debug_test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/* Test KVM debugging features. */
  3#include "kvm_util.h"
  4#include "test_util.h"
  5#include "sie.h"
  6
  7#include <linux/kvm.h>
  8
  9#define __LC_SVC_NEW_PSW 0x1c0
 10#define __LC_PGM_NEW_PSW 0x1d0
 11#define IPA0_DIAG 0x8300
 12#define PGM_SPECIFICATION 0x06
 13
 14/* Common code for testing single-stepping interruptions. */
 15extern char int_handler[];
 16asm("int_handler:\n"
 17    "j .\n");
 18
 19static struct kvm_vm *test_step_int_1(struct kvm_vcpu **vcpu, void *guest_code,
 20				      size_t new_psw_off, uint64_t *new_psw)
 21{
 22	struct kvm_guest_debug debug = {};
 23	struct kvm_regs regs;
 24	struct kvm_vm *vm;
 25	char *lowcore;
 26
 27	vm = vm_create_with_one_vcpu(vcpu, guest_code);
 28	lowcore = addr_gpa2hva(vm, 0);
 29	new_psw[0] = (*vcpu)->run->psw_mask;
 30	new_psw[1] = (uint64_t)int_handler;
 31	memcpy(lowcore + new_psw_off, new_psw, 16);
 32	vcpu_regs_get(*vcpu, &regs);
 33	regs.gprs[2] = -1;
 34	vcpu_regs_set(*vcpu, &regs);
 35	debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
 36	vcpu_guest_debug_set(*vcpu, &debug);
 37	vcpu_run(*vcpu);
 38
 39	return vm;
 40}
 41
 42static void test_step_int(void *guest_code, size_t new_psw_off)
 43{
 44	struct kvm_vcpu *vcpu;
 45	uint64_t new_psw[2];
 46	struct kvm_vm *vm;
 47
 48	vm = test_step_int_1(&vcpu, guest_code, new_psw_off, new_psw);
 49	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_DEBUG);
 50	TEST_ASSERT_EQ(vcpu->run->psw_mask, new_psw[0]);
 51	TEST_ASSERT_EQ(vcpu->run->psw_addr, new_psw[1]);
 52	kvm_vm_free(vm);
 53}
 54
 55/* Test single-stepping "boring" program interruptions. */
 56extern char test_step_pgm_guest_code[];
 57asm("test_step_pgm_guest_code:\n"
 58    ".insn rr,0x1d00,%r1,%r0 /* dr %r1,%r0 */\n"
 59    "j .\n");
 60
 61static void test_step_pgm(void)
 62{
 63	test_step_int(test_step_pgm_guest_code, __LC_PGM_NEW_PSW);
 64}
 65
 66/*
 67 * Test single-stepping program interruptions caused by DIAG.
 68 * Userspace emulation must not interfere with single-stepping.
 69 */
 70extern char test_step_pgm_diag_guest_code[];
 71asm("test_step_pgm_diag_guest_code:\n"
 72    "diag %r0,%r0,0\n"
 73    "j .\n");
 74
 75static void test_step_pgm_diag(void)
 76{
 77	struct kvm_s390_irq irq = {
 78		.type = KVM_S390_PROGRAM_INT,
 79		.u.pgm.code = PGM_SPECIFICATION,
 80	};
 81	struct kvm_vcpu *vcpu;
 82	uint64_t new_psw[2];
 83	struct kvm_vm *vm;
 84
 85	vm = test_step_int_1(&vcpu, test_step_pgm_diag_guest_code,
 86			     __LC_PGM_NEW_PSW, new_psw);
 87	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_S390_SIEIC);
 88	TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, ICPT_INST);
 89	TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa & 0xff00, IPA0_DIAG);
 90	vcpu_ioctl(vcpu, KVM_S390_IRQ, &irq);
 91	vcpu_run(vcpu);
 92	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_DEBUG);
 93	TEST_ASSERT_EQ(vcpu->run->psw_mask, new_psw[0]);
 94	TEST_ASSERT_EQ(vcpu->run->psw_addr, new_psw[1]);
 95	kvm_vm_free(vm);
 96}
 97
 98/*
 99 * Test single-stepping program interruptions caused by ISKE.
100 * CPUSTAT_KSS handling must not interfere with single-stepping.
101 */
102extern char test_step_pgm_iske_guest_code[];
103asm("test_step_pgm_iske_guest_code:\n"
104    "iske %r2,%r2\n"
105    "j .\n");
106
107static void test_step_pgm_iske(void)
108{
109	test_step_int(test_step_pgm_iske_guest_code, __LC_PGM_NEW_PSW);
110}
111
112/*
113 * Test single-stepping program interruptions caused by LCTL.
114 * KVM emulation must not interfere with single-stepping.
115 */
116extern char test_step_pgm_lctl_guest_code[];
117asm("test_step_pgm_lctl_guest_code:\n"
118    "lctl %c0,%c0,1\n"
119    "j .\n");
120
121static void test_step_pgm_lctl(void)
122{
123	test_step_int(test_step_pgm_lctl_guest_code, __LC_PGM_NEW_PSW);
124}
125
126/* Test single-stepping supervisor-call interruptions. */
127extern char test_step_svc_guest_code[];
128asm("test_step_svc_guest_code:\n"
129    "svc 0\n"
130    "j .\n");
131
132static void test_step_svc(void)
133{
134	test_step_int(test_step_svc_guest_code, __LC_SVC_NEW_PSW);
135}
136
137/* Run all tests above. */
138static struct testdef {
139	const char *name;
140	void (*test)(void);
141} testlist[] = {
142	{ "single-step pgm", test_step_pgm },
143	{ "single-step pgm caused by diag", test_step_pgm_diag },
144	{ "single-step pgm caused by iske", test_step_pgm_iske },
145	{ "single-step pgm caused by lctl", test_step_pgm_lctl },
146	{ "single-step svc", test_step_svc },
147};
148
149int main(int argc, char *argv[])
150{
151	int idx;
152
153	ksft_print_header();
154	ksft_set_plan(ARRAY_SIZE(testlist));
155	for (idx = 0; idx < ARRAY_SIZE(testlist); idx++) {
156		testlist[idx].test();
157		ksft_test_result_pass("%s\n", testlist[idx].name);
158	}
159	ksft_finished();
160}