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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/vmalloc.h>
15 
16 #include <linux/kvm_host.h>
17 
18 #include "interrupt.h"
19 
kvm_trap_emul_gva_to_gpa_cb(gva_t gva)20 static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
21 {
22 	gpa_t gpa;
23 	gva_t kseg = KSEGX(gva);
24 
25 	if ((kseg == CKSEG0) || (kseg == CKSEG1))
26 		gpa = CPHYSADDR(gva);
27 	else {
28 		kvm_err("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
29 		kvm_mips_dump_host_tlbs();
30 		gpa = KVM_INVALID_ADDR;
31 	}
32 
33 	kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
34 
35 	return gpa;
36 }
37 
kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu * vcpu)38 static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
39 {
40 	struct mips_coproc *cop0 = vcpu->arch.cop0;
41 	struct kvm_run *run = vcpu->run;
42 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
43 	u32 cause = vcpu->arch.host_cp0_cause;
44 	enum emulation_result er = EMULATE_DONE;
45 	int ret = RESUME_GUEST;
46 
47 	if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
48 		/* FPU Unusable */
49 		if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
50 		    (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
51 			/*
52 			 * Unusable/no FPU in guest:
53 			 * deliver guest COP1 Unusable Exception
54 			 */
55 			er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
56 		} else {
57 			/* Restore FPU state */
58 			kvm_own_fpu(vcpu);
59 			er = EMULATE_DONE;
60 		}
61 	} else {
62 		er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
63 	}
64 
65 	switch (er) {
66 	case EMULATE_DONE:
67 		ret = RESUME_GUEST;
68 		break;
69 
70 	case EMULATE_FAIL:
71 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
72 		ret = RESUME_HOST;
73 		break;
74 
75 	case EMULATE_WAIT:
76 		run->exit_reason = KVM_EXIT_INTR;
77 		ret = RESUME_HOST;
78 		break;
79 
80 	default:
81 		BUG();
82 	}
83 	return ret;
84 }
85 
kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu * vcpu)86 static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
87 {
88 	struct kvm_run *run = vcpu->run;
89 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
90 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
91 	u32 cause = vcpu->arch.host_cp0_cause;
92 	enum emulation_result er = EMULATE_DONE;
93 	int ret = RESUME_GUEST;
94 
95 	if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
96 	    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
97 		kvm_debug("USER/KSEG23 ADDR TLB MOD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
98 			  cause, opc, badvaddr);
99 		er = kvm_mips_handle_tlbmod(cause, opc, run, vcpu);
100 
101 		if (er == EMULATE_DONE)
102 			ret = RESUME_GUEST;
103 		else {
104 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
105 			ret = RESUME_HOST;
106 		}
107 	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
108 		/*
109 		 * XXXKYMA: The guest kernel does not expect to get this fault
110 		 * when we are not using HIGHMEM. Need to address this in a
111 		 * HIGHMEM kernel
112 		 */
113 		kvm_err("TLB MOD fault not handled, cause %#x, PC: %p, BadVaddr: %#lx\n",
114 			cause, opc, badvaddr);
115 		kvm_mips_dump_host_tlbs();
116 		kvm_arch_vcpu_dump_regs(vcpu);
117 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
118 		ret = RESUME_HOST;
119 	} else {
120 		kvm_err("Illegal TLB Mod fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
121 			cause, opc, badvaddr);
122 		kvm_mips_dump_host_tlbs();
123 		kvm_arch_vcpu_dump_regs(vcpu);
124 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
125 		ret = RESUME_HOST;
126 	}
127 	return ret;
128 }
129 
kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu * vcpu,bool store)130 static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
131 {
132 	struct kvm_run *run = vcpu->run;
133 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
134 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
135 	u32 cause = vcpu->arch.host_cp0_cause;
136 	enum emulation_result er = EMULATE_DONE;
137 	int ret = RESUME_GUEST;
138 
139 	if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
140 	    && KVM_GUEST_KERNEL_MODE(vcpu)) {
141 		if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
142 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
143 			ret = RESUME_HOST;
144 		}
145 	} else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
146 		   || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
147 		kvm_debug("USER ADDR TLB %s fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
148 			  store ? "ST" : "LD", cause, opc, badvaddr);
149 
150 		/*
151 		 * User Address (UA) fault, this could happen if
152 		 * (1) TLB entry not present/valid in both Guest and shadow host
153 		 *     TLBs, in this case we pass on the fault to the guest
154 		 *     kernel and let it handle it.
