Subject: [PATCH 2/2] KVM: PPC: Add basic framework tests for kvm selftests

From: Nicholas Piggin <[email-masked]>
Date: Thu, 16 Mar 2023 13:17:32 +1000

Add some tests that exercise basic functions of the kvm selftests
framework, guest creation, ucalls, hcalls, copying data between guest
and host, interrupts and page faults.

These don't test KVM so much, but were useful when developing the
selftests support for powerpc.

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 tools/testing/selftests/kvm/Makefile          |   2 +
 .../selftests/kvm/include/powerpc/hcall.h     |   4 +-
 .../testing/selftests/kvm/powerpc/null_test.c | 186 ++++++++++++++++++
 .../selftests/kvm/powerpc/rtas_hcall.c        | 146 ++++++++++++++
 4 files changed, 337 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/kvm/powerpc/null_test.c
 create mode 100644 tools/testing/selftests/kvm/powerpc/rtas_hcall.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 081cee3ecc0c..1d9eb4f3284d 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -180,6 +180,8 @@ 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/null_test
+TEST_GEN_PROGS_powerpc += powerpc/rtas_hcall
 TEST_GEN_PROGS_powerpc += demand_paging_test
 TEST_GEN_PROGS_powerpc += dirty_log_test
 TEST_GEN_PROGS_powerpc += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/include/powerpc/hcall.h b/tools/testing/selftests/kvm/include/powerpc/hcall.h
index bbad5904f37a..cbcaf180c427 100644
--- a/tools/testing/selftests/kvm/include/powerpc/hcall.h
+++ b/tools/testing/selftests/kvm/include/powerpc/hcall.h
@@ -11,7 +11,9 @@
 #define H_UCALL	0
 #define UCALL_R4_UCALL	0x5715 // regular ucall, r5 contains ucall pointer
 #define UCALL_R4_EXCPT	0x1b0f // other exception, r5 contains vector, r6,7 SRRs
-			       // R4==0 is a simple asm exit
+#define UCALL_R4_SIMPLE	0x0000 // simple exit usable by asm with no ucall data
+
+#define H_RTAS		0xf000
 
