[linux-block.git] / tools / testing / selftests / kvm / x86_64 / debug_regs.c

// SPDX-License-Identifier: GPL-2.0
/*
 * KVM guest debug register tests
 *
 * Copyright (C) 2020, Red Hat, Inc.
 */
#include <stdio.h>
#include <string.h>
#include "kvm_util.h"
#include "processor.h"
#include "apic.h"

#define DR6_BD		(1 << 13)
#define DR7_GD		(1 << 13)

#define IRQ_VECTOR 0xAA

/* For testing data access debug BP */
uint32_t guest_value;

extern unsigned char sw_bp, hw_bp, write_data, ss_start, bd_start;

static void guest_code(void)
{
	/* Create a pending interrupt on current vCPU */
	x2apic_enable();
	x2apic_write_reg(APIC_ICR, APIC_DEST_SELF | APIC_INT_ASSERT |
			 APIC_DM_FIXED | IRQ_VECTOR);

	/*
	 * Software BP tests.
	 *
	 * NOTE: sw_bp need to be before the cmd here, because int3 is an
	 * exception rather than a normal trap for KVM_SET_GUEST_DEBUG (we
	 * capture it using the vcpu exception bitmap).
	 */
	asm volatile("sw_bp: int3");

	/* Hardware instruction BP test */
	asm volatile("hw_bp: nop");

	/* Hardware data BP test */
	asm volatile("mov $1234,%%rax;\n\t"
		     "mov %%rax,%0;\n\t write_data:"
		     : "=m" (guest_value) : : "rax");

	/*
	 * Single step test, covers 2 basic instructions and 2 emulated
	 *
	 * Enable interrupts during the single stepping to see that
	 * pending interrupt we raised is not handled due to KVM_GUESTDBG_BLOCKIRQ
	 */
	asm volatile("ss_start: "
		     "sti\n\t"
		     "xor %%eax,%%eax\n\t"
		     "cpuid\n\t"
		     "movl $0x1a0,%%ecx\n\t"
		     "rdmsr\n\t"
		     "cli\n\t"
		     : : : "eax", "ebx", "ecx", "edx");

	/* DR6.BD test */
	asm volatile("bd_start: mov %%dr0, %%rax" : : : "rax");
	GUEST_DONE();
}

#define  CAST_TO_RIP(v)  ((unsigned long long)&(v))

static void vcpu_skip_insn(struct kvm_vcpu *vcpu, int insn_len)
{
	struct kvm_regs regs;

	vcpu_regs_get(vcpu, &regs);
	regs.rip += insn_len;
	vcpu_regs_set(vcpu, &regs);
}

int main(void)
{
	struct kvm_guest_debug debug;
	unsigned long long target_dr6, target_rip;
	struct kvm_vcpu *vcpu;
	struct kvm_run *run;
	struct kvm_vm *vm;
	struct ucall uc;
	uint64_t cmd;
	int i;
	/* Instruction lengths starting at ss_start */
	int ss_size[6] = {
		1,		/* sti*/
		2,		/* xor */
		2,		/* cpuid */
		5,		/* mov */
		2,		/* rdmsr */
		1,		/* cli */
	};

	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG));

	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
	run = vcpu->run;

	/* Test software BPs - int3 */
	memset(&debug, 0, sizeof(debug));
	debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
	vcpu_guest_debug_set(vcpu, &debug);
	vcpu_run(vcpu);
	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
		    run->debug.arch.exception == BP_VECTOR &&
		    run->debug.arch.pc == CAST_TO_RIP(sw_bp),
		    "INT3: exit %d exception %d rip 0x%llx (should be 0x%llx)",
		    run->exit_reason, run->debug.arch.exception,
		    run->debug.arch.pc, CAST_TO_RIP(sw_bp));
	vcpu_skip_insn(vcpu, 1);

	/* Test instruction HW BP over DR[0-3] */
	for (i = 0; i < 4; i++) {
		memset(&debug, 0, sizeof(debug));
		debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
		debug.arch.debugreg[i] = CAST_TO_RIP(hw_bp);
		debug.arch.debugreg[7] = 0x400 | (1UL << (2*i+1));
		vcpu_guest_debug_set(vcpu, &debug);
		vcpu_run(vcpu);
		target_dr6 = 0xffff0ff0 | (1UL << i);
		TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
			    run->debug.arch.exception == DB_VECTOR &&
			    run->debug.arch.pc == CAST_TO_RIP(hw_bp) &&
			    run->debug.arch.dr6 == target_dr6,
			    "INS_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
			    "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
			    i, run->exit_reason, run->debug.arch.exception,
			    run->debug.arch.pc, CAST_TO_RIP(hw_bp),
			    run->debug.arch.dr6, target_dr6);
	}
	/* Skip "nop" */
	vcpu_skip_insn(vcpu, 1);

