1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Test for x86 KVM_CAP_SYNC_REGS
4  *
5  * Copyright (C) 2018, Google LLC.
6  *
7  * Verifies expected behavior of x86 KVM_CAP_SYNC_REGS functionality,
8  * including requesting an invalid register set, updates to/from values
9  * in kvm_run.s.regs when kvm_valid_regs and kvm_dirty_regs are toggled.
10  */
11 
12 #define _GNU_SOURCE /* for program_invocation_short_name */
13 #include <fcntl.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <sys/ioctl.h>
18 
19 #include "test_util.h"
20 #include "kvm_util.h"
21 #include "processor.h"
22 
23 #define VCPU_ID 5
24 
25 #define UCALL_PIO_PORT ((uint16_t)0x1000)
26 
27 struct ucall uc_none = {
28 	.cmd = UCALL_NONE,
29 };
30 
31 /*
32  * ucall is embedded here to protect against compiler reshuffling registers
33  * before calling a function. In this test we only need to get KVM_EXIT_IO
34  * vmexit and preserve RBX, no additional information is needed.
35  */
36 void guest_code(void)
37 {
38 	asm volatile("1: in %[port], %%al\n"
39 		     "add $0x1, %%rbx\n"
40 		     "jmp 1b"
41 		     : : [port] "d" (UCALL_PIO_PORT), "D" (&uc_none)
42 		     : "rax", "rbx");
43 }
44 
45 static void compare_regs(struct kvm_regs *left, struct kvm_regs *right)
46 {
47 #define REG_COMPARE(reg) \
48 	TEST_ASSERT(left->reg == right->reg, \
49 		    "Register " #reg \
50 		    " values did not match: 0x%llx, 0x%llx\n", \
51 		    left->reg, right->reg)
52 	REG_COMPARE(rax);
53 	REG_COMPARE(rbx);
54 	REG_COMPARE(rcx);
55 	REG_COMPARE(rdx);
56 	REG_COMPARE(rsi);
57 	REG_COMPARE(rdi);
58 	REG_COMPARE(rsp);
59 	REG_COMPARE(rbp);
60 	REG_COMPARE(r8);
61 	REG_COMPARE(r9);
62 	REG_COMPARE(r10);
63 	REG_COMPARE(r11);
64 	REG_COMPARE(r12);
65 	REG_COMPARE(r13);
66 	REG_COMPARE(r14);
67 	REG_COMPARE(r15);
68 	REG_COMPARE(rip);
69 	REG_COMPARE(rflags);
70 #undef REG_COMPARE
71 }
72 
73 static void compare_sregs(struct kvm_sregs *left, struct kvm_sregs *right)
74 {
75 }
76 
77 static void compare_vcpu_events(struct kvm_vcpu_events *left,
78 				struct kvm_vcpu_events *right)
79 {
80 }
81 
82 #define TEST_SYNC_FIELDS   (KVM_SYNC_X86_REGS|KVM_SYNC_X86_SREGS|KVM_SYNC_X86_EVENTS)
83 #define INVALID_SYNC_FIELD 0x80000000
84 
85 int main(int argc, char *argv[])
86 {
87 	struct kvm_vm *vm;
88 	struct kvm_run *run;
89 	struct kvm_regs regs;
90 	struct kvm_sregs sregs;
91 	struct kvm_vcpu_events events;
92 	int rv, cap;
93 
94 	/* Tell stdout not to buffer its content */
95 	setbuf(stdout, NULL);
96 
97 	cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
98 	if ((cap & TEST_SYNC_FIELDS) != TEST_SYNC_FIELDS) {
99 		print_skip("KVM_CAP_SYNC_REGS not supported");
100 		exit(KSFT_SKIP);
101 	}
102 	if ((cap & INVALID_SYNC_FIELD) != 0) {
103 		print_skip("The \"invalid\" field is not invalid");
104 		exit(KSFT_SKIP);
105 	}
106 
107 	/* Create VM */
108 	vm = vm_create_default(VCPU_ID, 0, guest_code);
109 
110 	run = vcpu_state(vm, VCPU_ID);
111 
112 	/* Request reading invalid register set from VCPU. */
113 	run->kvm_valid_regs = INVALID_SYNC_FIELD;
114 	rv = _vcpu_run(vm, VCPU_ID);
115 	TEST_ASSERT(rv < 0 && errno == EINVAL,
116 		    "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
117 		    rv);
118 	vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
119 
120 	run->kvm_valid_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
121 	rv = _vcpu_run(vm, VCPU_ID);
122 	TEST_ASSERT(rv < 0 && errno == EINVAL,
123 		    "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
124 		    rv);
125 	vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
126 
127 	/* Request setting invalid register set into VCPU. */
128 	run->kvm_dirty_regs = INVALID_SYNC_FIELD;
129 	rv = _vcpu_run(vm, VCPU_ID);
130 	TEST_ASSERT(rv < 0 && errno == EINVAL,
131 		    "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
132 		    rv);
133 	vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
134 
135 	run->kvm_dirty_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
136 	rv = _vcpu_run(vm, VCPU_ID);
137 	TEST_ASSERT(rv < 0 && errno == EINVAL,
138 		    "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
139 		    rv);