 int64_t hcall0(uint64_t token);
 int64_t hcall1(uint64_t token, uint64_t arg1);
diff --git a/tools/testing/selftests/kvm/powerpc/null_test.c b/tools/testing/selftests/kvm/powerpc/null_test.c
new file mode 100644
index 000000000000..ee3cf20a5cf3
--- /dev/null
+++ b/tools/testing/selftests/kvm/powerpc/null_test.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tests for guest creation, run, ucall, interrupt, and vm dumping.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "kselftest.h"
+#include "processor.h"
+
+extern void guest_code_asm(void);
+asm(".global guest_code_asm");
+asm(".balign 4");
+asm("guest_code_asm:");
+asm("li 3,0"); // H_UCALL
+asm("li 4,0"); // UCALL_R4_SIMPLE
+asm("sc 1");
+
+static void guest_code_ucall(void)
+{
+	GUEST_DONE();
+}
+
+static void guest_code_trap(void)
+{
+	asm volatile("trap");
+}
+
+static void guest_code_dsi(void)
+{
+	*(volatile int *)0;
+}
+
+static void test_asm(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int ret;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_asm);
+
+	ret = _vcpu_run(vcpu);
+
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_NONE,
+		    "Invalid guest done status: exit_reason=%s\n",
+		    exit_reason_str(vcpu->run->exit_reason));
+
+	kvm_vm_free(vm);
+}
+
+static void test_ucall(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int ret;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_ucall);
+
+	ret = _vcpu_run(vcpu);
+
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_DONE,
+		    "Invalid guest done status: exit_reason=%s\n",
+		    exit_reason_str(vcpu->run->exit_reason));
+
+	kvm_vm_free(vm);
+}
+
+static bool got_trap;
+static bool trap_handler(struct kvm_vcpu *vcpu, unsigned trap)
+{
+	if (trap == 0x700) {
+		got_trap = true;
+		return true;
+	}
+	return false;
+}
+
+static void test_trap(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int ret;
+
+	interrupt_handler = trap_handler;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_trap);
+
+	ret = _vcpu_run(vcpu);
+
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	TEST_ASSERT(got_trap,
+		    "Invalid guest done status: exit_reason=%s\n",
+		    exit_reason_str(vcpu->run->exit_reason));
+
+	kvm_vm_free(vm);
+
+	interrupt_handler = NULL;
+}
+
+static bool got_dsi;
+static bool dsi_handler(struct kvm_vcpu *vcpu, unsigned trap)
+{
+	if (trap == 0x300) {
+		got_dsi = true;
+		return true;
+	}
+	return false;
+}
+
+static void test_dsi(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int ret;
+
+	interrupt_handler = dsi_handler;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_dsi);
+
+	ret = _vcpu_run(vcpu);
+
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	TEST_ASSERT(got_dsi,
+		    "Invalid guest done status: exit_reason=%s\n",
+		    exit_reason_str(vcpu->run->exit_reason));
+
+	vm_dump(stderr, vm, 2);
+
+	kvm_vm_free(vm);
+
+	interrupt_handler = NULL;
+}
+
+static void test_dump(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int ret;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_ucall);
+
+	ret = _vcpu_run(vcpu);
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+
+	printf("Testing vm_dump...\n");
+	vm_dump(stderr, vm, 2);
+
+	kvm_vm_free(vm);
+}
+
+
+struct testdef {
+	const char *name;
+	void (*test)(void);
+} testlist[] = {
+	{ "null asm test", test_asm},
+	{ "null ucall test", test_ucall},
+	{ "trap test", test_trap},
+	{ "page fault test", test_dsi},
+	{ "vm dump test", test_dump},
+};
+
+int main(int argc, char *argv[])
+{
+	int idx;
+
+	ksft_print_header();
+
+	ksft_set_plan(ARRAY_SIZE(testlist));
+
+	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 */
+}
diff --git a/tools/testing/selftests/kvm/powerpc/rtas_hcall.c b/tools/testing/selftests/kvm/powerpc/rtas_hcall.c
new file mode 100644
index 000000000000..17a580d7fa55
--- /dev/null
+++ b/tools/testing/selftests/kvm/powerpc/rtas_hcall.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test the KVM H_RTAS hcall and copying buffers between guest and host.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "kselftest.h"
+#include "hcall.h"
+
+struct rtas_args {
+	__be32 token;
+	__be32 nargs;
+	__be32 nret;
+	__be32 args[16];
+        __be32 *rets;     /* Pointer to return values in args[]. */
+};
+
+static void guest_code(void)
+{
+	struct rtas_args r;
+	int64_t rc;
+
+	r.token = cpu_to_be32(0xdeadbeef);
+	r.nargs = cpu_to_be32(3);
+	r.nret = cpu_to_be32(2);
+	r.rets = &r.args[3];
+	r.args[0] = cpu_to_be32(0x1000);
+	r.args[1] = cpu_to_be32(0x1001);
+	r.args[2] = cpu_to_be32(0x1002);
+	rc = hcall1(H_RTAS, (uint64_t)&r);
+	GUEST_ASSERT(rc == 0);
+	GUEST_ASSERT_1(be32_to_cpu(r.rets[0]) == 0xabc, be32_to_cpu(r.rets[0]));
+	GUEST_ASSERT_1(be32_to_cpu(r.rets[1]) == 0x123, be32_to_cpu(r.rets[1]));
+
+	GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_regs regs;
+	struct rtas_args *r;
+	vm_vaddr_t rtas_vaddr;
+	struct ucall uc;
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	uint64_t tmp;
+	int ret;
+
+	ksft_print_header();
+
+	ksft_set_plan(1);
+
+	/* Create VM */
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+
+	printf("Running H_RTAS guest vcpu.\n");
+
+	ret = _vcpu_run(vcpu);
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	switch ((tmp = get_ucall(vcpu, &uc))) {
+	case UCALL_NONE:
+		break; // good
+	case UCALL_DONE:
+		TEST_FAIL("Unexpected final guest exit %lu\n", tmp);
+		break;
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT_N(uc, "values: %lu (0x%lx)\n",
+				      GUEST_ASSERT_ARG(uc, 0),
+				      GUEST_ASSERT_ARG(uc, 0));
+		break;
+	default:
+		TEST_FAIL("Unexpected guest exit %lu\n", tmp);
+	}
+
+	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_PAPR_HCALL,
+		    "Expected PAPR_HCALL exit, got %s\n",
+		    exit_reason_str(vcpu->run->exit_reason));
+	TEST_ASSERT(vcpu->run->papr_hcall.nr == H_RTAS,
+		    "Expected H_RTAS exit, got %lld\n",
+		    vcpu->run->papr_hcall.nr);
+
+	printf("Got H_RTAS exit.\n");
+
+	vcpu_regs_get(vcpu, &regs);
+	rtas_vaddr = regs.gpr[4];
+	printf("H_RTAS rtas_args at gEA=0x%lx\n", rtas_vaddr);
+
+	r = addr_gva2hva(vm, rtas_vaddr);
+
+	TEST_ASSERT(r->token == cpu_to_be32(0xdeadbeef),
+		    "Expected RTAS token 0xdeadbeef, got 0x%x\n",
+		    be32_to_cpu(r->token));
+	TEST_ASSERT(r->nargs == cpu_to_be32(3),
+		    "Expected RTAS nargs 3, got %u\n",
+		    be32_to_cpu(r->nargs));
+	TEST_ASSERT(r->nret == cpu_to_be32(2),
+		    "Expected RTAS nret 2, got %u\n",
+		    be32_to_cpu(r->nret));
+	TEST_ASSERT(r->args[0] == cpu_to_be32(0x1000),
+		    "Expected args[0] to be 0x1000, got 0x%x\n",
+		    be32_to_cpu(r->args[0]));
+	TEST_ASSERT(r->args[1] == cpu_to_be32(0x1001),
+		    "Expected args[1] to be 0x1001, got 0x%x\n",
+		    be32_to_cpu(r->args[1]));
+	TEST_ASSERT(r->args[2] == cpu_to_be32(0x1002),
+		    "Expected args[2] to be 0x1002, got 0x%x\n",
+		    be32_to_cpu(r->args[2]));
+
+	printf("Guest rtas_args is correct, setting rets.\n");
+
+	r->args[3] = cpu_to_be32(0xabc);
+	r->args[4] = cpu_to_be32(0x123);
+
+	regs.gpr[3] = 0;
+	vcpu_regs_set(vcpu, &regs);
+
+	printf("Running H_RTAS guest vcpu again (hcall return H_SUCCESS).\n");
+
+	ret = _vcpu_run(vcpu);
+	TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
+	switch ((tmp = get_ucall(vcpu, &uc))) {
+	case UCALL_DONE:
+		printf("Got final guest exit.\n");
+		break;
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT_N(uc, "values: %lu (0x%lx)\n",
+				      GUEST_ASSERT_ARG(uc, 0),
+				      GUEST_ASSERT_ARG(uc, 0));
+		break;
+	default:
+		TEST_FAIL("Unexpected guest exit %lu\n", tmp);
+	}
+
+	kvm_vm_free(vm);
+
+	ksft_test_result_pass("%s\n", "null test");
+	ksft_finished();	/* Print results and exit() accordingly */
+}
-- 
2.37.2