	/* Test data access HW BP over DR[0-3] */
	for (i = 0; i < 4; i++) {
		memset(&debug, 0, sizeof(debug));
		debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
		debug.arch.debugreg[i] = CAST_TO_RIP(guest_value);
		debug.arch.debugreg[7] = 0x00000400 | (1UL << (2*i+1)) |
		    (0x000d0000UL << (4*i));
		vcpu_guest_debug_set(vcpu, &debug);
		vcpu_run(vcpu);
		target_dr6 = 0xffff0ff0 | (1UL << i);
		TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
			    run->debug.arch.exception == DB_VECTOR &&
			    run->debug.arch.pc == CAST_TO_RIP(write_data) &&
			    run->debug.arch.dr6 == target_dr6,
			    "DATA_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
			    "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
			    i, run->exit_reason, run->debug.arch.exception,
			    run->debug.arch.pc, CAST_TO_RIP(write_data),
			    run->debug.arch.dr6, target_dr6);
		/* Rollback the 4-bytes "mov" */
		vcpu_skip_insn(vcpu, -7);
	}
	/* Skip the 4-bytes "mov" */
	vcpu_skip_insn(vcpu, 7);

	/* Test single step */
	target_rip = CAST_TO_RIP(ss_start);
	target_dr6 = 0xffff4ff0ULL;
	for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) {
		target_rip += ss_size[i];
		memset(&debug, 0, sizeof(debug));
		debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP |
				KVM_GUESTDBG_BLOCKIRQ;
		debug.arch.debugreg[7] = 0x00000400;
		vcpu_guest_debug_set(vcpu, &debug);
		vcpu_run(vcpu);
		TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
			    run->debug.arch.exception == DB_VECTOR &&
			    run->debug.arch.pc == target_rip &&
			    run->debug.arch.dr6 == target_dr6,
			    "SINGLE_STEP[%d]: exit %d exception %d rip 0x%llx "
			    "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
			    i, run->exit_reason, run->debug.arch.exception,
			    run->debug.arch.pc, target_rip, run->debug.arch.dr6,
			    target_dr6);
	}

	/* Finally test global disable */
	memset(&debug, 0, sizeof(debug));
	debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
	debug.arch.debugreg[7] = 0x400 | DR7_GD;
	vcpu_guest_debug_set(vcpu, &debug);
	vcpu_run(vcpu);
	target_dr6 = 0xffff0ff0 | DR6_BD;
	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
		    run->debug.arch.exception == DB_VECTOR &&
		    run->debug.arch.pc == CAST_TO_RIP(bd_start) &&
		    run->debug.arch.dr6 == target_dr6,
			    "DR7.GD: exit %d exception %d rip 0x%llx "
			    "(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
			    run->exit_reason, run->debug.arch.exception,
			    run->debug.arch.pc, target_rip, run->debug.arch.dr6,
			    target_dr6);

	/* Disable all debug controls, run to the end */
	memset(&debug, 0, sizeof(debug));
	vcpu_guest_debug_set(vcpu, &debug);

	vcpu_run(vcpu);
	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
	cmd = get_ucall(vcpu, &uc);
	TEST_ASSERT(cmd == UCALL_DONE, "UCALL_DONE");

	kvm_vm_free(vm);

