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  #include "ucall_common.h"
10  
11  #define LABEL_ADDRESS(v) ((uint64_t)&(v))
12  
13  extern unsigned char sw_bp_1, sw_bp_2;
14  static uint64_t sw_bp_addr;
15  
guest_code(void)16  static void guest_code(void)
17  {
18  	asm volatile(
19  		".option push\n"
20  		".option norvc\n"
21  		"sw_bp_1: ebreak\n"
22  		"sw_bp_2: ebreak\n"
23  		".option pop\n"
24  	);
25  	GUEST_ASSERT_EQ(READ_ONCE(sw_bp_addr), LABEL_ADDRESS(sw_bp_2));
26  
27  	GUEST_DONE();
28  }
29  
guest_breakpoint_handler(struct ex_regs * regs)30  static void guest_breakpoint_handler(struct ex_regs *regs)
31  {
32  	WRITE_ONCE(sw_bp_addr, regs->epc);
33  	regs->epc += 4;
34  }
35  
main(void)36  int main(void)
37  {
38  	struct kvm_vm *vm;
39  	struct kvm_vcpu *vcpu;
40  	uint64_t pc;
41  	struct kvm_guest_debug debug = {
42  		.control = KVM_GUESTDBG_ENABLE,
43  	};
44  
45  	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG));
46  
47  	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
48  
49  	vm_init_vector_tables(vm);
50  	vcpu_init_vector_tables(vcpu);
51  	vm_install_exception_handler(vm, EXC_BREAKPOINT,
52  					guest_breakpoint_handler);
53  
54  	/*
55  	 * Enable the guest debug.
56  	 * ebreak should exit to the VMM with KVM_EXIT_DEBUG reason.
57  	 */
58  	vcpu_guest_debug_set(vcpu, &debug);
59  	vcpu_run(vcpu);
60  
61  	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_DEBUG);
62  
63  	vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.pc), &pc);
64  	TEST_ASSERT_EQ(pc, LABEL_ADDRESS(sw_bp_1));
65  
66  	/* skip sw_bp_1 */
67  	vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.pc), pc + 4);
68  
69  	/*
70  	 * Disable all debug controls.
71  	 * Guest should handle the ebreak without exiting to the VMM.
72  	 */
73  	memset(&debug, 0, sizeof(debug));
74  	vcpu_guest_debug_set(vcpu, &debug);
75  
76  	vcpu_run(vcpu);
77  
78  	TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE);
79  
80  	kvm_vm_free(vm);
81  
82  	return 0;
83  }
84