140 	vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
141 
142 	/* Request and verify all valid register sets. */
143 	/* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */
144 	run->kvm_valid_regs = TEST_SYNC_FIELDS;
145 	rv = _vcpu_run(vm, VCPU_ID);
146 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
147 		    "Unexpected exit reason: %u (%s),\n",
148 		    run->exit_reason,
149 		    exit_reason_str(run->exit_reason));
150 
151 	vcpu_regs_get(vm, VCPU_ID, &regs);
152 	compare_regs(&regs, &run->s.regs.regs);
153 
154 	vcpu_sregs_get(vm, VCPU_ID, &sregs);
155 	compare_sregs(&sregs, &run->s.regs.sregs);
156 
157 	vcpu_events_get(vm, VCPU_ID, &events);
158 	compare_vcpu_events(&events, &run->s.regs.events);
159 
160 	/* Set and verify various register values. */
161 	run->s.regs.regs.rbx = 0xBAD1DEA;
162 	run->s.regs.sregs.apic_base = 1 << 11;
163 	/* TODO run->s.regs.events.XYZ = ABC; */
164 
165 	run->kvm_valid_regs = TEST_SYNC_FIELDS;
166 	run->kvm_dirty_regs = KVM_SYNC_X86_REGS | KVM_SYNC_X86_SREGS;
167 	rv = _vcpu_run(vm, VCPU_ID);
168 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
169 		    "Unexpected exit reason: %u (%s),\n",
170 		    run->exit_reason,
171 		    exit_reason_str(run->exit_reason));
172 	TEST_ASSERT(run->s.regs.regs.rbx == 0xBAD1DEA + 1,
173 		    "rbx sync regs value incorrect 0x%llx.",
174 		    run->s.regs.regs.rbx);
175 	TEST_ASSERT(run->s.regs.sregs.apic_base == 1 << 11,
176 		    "apic_base sync regs value incorrect 0x%llx.",
177 		    run->s.regs.sregs.apic_base);
178 
179 	vcpu_regs_get(vm, VCPU_ID, &regs);
180 	compare_regs(&regs, &run->s.regs.regs);
181 
182 	vcpu_sregs_get(vm, VCPU_ID, &sregs);
183 	compare_sregs(&sregs, &run->s.regs.sregs);
184 
185 	vcpu_events_get(vm, VCPU_ID, &events);
186 	compare_vcpu_events(&events, &run->s.regs.events);
187 
188 	/* Clear kvm_dirty_regs bits, verify new s.regs values are
189 	 * overwritten with existing guest values.
190 	 */
191 	run->kvm_valid_regs = TEST_SYNC_FIELDS;
192 	run->kvm_dirty_regs = 0;
193 	run->s.regs.regs.rbx = 0xDEADBEEF;
194 	rv = _vcpu_run(vm, VCPU_ID);
195 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
196 		    "Unexpected exit reason: %u (%s),\n",
197 		    run->exit_reason,
198 		    exit_reason_str(run->exit_reason));
199 	TEST_ASSERT(run->s.regs.regs.rbx != 0xDEADBEEF,
200 		    "rbx sync regs value incorrect 0x%llx.",
201 		    run->s.regs.regs.rbx);
202 
203 	/* Clear kvm_valid_regs bits and kvm_dirty_bits.
204 	 * Verify s.regs values are not overwritten with existing guest values
205 	 * and that guest values are not overwritten with kvm_sync_regs values.
206 	 */
207 	run->kvm_valid_regs = 0;
208 	run->kvm_dirty_regs = 0;
209 	run->s.regs.regs.rbx = 0xAAAA;
210 	regs.rbx = 0xBAC0;
211 	vcpu_regs_set(vm, VCPU_ID, &regs);
212 	rv = _vcpu_run(vm, VCPU_ID);
213 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
214 		    "Unexpected exit reason: %u (%s),\n",
215 		    run->exit_reason,
216 		    exit_reason_str(run->exit_reason));
217 	TEST_ASSERT(run->s.regs.regs.rbx == 0xAAAA,
218 		    "rbx sync regs value incorrect 0x%llx.",
219 		    run->s.regs.regs.rbx);
220 	vcpu_regs_get(vm, VCPU_ID, &regs);
221 	TEST_ASSERT(regs.rbx == 0xBAC0 + 1,
222 		    "rbx guest value incorrect 0x%llx.",
223 		    regs.rbx);
224 
225 	/* Clear kvm_valid_regs bits. Verify s.regs values are not overwritten
226 	 * with existing guest values but that guest values are overwritten
227 	 * with kvm_sync_regs values.
228 	 */
229 	run->kvm_valid_regs = 0;
230 	run->kvm_dirty_regs = TEST_SYNC_FIELDS;
231 	run->s.regs.regs.rbx = 0xBBBB;
232 	rv = _vcpu_run(vm, VCPU_ID);
233 	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
234 		    "Unexpected exit reason: %u (%s),\n",
235 		    run->exit_reason,
236 		    exit_reason_str(run->exit_reason));
237 	TEST_ASSERT(run->s.regs.regs.rbx == 0xBBBB,
238 		    "rbx sync regs value incorrect 0x%llx.",
239 		    run->s.regs.regs.rbx);
240 	vcpu_regs_get(vm, VCPU_ID, &regs);
241 	TEST_ASSERT(regs.rbx == 0xBBBB + 1,
242 		    "rbx guest value incorrect 0x%llx.",
243 		    regs.rbx);
244 
245 	kvm_vm_free(vm);
246 
247 	return 0;
248 }
249