155 		 * (2) TLB entry is present in the Guest TLB but not in the
156 		 *     shadow, in this case we inject the TLB from the Guest TLB
157 		 *     into the shadow host TLB
158 		 */
159 
160 		er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
161 		if (er == EMULATE_DONE)
162 			ret = RESUME_GUEST;
163 		else {
164 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
165 			ret = RESUME_HOST;
166 		}
167 	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
168 		/*
169 		 * All KSEG0 faults are handled by KVM, as the guest kernel does
170 		 * not expect to ever get them
171 		 */
172 		if (kvm_mips_handle_kseg0_tlb_fault
173 		    (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
174 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
175 			ret = RESUME_HOST;
176 		}
177 	} else if (KVM_GUEST_KERNEL_MODE(vcpu)
178 		   && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
179 		/*
180 		 * With EVA we may get a TLB exception instead of an address
181 		 * error when the guest performs MMIO to KSeg1 addresses.
182 		 */
183 		kvm_debug("Emulate %s MMIO space\n",
184 			  store ? "Store to" : "Load from");
185 		er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
186 		if (er == EMULATE_FAIL) {
187 			kvm_err("Emulate %s MMIO space failed\n",
188 				store ? "Store to" : "Load from");
189 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
190 			ret = RESUME_HOST;
191 		} else {
192 			run->exit_reason = KVM_EXIT_MMIO;
193 			ret = RESUME_HOST;
194 		}
195 	} else {
196 		kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
197 			store ? "ST" : "LD", cause, opc, badvaddr);
198 		kvm_mips_dump_host_tlbs();
199 		kvm_arch_vcpu_dump_regs(vcpu);
200 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
201 		ret = RESUME_HOST;
202 	}
203 	return ret;
204 }
205 
kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu * vcpu)206 static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
207 {
208 	return kvm_trap_emul_handle_tlb_miss(vcpu, true);
209 }
210 
kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu * vcpu)211 static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
212 {
213 	return kvm_trap_emul_handle_tlb_miss(vcpu, false);
214 }
215 
kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu * vcpu)216 static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
217 {
218 	struct kvm_run *run = vcpu->run;
219 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
220 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
221 	u32 cause = vcpu->arch.host_cp0_cause;
222 	enum emulation_result er = EMULATE_DONE;
223 	int ret = RESUME_GUEST;
224 
225 	if (KVM_GUEST_KERNEL_MODE(vcpu)
226 	    && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
227 		kvm_debug("Emulate Store to MMIO space\n");
228 		er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
229 		if (er == EMULATE_FAIL) {
230 			kvm_err("Emulate Store to MMIO space failed\n");
231 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
232 			ret = RESUME_HOST;
233 		} else {
234 			run->exit_reason = KVM_EXIT_MMIO;
235 			ret = RESUME_HOST;
236 		}
237 	} else {
238 		kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
239 			cause, opc, badvaddr);
240 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
241 		ret = RESUME_HOST;
242 	}
243 	return ret;
244 }
245 
kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu * vcpu)246 static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
247 {
248 	struct kvm_run *run = vcpu->run;
249 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
250 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
251 	u32 cause = vcpu->arch.host_cp0_cause;
252 	enum emulation_result er = EMULATE_DONE;
253 	int ret = RESUME_GUEST;
254 
255 	if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