	return 0;
}
Commit	Line	Data
449aa906 PX	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* KVM guest debug register tests
	4	*
	5	* Copyright (C) 2020, Red Hat, Inc.
	6	*/
	7	#include <stdio.h>
	8	#include <string.h>
	9	#include "kvm_util.h"
	10	#include "processor.h"
85cc207b	11	#include "apic.h"
449aa906	12
45981ded PB	13	#define DR6_BD (1 << 13)
	14	#define DR7_GD (1 << 13)
	15
85cc207b ML	16	#define IRQ_VECTOR 0xAA
85cc207b ML	17
449aa906 PX	18	/* For testing data access debug BP */
	19	uint32_t guest_value;
	20
45981ded	21	extern unsigned char sw_bp, hw_bp, write_data, ss_start, bd_start;
449aa906 PX	22
	23	static void guest_code(void)
	24	{
85cc207b ML	25	/* Create a pending interrupt on current vCPU */
	26	x2apic_enable();
	27	x2apic_write_reg(APIC_ICR, APIC_DEST_SELF \| APIC_INT_ASSERT \|
	28	APIC_DM_FIXED \| IRQ_VECTOR);
	29
449aa906 PX	30	/*
	31	* Software BP tests.
	32	*
	33	* NOTE: sw_bp need to be before the cmd here, because int3 is an
	34	* exception rather than a normal trap for KVM_SET_GUEST_DEBUG (we
	35	* capture it using the vcpu exception bitmap).
	36	*/
	37	asm volatile("sw_bp: int3");
	38
	39	/* Hardware instruction BP test */
	40	asm volatile("hw_bp: nop");
	41
	42	/* Hardware data BP test */
	43	asm volatile("mov $1234,%%rax;\n\t"
	44	"mov %%rax,%0;\n\t write_data:"
	45	: "=m" (guest_value) : : "rax");
	46
85cc207b ML	47	/*
	48	* Single step test, covers 2 basic instructions and 2 emulated
	49	*
	50	* Enable interrupts during the single stepping to see that
	51	* pending interrupt we raised is not handled due to KVM_GUESTDBG_BLOCKIRQ
	52	*/
449aa906	53	asm volatile("ss_start: "
85cc207b	54	"sti\n\t"
98b0bf02	55	"xor %%eax,%%eax\n\t"
449aa906 PX	56	"cpuid\n\t"
	57	"movl $0x1a0,%%ecx\n\t"
	58	"rdmsr\n\t"
85cc207b	59	"cli\n\t"
98b0bf02	60	: : : "eax", "ebx", "ecx", "edx");
449aa906	61
45981ded PB	62	/* DR6.BD test */
45981ded PB	63	asm volatile("bd_start: mov %%dr0, %%rax" : : : "rax");
449aa906 PX	64	GUEST_DONE();
	65	}
	66
449aa906	67	#define CAST_TO_RIP(v) ((unsigned long long)&(v))
2571bcdb SC	68
	69	static void vcpu_skip_insn(struct kvm_vcpu *vcpu, int insn_len)
	70	{
	71	struct kvm_regs regs;
	72
768e9a61	73	vcpu_regs_get(vcpu, &regs);
2571bcdb	74	regs.rip += insn_len;
768e9a61	75	vcpu_regs_set(vcpu, &regs);
2571bcdb	76	}
449aa906 PX	77
	78	int main(void)
	79	{
	80	struct kvm_guest_debug debug;
	81	unsigned long long target_dr6, target_rip;
28039449	82	struct kvm_vcpu *vcpu;
449aa906 PX	83	struct kvm_run *run;
	84	struct kvm_vm *vm;
	85	struct ucall uc;
	86	uint64_t cmd;
	87	int i;
	88	/* Instruction lengths starting at ss_start */
85cc207b ML	89	int ss_size[6] = {
85cc207b ML	90	1, /* sti*/
18391e5e	91	2, /* xor */
449aa906 PX	92	2, /* cpuid */
	93	5, /* mov */
	94	2, /* rdmsr */
85cc207b	95	1, /* cli */
449aa906 PX	96	};
449aa906 PX	97
7ed397d1	98	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG));
449aa906	99
28039449 SC	100	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
28039449 SC	101	run = vcpu->run;
449aa906 PX	102
449aa906 PX	103	/* Test software BPs - int3 */
28039449	104	memset(&debug, 0, sizeof(debug));
449aa906	105	debug.control = KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_USE_SW_BP;
768e9a61 SC	106	vcpu_guest_debug_set(vcpu, &debug);
768e9a61 SC	107	vcpu_run(vcpu);
449aa906 PX	108	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
	109	run->debug.arch.exception == BP_VECTOR &&
	110	run->debug.arch.pc == CAST_TO_RIP(sw_bp),
	111	"INT3: exit %d exception %d rip 0x%llx (should be 0x%llx)",
	112	run->exit_reason, run->debug.arch.exception,
	113	run->debug.arch.pc, CAST_TO_RIP(sw_bp));
2571bcdb	114	vcpu_skip_insn(vcpu, 1);
449aa906 PX	115
	116	/* Test instruction HW BP over DR[0-3] */
	117	for (i = 0; i < 4; i++) {
28039449	118	memset(&debug, 0, sizeof(debug));
449aa906 PX	119	debug.control = KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_USE_HW_BP;
	120	debug.arch.debugreg[i] = CAST_TO_RIP(hw_bp);
	121	debug.arch.debugreg[7] = 0x400 \| (1UL << (2*i+1));
768e9a61 SC	122	vcpu_guest_debug_set(vcpu, &debug);
