1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * KVM/MIPS: Deliver/Emulate exceptions to the guest kernel
7 *
8 * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
9 * Authors: Sanjay Lal <sanjayl@kymasys.com>
10 */
11
12 #include <linux/errno.h>
13 #include <linux/err.h>
14 #include <linux/module.h>
15 #include <linux/vmalloc.h>
16
17 #include <linux/kvm_host.h>
18
19 #include "kvm_mips_opcode.h"
20 #include "kvm_mips_int.h"
21
kvm_trap_emul_gva_to_gpa_cb(gva_t gva)22 static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
23 {
24 gpa_t gpa;
25 uint32_t kseg = KSEGX(gva);
26
27 if ((kseg == CKSEG0) || (kseg == CKSEG1))
28 gpa = CPHYSADDR(gva);
29 else {
30 printk("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
31 kvm_mips_dump_host_tlbs();
32 gpa = KVM_INVALID_ADDR;
33 }
34
35 #ifdef DEBUG
36 kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
37 #endif
38
39 return gpa;
40 }
41
42
kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu * vcpu)43 static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
44 {
45 struct kvm_run *run = vcpu->run;
46 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
47 unsigned long cause = vcpu->arch.host_cp0_cause;
48 enum emulation_result er = EMULATE_DONE;
49 int ret = RESUME_GUEST;
50
51 if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
52 er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
53 } else
54 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
55
56 switch (er) {
57 case EMULATE_DONE:
58 ret = RESUME_GUEST;
59 break;
60
61 case EMULATE_FAIL:
62 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
63 ret = RESUME_HOST;
64 break;
65
66 case EMULATE_WAIT:
67 run->exit_reason = KVM_EXIT_INTR;
68 ret = RESUME_HOST;
69 break;
70
71 default:
72 BUG();
73 }
74 return ret;
75 }
76
kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu * vcpu)77 static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
78 {
79 struct kvm_run *run = vcpu->run;
80 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
81 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
82 unsigned long cause = vcpu->arch.host_cp0_cause;
83 enum emulation_result er = EMULATE_DONE;
84 int ret = RESUME_GUEST;
85
86 if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
87 || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
88 #ifdef DEBUG
89 kvm_debug
90 ("USER/KSEG23 ADDR TLB MOD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
91 cause, opc, badvaddr);
92 #endif
93 er = kvm_mips_handle_tlbmod(cause, opc, run, vcpu);
94
95 if (er == EMULATE_DONE)
96 ret = RESUME_GUEST;
97 else {
98 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
99 ret = RESUME_HOST;
100 }
101 } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
102 /* XXXKYMA: The guest kernel does not expect to get this fault when we are not
103 * using HIGHMEM. Need to address this in a HIGHMEM kernel
104 */
105 printk
106 ("TLB MOD fault not handled, cause %#lx, PC: %p, BadVaddr: %#lx\n",
107 cause, opc, badvaddr);
108 kvm_mips_dump_host_tlbs();
109 kvm_arch_vcpu_dump_regs(vcpu);
110 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
111 ret = RESUME_HOST;
112 } else {
113 printk
114 ("Illegal TLB Mod fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
115 cause, opc, badvaddr);
116 kvm_mips_dump_host_tlbs();
117 kvm_arch_vcpu_dump_regs(vcpu);
118 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
119 ret = RESUME_HOST;
120 }
121 return ret;
122 }
123
kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu * vcpu)124 static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
125 {
126 struct kvm_run *run = vcpu->run;
127 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
128 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
129 unsigned long cause = vcpu->arch.host_cp0_cause;
130 enum emulation_result er = EMULATE_DONE;
131 int ret = RESUME_GUEST;
132
133 if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
134 && KVM_GUEST_KERNEL_MODE(vcpu)) {
135 if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
136 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
137 ret = RESUME_HOST;
138 }
139 } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
140 || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
141 #ifdef DEBUG
142 kvm_debug
143 ("USER ADDR TLB LD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
144 cause, opc, badvaddr);
145 #endif
146 er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
147 if (er == EMULATE_DONE)
148 ret = RESUME_GUEST;
149 else {
150 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
151 ret = RESUME_HOST;
152 }
153 } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
154 /* All KSEG0 faults are handled by KVM, as the guest kernel does not
155 * expect to ever get them
156 */
157 if (kvm_mips_handle_kseg0_tlb_fault
158 (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
159 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
160 ret = RESUME_HOST;
161 }
162 } else {
163 kvm_err
164 ("Illegal TLB LD fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
165 cause, opc, badvaddr);
166 kvm_mips_dump_host_tlbs();
167 kvm_arch_vcpu_dump_regs(vcpu);
168 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
169 ret = RESUME_HOST;
170 }
171 return ret;
172 }
173
kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu * vcpu)174 static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
175 {
176 struct kvm_run *run = vcpu->run;
177 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
178 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
179 unsigned long cause = vcpu->arch.host_cp0_cause;
180 enum emulation_result er = EMULATE_DONE;
181 int ret = RESUME_GUEST;
182
183 if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
184 && KVM_GUEST_KERNEL_MODE(vcpu)) {
185 if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
186 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
187 ret = RESUME_HOST;
188 }
189 } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
190 || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
191 #ifdef DEBUG
192 kvm_debug("USER ADDR TLB ST fault: PC: %#lx, BadVaddr: %#lx\n",
193 vcpu->arch.pc, badvaddr);
194 #endif
195
196 /* User Address (UA) fault, this could happen if
197 * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
198 * case we pass on the fault to the guest kernel and let it handle it.