256 		kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
257 		er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
258 		if (er == EMULATE_FAIL) {
259 			kvm_err("Emulate Load from MMIO space failed\n");
260 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
261 			ret = RESUME_HOST;
262 		} else {
263 			run->exit_reason = KVM_EXIT_MMIO;
264 			ret = RESUME_HOST;
265 		}
266 	} else {
267 		kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
268 			cause, opc, badvaddr);
269 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
270 		ret = RESUME_HOST;
271 		er = EMULATE_FAIL;
272 	}
273 	return ret;
274 }
275 
kvm_trap_emul_handle_syscall(struct kvm_vcpu * vcpu)276 static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
277 {
278 	struct kvm_run *run = vcpu->run;
279 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
280 	u32 cause = vcpu->arch.host_cp0_cause;
281 	enum emulation_result er = EMULATE_DONE;
282 	int ret = RESUME_GUEST;
283 
284 	er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
285 	if (er == EMULATE_DONE)
286 		ret = RESUME_GUEST;
287 	else {
288 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
289 		ret = RESUME_HOST;
290 	}
291 	return ret;
292 }
293 
kvm_trap_emul_handle_res_inst(struct kvm_vcpu * vcpu)294 static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
295 {
296 	struct kvm_run *run = vcpu->run;
297 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
298 	u32 cause = vcpu->arch.host_cp0_cause;
299 	enum emulation_result er = EMULATE_DONE;
300 	int ret = RESUME_GUEST;
301 
302 	er = kvm_mips_handle_ri(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_break(struct kvm_vcpu * vcpu)312 static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
313 {
314 	struct kvm_run *run = vcpu->run;
315 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
316 	u32 cause = vcpu->arch.host_cp0_cause;
317 	enum emulation_result er = EMULATE_DONE;
318 	int ret = RESUME_GUEST;
319 
320 	er = kvm_mips_emulate_bp_exc(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_trap(struct kvm_vcpu * vcpu)330 static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
331 {
332 	struct kvm_run *run = vcpu->run;
333 	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
334 	u32 cause = vcpu->arch.host_cp0_cause;
335 	enum emulation_result er = EMULATE_DONE;
336 	int ret = RESUME_GUEST;
337 
338 	er = kvm_mips_emulate_trap_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_handle_msa_fpe(struct kvm_vcpu * vcpu)348 static int kvm_trap_emul_handle_msa_fpe(struct kvm_vcpu *vcpu)
349 {
350 	struct kvm_run *run = vcpu->run;
351 	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
352 	u32 cause = vcpu->arch.host_cp0_cause;
353 	enum emulation_result er = EMULATE_DONE;
354 	int ret = RESUME_GUEST;
355 
356 	er = kvm_mips_emulate_msafpe_exc(cause, opc, run, vcpu);
357 	if (er == EMULATE_DONE) {
358 		ret = RESUME_GUEST;
359 	} else {
360 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
361 		ret = RESUME_HOST;
362 	}
363 	return ret;
364 }
365 
kvm_trap_emul_handle_fpe(struct kvm_vcpu * vcpu)366 static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
367 {
368 	struct kvm_run *run = vcpu->run;
369 	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
370 	u32 cause = vcpu->arch.host_cp0_cause;
371 	enum emulation_result er = EMULATE_DONE;
372 	int ret = RESUME_GUEST;
373 
374 	er = kvm_mips_emulate_fpe_exc(cause, opc, run, vcpu);
375 	if (er == EMULATE_DONE) {
376 		ret = RESUME_GUEST;
377 	} else {
378 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
379 		ret = RESUME_HOST;
380 	}
381 	return ret;
382 }
383 
384 /**
385  * kvm_trap_emul_handle_msa_disabled() - Guest used MSA while disabled in root.
386  * @vcpu:	Virtual CPU context.
387  *
388  * Handle when the guest attempts to use MSA when it is disabled.