768e9a61 SC	123	vcpu_run(vcpu);
449aa906 PX	124	target_dr6 = 0xffff0ff0 \| (1UL << i);
	125	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
	126	run->debug.arch.exception == DB_VECTOR &&
	127	run->debug.arch.pc == CAST_TO_RIP(hw_bp) &&
	128	run->debug.arch.dr6 == target_dr6,
	129	"INS_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
	130	"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
	131	i, run->exit_reason, run->debug.arch.exception,
	132	run->debug.arch.pc, CAST_TO_RIP(hw_bp),
	133	run->debug.arch.dr6, target_dr6);
	134	}
	135	/* Skip "nop" */
2571bcdb	136	vcpu_skip_insn(vcpu, 1);
449aa906 PX	137
	138	/* Test data access HW BP over DR[0-3] */
	139	for (i = 0; i < 4; i++) {
28039449	140	memset(&debug, 0, sizeof(debug));
449aa906 PX	141	debug.control = KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_USE_HW_BP;
	142	debug.arch.debugreg[i] = CAST_TO_RIP(guest_value);
	143	debug.arch.debugreg[7] = 0x00000400 \| (1UL << (2*i+1)) \|
	144	(0x000d0000UL << (4*i));
768e9a61 SC	145	vcpu_guest_debug_set(vcpu, &debug);
768e9a61 SC	146	vcpu_run(vcpu);
449aa906 PX	147	target_dr6 = 0xffff0ff0 \| (1UL << i);
	148	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
	149	run->debug.arch.exception == DB_VECTOR &&
	150	run->debug.arch.pc == CAST_TO_RIP(write_data) &&
	151	run->debug.arch.dr6 == target_dr6,
	152	"DATA_HW_BP (DR%d): exit %d exception %d rip 0x%llx "
	153	"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
	154	i, run->exit_reason, run->debug.arch.exception,
	155	run->debug.arch.pc, CAST_TO_RIP(write_data),
	156	run->debug.arch.dr6, target_dr6);
	157	/* Rollback the 4-bytes "mov" */
2571bcdb	158	vcpu_skip_insn(vcpu, -7);
449aa906 PX	159	}
449aa906 PX	160	/* Skip the 4-bytes "mov" */
2571bcdb	161	vcpu_skip_insn(vcpu, 7);
449aa906 PX	162
	163	/* Test single step */
	164	target_rip = CAST_TO_RIP(ss_start);
	165	target_dr6 = 0xffff4ff0ULL;
449aa906 PX	166	for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) {
449aa906 PX	167	target_rip += ss_size[i];
28039449	168	memset(&debug, 0, sizeof(debug));
85cc207b ML	169	debug.control = KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_SINGLESTEP \|
85cc207b ML	170	KVM_GUESTDBG_BLOCKIRQ;
449aa906	171	debug.arch.debugreg[7] = 0x00000400;
768e9a61 SC	172	vcpu_guest_debug_set(vcpu, &debug);
768e9a61 SC	173	vcpu_run(vcpu);
449aa906 PX	174	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
	175	run->debug.arch.exception == DB_VECTOR &&
	176	run->debug.arch.pc == target_rip &&
	177	run->debug.arch.dr6 == target_dr6,
	178	"SINGLE_STEP[%d]: exit %d exception %d rip 0x%llx "
	179	"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
	180	i, run->exit_reason, run->debug.arch.exception,
	181	run->debug.arch.pc, target_rip, run->debug.arch.dr6,
	182	target_dr6);
	183	}
	184
45981ded	185	/* Finally test global disable */
28039449	186	memset(&debug, 0, sizeof(debug));
45981ded PB	187	debug.control = KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_USE_HW_BP;
45981ded PB	188	debug.arch.debugreg[7] = 0x400 \| DR7_GD;
768e9a61 SC	189	vcpu_guest_debug_set(vcpu, &debug);
768e9a61 SC	190	vcpu_run(vcpu);
45981ded PB	191	target_dr6 = 0xffff0ff0 \| DR6_BD;
	192	TEST_ASSERT(run->exit_reason == KVM_EXIT_DEBUG &&
	193	run->debug.arch.exception == DB_VECTOR &&
	194	run->debug.arch.pc == CAST_TO_RIP(bd_start) &&
	195	run->debug.arch.dr6 == target_dr6,
	196	"DR7.GD: exit %d exception %d rip 0x%llx "
	197	"(should be 0x%llx) dr6 0x%llx (should be 0x%llx)",
	198	run->exit_reason, run->debug.arch.exception,
	199	run->debug.arch.pc, target_rip, run->debug.arch.dr6,
	200	target_dr6);
	201
449aa906	202	/* Disable all debug controls, run to the end */
28039449	203	memset(&debug, 0, sizeof(debug));
768e9a61	204	vcpu_guest_debug_set(vcpu, &debug);
449aa906	205
768e9a61	206	vcpu_run(vcpu);
c96f57b0	207	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
768e9a61	208	cmd = get_ucall(vcpu, &uc);
449aa906 PX	209	TEST_ASSERT(cmd == UCALL_DONE, "UCALL_DONE");
	210
	211	kvm_vm_free(vm);
	212
	213	return 0;
	214	}