199 * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
200 * case we inject the TLB from the Guest TLB into the shadow host TLB
201 */
202
203 er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
204 if (er == EMULATE_DONE)
205 ret = RESUME_GUEST;
206 else {
207 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
208 ret = RESUME_HOST;
209 }
210 } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
211 if (kvm_mips_handle_kseg0_tlb_fault
212 (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
213 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
214 ret = RESUME_HOST;
215 }
216 } else {
217 printk
218 ("Illegal TLB ST fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
219 cause, opc, badvaddr);
220 kvm_mips_dump_host_tlbs();
221 kvm_arch_vcpu_dump_regs(vcpu);
222 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
223 ret = RESUME_HOST;
224 }
225 return ret;
226 }
227
kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu * vcpu)228 static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
229 {
230 struct kvm_run *run = vcpu->run;
231 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
232 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
233 unsigned long cause = vcpu->arch.host_cp0_cause;
234 enum emulation_result er = EMULATE_DONE;
235 int ret = RESUME_GUEST;
236
237 if (KVM_GUEST_KERNEL_MODE(vcpu)
238 && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
239 #ifdef DEBUG
240 kvm_debug("Emulate Store to MMIO space\n");
241 #endif
242 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
243 if (er == EMULATE_FAIL) {
244 printk("Emulate Store to MMIO space failed\n");
245 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
246 ret = RESUME_HOST;
247 } else {
248 run->exit_reason = KVM_EXIT_MMIO;
249 ret = RESUME_HOST;
250 }
251 } else {
252 printk
253 ("Address Error (STORE): cause %#lx, PC: %p, BadVaddr: %#lx\n",
254 cause, opc, badvaddr);
255 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
256 ret = RESUME_HOST;
257 }
258 return ret;
259 }
260
kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu * vcpu)261 static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
262 {
263 struct kvm_run *run = vcpu->run;
264 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
265 unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
266 unsigned long cause = vcpu->arch.host_cp0_cause;
267 enum emulation_result er = EMULATE_DONE;
268 int ret = RESUME_GUEST;
269
270 if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
271 #ifdef DEBUG
272 kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
273 #endif
274 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
275 if (er == EMULATE_FAIL) {
276 printk("Emulate Load from MMIO space failed\n");
277 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
278 ret = RESUME_HOST;
279 } else {
280 run->exit_reason = KVM_EXIT_MMIO;
281 ret = RESUME_HOST;
282 }
283 } else {
284 printk
285 ("Address Error (LOAD): cause %#lx, PC: %p, BadVaddr: %#lx\n",
286 cause, opc, badvaddr);
287 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
288 ret = RESUME_HOST;
289 er = EMULATE_FAIL;
290 }
291 return ret;
292 }
293
kvm_trap_emul_handle_syscall(struct kvm_vcpu * vcpu)294 static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
295 {
296 struct kvm_run *run = vcpu->run;
297 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
298 unsigned long cause = vcpu->arch.host_cp0_cause;
299 enum emulation_result er = EMULATE_DONE;
300 int ret = RESUME_GUEST;
301
302 er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
303 if (er == EMULATE_DONE)
304 ret = RESUME_GUEST;
305 else {
306 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
307 ret = RESUME_HOST;
308 }
309 return ret;
310 }
311
kvm_trap_emul_handle_res_inst(struct kvm_vcpu * vcpu)312 static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
313 {
314 struct kvm_run *run = vcpu->run;
315 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
316 unsigned long cause = vcpu->arch.host_cp0_cause;
317 enum emulation_result er = EMULATE_DONE;