389  */
kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu * vcpu)390 static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
391 {
392 	struct mips_coproc *cop0 = vcpu->arch.cop0;
393 	struct kvm_run *run = vcpu->run;
394 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
395 	u32 cause = vcpu->arch.host_cp0_cause;
396 	enum emulation_result er = EMULATE_DONE;
397 	int ret = RESUME_GUEST;
398 
399 	if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
400 	    (kvm_read_c0_guest_status(cop0) & (ST0_CU1 | ST0_FR)) == ST0_CU1) {
401 		/*
402 		 * No MSA in guest, or FPU enabled and not in FR=1 mode,
403 		 * guest reserved instruction exception
404 		 */
405 		er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
406 	} else if (!(kvm_read_c0_guest_config5(cop0) & MIPS_CONF5_MSAEN)) {
407 		/* MSA disabled by guest, guest MSA disabled exception */
408 		er = kvm_mips_emulate_msadis_exc(cause, opc, run, vcpu);
409 	} else {
410 		/* Restore MSA/FPU state */
411 		kvm_own_msa(vcpu);
412 		er = EMULATE_DONE;
413 	}
414 
415 	switch (er) {
416 	case EMULATE_DONE:
417 		ret = RESUME_GUEST;
418 		break;
419 
420 	case EMULATE_FAIL:
421 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
422 		ret = RESUME_HOST;
423 		break;
424 
425 	default:
426 		BUG();
427 	}
428 	return ret;
429 }
430 
kvm_trap_emul_vm_init(struct kvm * kvm)431 static int kvm_trap_emul_vm_init(struct kvm *kvm)
432 {
433 	return 0;
434 }
435 
kvm_trap_emul_vcpu_init(struct kvm_vcpu * vcpu)436 static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
437 {
438 	vcpu->arch.kscratch_enabled = 0xfc;
439 
440 	return 0;
441 }
442 
kvm_trap_emul_vcpu_setup(struct kvm_vcpu * vcpu)443 static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
444 {
445 	struct mips_coproc *cop0 = vcpu->arch.cop0;
446 	u32 config, config1;
447 	int vcpu_id = vcpu->vcpu_id;
448 
449 	/*
450 	 * Arch specific stuff, set up config registers properly so that the
451 	 * guest will come up as expected
452 	 */
453 #ifndef CONFIG_CPU_MIPSR6
454 	/* r2-r5, simulate a MIPS 24kc */
455 	kvm_write_c0_guest_prid(cop0, 0x00019300);
456 #else
457 	/* r6+, simulate a generic QEMU machine */
458 	kvm_write_c0_guest_prid(cop0, 0x00010000);
459 #endif
460 	/*
461 	 * Have config1, Cacheable, noncoherent, write-back, write allocate.
462 	 * Endianness, arch revision & virtually tagged icache should match
463 	 * host.
464 	 */
465 	config = read_c0_config() & MIPS_CONF_AR;
466 	config |= MIPS_CONF_M | CONF_CM_CACHABLE_NONCOHERENT | MIPS_CONF_MT_TLB;
467 #ifdef CONFIG_CPU_BIG_ENDIAN
468 	config |= CONF_BE;
469 #endif
470 	if (cpu_has_vtag_icache)
471 		config |= MIPS_CONF_VI;
472 	kvm_write_c0_guest_config(cop0, config);
473 
474 	/* Read the cache characteristics from the host Config1 Register */
475 	config1 = (read_c0_config1() & ~0x7f);
476 
477 	/* Set up MMU size */
478 	config1 &= ~(0x3f << 25);
479 	config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
480 
481 	/* We unset some bits that we aren't emulating */
482 	config1 &= ~(MIPS_CONF1_C2 | MIPS_CONF1_MD | MIPS_CONF1_PC |
483 		     MIPS_CONF1_WR | MIPS_CONF1_CA);
484 	kvm_write_c0_guest_config1(cop0, config1);
485 
486 	/* Have config3, no tertiary/secondary caches implemented */
487 	kvm_write_c0_guest_config2(cop0, MIPS_CONF_M);
488 	/* MIPS_CONF_M | (read_c0_config2() & 0xfff) */
