[PATCH v3 6/6] KVM: PPC: selftests: Add interrupt performance tester

[Nicholas Piggin]

Add a little perf tester for interrupts that go to guest, host, and
userspace.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/powerpc/interrupt_perf.c    | 199 ++++++++++++++++++
 2 files changed, 200 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/powerpc/interrupt_perf.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index aa3a8ca676c2..834f98971b0c 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -184,6 +184,7 @@ TEST_GEN_PROGS_riscv += kvm_page_table_test
 TEST_GEN_PROGS_riscv += set_memory_region_test
 TEST_GEN_PROGS_riscv += kvm_binary_stats_test
 
+TEST_GEN_PROGS_powerpc += powerpc/interrupt_perf
 TEST_GEN_PROGS_powerpc += powerpc/null_test
 TEST_GEN_PROGS_powerpc += powerpc/rtas_hcall
 TEST_GEN_PROGS_powerpc += powerpc/tlbiel_test
diff --git a/tools/testing/selftests/kvm/powerpc/interrupt_perf.c b/tools/testing/selftests/kvm/powerpc/interrupt_perf.c
new file mode 100644
index 000000000000..50d078899e22
--- /dev/null
+++ b/tools/testing/selftests/kvm/powerpc/interrupt_perf.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test basic guest interrupt/exit performance.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sched.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/sysinfo.h>
+#include <signal.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "kselftest.h"
+#include "processor.h"
+#include "helpers.h"
+#include "hcall.h"
+
+static bool timeout;
+static unsigned long count;
+static struct kvm_vm *kvm_vm;
+
+static void set_timer(int sec)
+{
+	struct itimerval timer;
+
+	timeout = false;
+
+	timer.it_value.tv_sec  = sec;
+	timer.it_value.tv_usec = 0;
+	timer.it_interval = timer.it_value;
+	TEST_ASSERT(setitimer(ITIMER_REAL, &timer, NULL) == 0,
+			"setitimer failed %s", strerror(errno));
+}
+
+static void sigalrm_handler(int sig)
+{
+	timeout = true;
+	sync_global_to_guest(kvm_vm, timeout);
+}
+
+static void init_timers(void)
+{
+	TEST_ASSERT(signal(SIGALRM, sigalrm_handler) != SIG_ERR,
+		    "Failed to register SIGALRM handler, errno = %d (%s)",
+		    errno, strerror(errno));
+}
+
+static void program_interrupt_handler(struct ex_regs *regs)
+{
+	regs->nia += 4;
+}
+
+static void program_interrupt_guest_code(void)
+{
+	unsigned long nr = 0;
+
+	while (!timeout) {
+		asm volatile("trap");
+		nr++;
+		barrier();
+	}
+	count = nr;
+
+	GUEST_DONE();
+}
+
+static void program_interrupt_test(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	/* Create VM */
+	vm = vm_create_with_one_vcpu(&vcpu, program_interrupt_guest_code);
+	kvm_vm = vm;
+	vm_install_exception_handler(vm, 0x700, program_interrupt_handler);
+
+	set_timer(1);
+
+	while (!timeout) {
+		vcpu_run(vcpu);
+		barrier();
+	}
+
+	sync_global_from_guest(vm, count);
+
+	kvm_vm = NULL;
+	vm_install_exception_handler(vm, 0x700, NULL);
+
+	kvm_vm_free(vm);
+
+	printf("%lu guest interrupts per second\n", count);
+	count = 0;
+}
+
+static void heai_guest_code(void)
+{
+	unsigned long nr = 0;
+
+	while (!timeout) {
+		asm volatile(".long 0");
+		nr++;
+		barrier();
+	}
+	count = nr;
+
+	GUEST_DONE();
+}
+
+static void heai_test(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	/* Create VM */
+	vm = vm_create_with_one_vcpu(&vcpu, heai_guest_code);
+	kvm_vm = vm;
+	vm_install_exception_handler(vm, 0x700, program_interrupt_handler);
+
+	set_timer(1);
+
+	while (!timeout) {
+		vcpu_run(vcpu);
+		barrier();
+	}
+
+	sync_global_from_guest(vm, count);
+
+	kvm_vm = NULL;
+	vm_install_exception_handler(vm, 0x700, NULL);
+
+	kvm_vm_free(vm);
+
+	printf("%lu guest exits per second\n", count);
+	count = 0;
+}
+
+static void hcall_guest_code(void)
+{
+	for (;;)
+		hcall0(H_RTAS);
+}
+
+static void hcall_test(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	/* Create VM */
+	vm = vm_create_with_one_vcpu(&vcpu, hcall_guest_code);
+	kvm_vm = vm;
+
+	set_timer(1);
+
+	while (!timeout) {
+		vcpu_run(vcpu);
+		count++;
+		barrier();
+	}
+
+	kvm_vm = NULL;
+
+	kvm_vm_free(vm);
+
+	printf("%lu KVM exits per second\n", count);
+	count = 0;
+}
+
+struct testdef {
+	const char *name;
+	void (*test)(void);
+} testlist[] = {
+	{ "guest interrupt test", program_interrupt_test},
+	{ "guest exit test", heai_test},
+	{ "KVM exit test", hcall_test},
+};
+
+int main(int argc, char *argv[])
+{
+	int idx;
+
+	ksft_print_header();
+
+	ksft_set_plan(ARRAY_SIZE(testlist));
+
+	init_timers();
+
+	for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) {
+		testlist[idx].test();
+		ksft_test_result_pass("%s\n", testlist[idx].name);
+	}
+
+	ksft_finished();	/* Print results and exit() accordingly */
+}
-- 
2.40.1