318 int ret = RESUME_GUEST;
319
320 er = kvm_mips_handle_ri(cause, opc, run, vcpu);
321 if (er == EMULATE_DONE)
322 ret = RESUME_GUEST;
323 else {
324 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
325 ret = RESUME_HOST;
326 }
327 return ret;
328 }
329
kvm_trap_emul_handle_break(struct kvm_vcpu * vcpu)330 static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
331 {
332 struct kvm_run *run = vcpu->run;
333 uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
334 unsigned long cause = vcpu->arch.host_cp0_cause;
335 enum emulation_result er = EMULATE_DONE;
336 int ret = RESUME_GUEST;
337
338 er = kvm_mips_emulate_bp_exc(cause, opc, run, vcpu);
339 if (er == EMULATE_DONE)
340 ret = RESUME_GUEST;
341 else {
342 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
343 ret = RESUME_HOST;
344 }
345 return ret;
346 }
347
kvm_trap_emul_vm_init(struct kvm * kvm)348 static int kvm_trap_emul_vm_init(struct kvm *kvm)
349 {
350 return 0;
351 }
352
kvm_trap_emul_vcpu_init(struct kvm_vcpu * vcpu)353 static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
354 {
355 return 0;
356 }
357
kvm_trap_emul_vcpu_setup(struct kvm_vcpu * vcpu)358 static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
359 {
360 struct mips_coproc *cop0 = vcpu->arch.cop0;
361 uint32_t config1;
362 int vcpu_id = vcpu->vcpu_id;
363
364 /* Arch specific stuff, set up config registers properly so that the
365 * guest will come up as expected, for now we simulate a
366 * MIPS 24kc
367 */
368 kvm_write_c0_guest_prid(cop0, 0x00019300);
369 kvm_write_c0_guest_config(cop0,
370 MIPS_CONFIG0 | (0x1 << CP0C0_AR) |
371 (MMU_TYPE_R4000 << CP0C0_MT));
372
373 /* Read the cache characteristics from the host Config1 Register */
374 config1 = (read_c0_config1() & ~0x7f);
375
376 /* Set up MMU size */
377 config1 &= ~(0x3f << 25);
378 config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
379
380 /* We unset some bits that we aren't emulating */
381 config1 &=
382 ~((1 << CP0C1_C2) | (1 << CP0C1_MD) | (1 << CP0C1_PC) |
383 (1 << CP0C1_WR) | (1 << CP0C1_CA));
384 kvm_write_c0_guest_config1(cop0, config1);
385
386 kvm_write_c0_guest_config2(cop0, MIPS_CONFIG2);
387 /* MIPS_CONFIG2 | (read_c0_config2() & 0xfff) */
388 kvm_write_c0_guest_config3(cop0,
389 MIPS_CONFIG3 | (0 << CP0C3_VInt) | (1 <<
390 CP0C3_ULRI));
391
392 /* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
393 kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
394
395 /* Setup IntCtl defaults, compatibilty mode for timer interrupts (HW5) */
396 kvm_write_c0_guest_intctl(cop0, 0xFC000000);
397
398 /* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
399 kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 | (vcpu_id & 0xFF));
400
401 return 0;
402 }
403
404 static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
405 /* exit handlers */
406 .handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
407 .handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
408 .handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
409 .handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
410 .handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
411 .handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
412 .handle_syscall = kvm_trap_emul_handle_syscall,
413 .handle_res_inst = kvm_trap_emul_handle_res_inst,
414 .handle_break = kvm_trap_emul_handle_break,
415
416 .vm_init = kvm_trap_emul_vm_init,
417 .vcpu_init = kvm_trap_emul_vcpu_init,
418 .vcpu_setup = kvm_trap_emul_vcpu_setup,
419 .gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
420 .queue_timer_int = kvm_mips_queue_timer_int_cb,
421 .dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
422 .queue_io_int = kvm_mips_queue_io_int_cb,
423 .dequeue_io_int = kvm_mips_dequeue_io_int_cb,
424 .irq_deliver = kvm_mips_irq_deliver_cb,
425 .irq_clear = kvm_mips_irq_clear_cb,
426 };
427
kvm_mips_emulation_init(struct kvm_mips_callbacks ** install_callbacks)428 int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
429 {
430 *install_callbacks = &kvm_trap_emul_callbacks;
431 return 0;
432 }
433