489 
490 	/* Have config4, UserLocal */
491 	kvm_write_c0_guest_config3(cop0, MIPS_CONF_M | MIPS_CONF3_ULRI);
492 
493 	/* Have config5 */
494 	kvm_write_c0_guest_config4(cop0, MIPS_CONF_M);
495 
496 	/* No config6 */
497 	kvm_write_c0_guest_config5(cop0, 0);
498 
499 	/* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
500 	kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
501 
502 	/*
503 	 * Setup IntCtl defaults, compatibility mode for timer interrupts (HW5)
504 	 */
505 	kvm_write_c0_guest_intctl(cop0, 0xFC000000);
506 
507 	/* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
508 	kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 |
509 				       (vcpu_id & MIPS_EBASE_CPUNUM));
510 
511 	return 0;
512 }
513 
kvm_trap_emul_num_regs(struct kvm_vcpu * vcpu)514 static unsigned long kvm_trap_emul_num_regs(struct kvm_vcpu *vcpu)
515 {
516 	return 0;
517 }
518 
kvm_trap_emul_copy_reg_indices(struct kvm_vcpu * vcpu,u64 __user * indices)519 static int kvm_trap_emul_copy_reg_indices(struct kvm_vcpu *vcpu,
520 					  u64 __user *indices)
521 {
522 	return 0;
523 }
524 
kvm_trap_emul_get_one_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg,s64 * v)525 static int kvm_trap_emul_get_one_reg(struct kvm_vcpu *vcpu,
526 				     const struct kvm_one_reg *reg,
527 				     s64 *v)
528 {
529 	switch (reg->id) {
530 	case KVM_REG_MIPS_CP0_COUNT:
531 		*v = kvm_mips_read_count(vcpu);
532 		break;
533 	case KVM_REG_MIPS_COUNT_CTL:
534 		*v = vcpu->arch.count_ctl;
535 		break;
536 	case KVM_REG_MIPS_COUNT_RESUME:
537 		*v = ktime_to_ns(vcpu->arch.count_resume);
538 		break;
539 	case KVM_REG_MIPS_COUNT_HZ:
540 		*v = vcpu->arch.count_hz;
541 		break;
542 	default:
543 		return -EINVAL;
544 	}
545 	return 0;
546 }
547 
kvm_trap_emul_set_one_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg,s64 v)548 static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
549 				     const struct kvm_one_reg *reg,
550 				     s64 v)
551 {
552 	struct mips_coproc *cop0 = vcpu->arch.cop0;
553 	int ret = 0;
554 	unsigned int cur, change;
555 
556 	switch (reg->id) {
557 	case KVM_REG_MIPS_CP0_COUNT:
558 		kvm_mips_write_count(vcpu, v);
559 		break;
560 	case KVM_REG_MIPS_CP0_COMPARE:
561 		kvm_mips_write_compare(vcpu, v, false);
562 		break;
563 	case KVM_REG_MIPS_CP0_CAUSE:
564 		/*
565 		 * If the timer is stopped or started (DC bit) it must look
566 		 * atomic with changes to the interrupt pending bits (TI, IRQ5).
567 		 * A timer interrupt should not happen in between.
568 		 */
569 		if ((kvm_read_c0_guest_cause(cop0) ^ v) & CAUSEF_DC) {
570 			if (v & CAUSEF_DC) {
571 				/* disable timer first */
572 				kvm_mips_count_disable_cause(vcpu);
573 				kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
574 			} else {
575 				/* enable timer last */
576 				kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
577 				kvm_mips_count_enable_cause(vcpu);
578 			}
579 		} else {
580 			kvm_write_c0_guest_cause(cop0, v);
581 		}
582 		break;
583 	case KVM_REG_MIPS_CP0_CONFIG:
584 		/* read-only for now */
585 		break;
586 	case KVM_REG_MIPS_CP0_CONFIG1:
587 		cur = kvm_read_c0_guest_config1(cop0);
588 		change = (cur ^ v) & kvm_mips_config1_wrmask(vcpu);
589 		if (change) {
590 			v = cur ^ change;
591 			kvm_write_c0_guest_config1(cop0, v);
592 		}
593 		break;
