g. to create 3 vCPUs, pin vCPU0=>pCPU22, vCPU1=>pCPU23,\n"
-	       "     vCPU2=>pCPU24, and pin the application task to pCPU50:\n\n"
-	       "         ./dirty_log_perf_test -v 3 -c 22,23,24,50\n\n"
-	       "     To leave the application task unpinned, drop the final entry:\n\n"
-	       "         ./dirty_log_perf_test -v 3 -c 22,23,24\n\n"
-	       "     (default: no pinning)\n");
+	kvm_vcpu_pinning_help();
 	puts("");
 	exit(0);
 }
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index fbc2a79369b8..dc8afe64cfb7 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -734,6 +734,7 @@ struct kvm_vcpu *vm_recreate_with_one_vcpu(struct kvm_vm *vm);
 void kvm_pin_this_task_to_pcpu(uint32_t pcpu);
 void kvm_parse_vcpu_pinning(const char *pcpus_string, uint32_t vcpu_to_pcpu[],
 			    int nr_vcpus);
+void kvm_vcpu_pinning_help(void);
 
 unsigned long vm_compute_max_gfn(struct kvm_vm *vm);
 unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 8ec20ac33de0..5c9b9706f56a 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -489,6 +489,21 @@ static uint32_t parse_pcpu(const char *cpu_str, const cpu_set_t *allowed_mask)
 	return pcpu;
 }
 
+void kvm_vcpu_pinning_help(void)
+{
+	printf(" -c: Pin tasks to physical CPUs.  Takes a list of comma separated\n"
+	       "     values (target pCPU), one for each vCPU, plus an optional\n"
+	       "     entry for the main application task (specified via entry\n"
+	       "     <nr_vcpus + 1>).  If used, entries must be provided for all\n"
+	       "     vCPUs, i.e. pinning vCPUs is all or nothing.\n\n"
+	       "     E.g. to create 3 vCPUs, pin vCPU0=>pCPU22, vCPU1=>pCPU23,\n"
+	       "     vCPU2=>pCPU24, and pin the application task to pCPU50:\n\n"
+	       "         ./dirty_log_perf_test -v 3 -c 22,23,24,50\n\n"
+	       "     To leave the application task unpinned, drop the final entry:\n\n"
+	       "         ./dirty_log_perf_test -v 3 -c 22,23,24\n\n"
+	       "     (default: no pinning)\n");
+}
+
 void kvm_parse_vcpu_pinning(const char *pcpus_string, uint32_t vcpu_to_pcpu[],
 			    int nr_vcpus)
 {
-- 
2.40.1