1// SPDX-License-Identifier: GPL-2.0
2/*
3 * RISC-V KVM ebreak test.
4 *
5 * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd.
6 *
7 */
8#include "kvm_util.h"
9
10#define LABEL_ADDRESS(v) ((uint64_t)&(v))
11
12extern unsigned char sw_bp_1, sw_bp_2;
13static uint64_t sw_bp_addr;
14
15static void guest_code(void)
16{
17	asm volatile(
18		".option push\n"
19		".option norvc\n"
20		"sw_bp_1: ebreak\n"
21		"sw_bp_2: ebreak\n"
22		".option pop\n"
23	);
24	GUEST_ASSERT_EQ(READ_ONCE(sw_bp_addr), LABEL_ADDRESS(sw_bp_2));
25
26	GUEST_DONE();
27}
28
29static void guest_breakpoint_handler(struct ex_regs *regs)
30{
31	WRITE_ONCE(sw_bp_addr, regs->epc);
32	regs->epc += 4;
33}
34
35int main(void)
36{
37	struct kvm_vm *vm;
38	struct kvm_vcpu *vcpu;
39	uint64_t pc;
40	struct kvm_guest_debug debug = {
41		.control = KVM_GUESTDBG_ENABLE,
42	};
43
44	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG));
45
46	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
47
48	vm_init_vector_tables(vm);
49	vcpu_init_vector_tables(vcpu);
50	vm_install_exception_handler(vm, EXC_BREAKPOINT,
51					guest_breakpoint_handler);
52
53	/*
54	 * Enable the guest debug.
55	 * ebreak should exit to the VMM with KVM_EXIT_DEBUG reason.
56	 */
57	vcpu_guest_debug_set(vcpu, &debug);
58	vcpu_run(vcpu);
59
60	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_DEBUG);
61
62	vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.pc), &pc);
63	TEST_ASSERT_EQ(pc, LABEL_ADDRESS(sw_bp_1));
64
65	/* skip sw_bp_1 */
66	vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.pc), pc + 4);
67
68	/*
69	 * Disable all debug controls.
70	 * Guest should handle the ebreak without exiting to the VMM.
71	 */
72	memset(&debug, 0, sizeof(debug));
73	vcpu_guest_debug_set(vcpu, &debug);
74
75	vcpu_run(vcpu);
76
77	TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE);
78
79	kvm_vm_free(vm);
80
81	return 0;
82}
83