594 	case KVM_REG_MIPS_CP0_CONFIG2:
595 		/* read-only for now */
596 		break;
597 	case KVM_REG_MIPS_CP0_CONFIG3:
598 		cur = kvm_read_c0_guest_config3(cop0);
599 		change = (cur ^ v) & kvm_mips_config3_wrmask(vcpu);
600 		if (change) {
601 			v = cur ^ change;
602 			kvm_write_c0_guest_config3(cop0, v);
603 		}
604 		break;
605 	case KVM_REG_MIPS_CP0_CONFIG4:
606 		cur = kvm_read_c0_guest_config4(cop0);
607 		change = (cur ^ v) & kvm_mips_config4_wrmask(vcpu);
608 		if (change) {
609 			v = cur ^ change;
610 			kvm_write_c0_guest_config4(cop0, v);
611 		}
612 		break;
613 	case KVM_REG_MIPS_CP0_CONFIG5:
614 		cur = kvm_read_c0_guest_config5(cop0);
615 		change = (cur ^ v) & kvm_mips_config5_wrmask(vcpu);
616 		if (change) {
617 			v = cur ^ change;
618 			kvm_write_c0_guest_config5(cop0, v);
619 		}
620 		break;
621 	case KVM_REG_MIPS_COUNT_CTL:
622 		ret = kvm_mips_set_count_ctl(vcpu, v);
623 		break;
624 	case KVM_REG_MIPS_COUNT_RESUME:
625 		ret = kvm_mips_set_count_resume(vcpu, v);
626 		break;
627 	case KVM_REG_MIPS_COUNT_HZ:
628 		ret = kvm_mips_set_count_hz(vcpu, v);
629 		break;
630 	default:
631 		return -EINVAL;
632 	}
633 	return ret;
634 }
635 
kvm_trap_emul_vcpu_get_regs(struct kvm_vcpu * vcpu)636 static int kvm_trap_emul_vcpu_get_regs(struct kvm_vcpu *vcpu)
637 {
638 	kvm_lose_fpu(vcpu);
639 
640 	return 0;
641 }
642 
kvm_trap_emul_vcpu_set_regs(struct kvm_vcpu * vcpu)643 static int kvm_trap_emul_vcpu_set_regs(struct kvm_vcpu *vcpu)
644 {
645 	return 0;
646 }
647 
648 static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
649 	/* exit handlers */
650 	.handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
651 	.handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
652 	.handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
653 	.handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
654 	.handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
655 	.handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
656 	.handle_syscall = kvm_trap_emul_handle_syscall,
657 	.handle_res_inst = kvm_trap_emul_handle_res_inst,
658 	.handle_break = kvm_trap_emul_handle_break,
659 	.handle_trap = kvm_trap_emul_handle_trap,
660 	.handle_msa_fpe = kvm_trap_emul_handle_msa_fpe,
661 	.handle_fpe = kvm_trap_emul_handle_fpe,
662 	.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
663 
664 	.vm_init = kvm_trap_emul_vm_init,
665 	.vcpu_init = kvm_trap_emul_vcpu_init,
666 	.vcpu_setup = kvm_trap_emul_vcpu_setup,
667 	.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
668 	.queue_timer_int = kvm_mips_queue_timer_int_cb,
669 	.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
670 	.queue_io_int = kvm_mips_queue_io_int_cb,
671 	.dequeue_io_int = kvm_mips_dequeue_io_int_cb,
672 	.irq_deliver = kvm_mips_irq_deliver_cb,
673 	.irq_clear = kvm_mips_irq_clear_cb,
674 	.num_regs = kvm_trap_emul_num_regs,
675 	.copy_reg_indices = kvm_trap_emul_copy_reg_indices,
676 	.get_one_reg = kvm_trap_emul_get_one_reg,
677 	.set_one_reg = kvm_trap_emul_set_one_reg,
678 	.vcpu_get_regs = kvm_trap_emul_vcpu_get_regs,
679 	.vcpu_set_regs = kvm_trap_emul_vcpu_set_regs,
680 };
681 
kvm_mips_emulation_init(struct kvm_mips_callbacks ** install_callbacks)682 int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
683 {
684 	*install_callbacks = &kvm_trap_emul_callbacks;
685 	return 0;
686 }
687