xref: /linux/arch/loongarch/kvm/exit.c (revision bba2c3615bd6cfee7456d1130f2e6b01b3f4e9ba)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
4  */
5 
6 #include <linux/err.h>
7 #include <linux/errno.h>
8 #include <linux/kvm_host.h>
9 #include <linux/module.h>
10 #include <linux/preempt.h>
11 #include <linux/vmalloc.h>
12 #include <trace/events/kvm.h>
13 #include <asm/fpu.h>
14 #include <asm/inst.h>
15 #include <asm/loongarch.h>
16 #include <asm/mmzone.h>
17 #include <asm/numa.h>
18 #include <asm/time.h>
19 #include <asm/tlb.h>
20 #include <asm/kvm_csr.h>
21 #include <asm/kvm_vcpu.h>
22 #include "trace.h"
23 
24 static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst)
25 {
26 	int rd, rj;
27 	unsigned int index, ret;
28 
29 	if (inst.reg2_format.opcode != cpucfg_op)
30 		return EMULATE_FAIL;
31 
32 	rd = inst.reg2_format.rd;
33 	rj = inst.reg2_format.rj;
34 	++vcpu->stat.cpucfg_exits;
35 	index = vcpu->arch.gprs[rj];
36 
37 	/*
38 	 * By LoongArch Reference Manual 2.2.10.5
39 	 * Return value is 0 for undefined CPUCFG index
40 	 *
41 	 * Disable preemption since hw gcsr is accessed
42 	 */
43 	preempt_disable();
44 	switch (index) {
45 	case 0 ... (KVM_MAX_CPUCFG_REGS - 1):
46 		vcpu->arch.gprs[rd] = vcpu->arch.cpucfg[index];
47 		break;
48 	case CPUCFG_KVM_SIG:
49 		/* CPUCFG emulation between 0x40000000 -- 0x400000ff */
50 		vcpu->arch.gprs[rd] = *(unsigned int *)KVM_SIGNATURE;
51 		break;
52 	case CPUCFG_KVM_FEATURE:
53 		ret = vcpu->kvm->arch.pv_features & LOONGARCH_PV_FEAT_MASK;
54 		vcpu->arch.gprs[rd] = ret;
55 		break;
56 	default:
57 		vcpu->arch.gprs[rd] = 0;
58 		break;
59 	}
60 	preempt_enable();
61 
62 	return EMULATE_DONE;
63 }
64 
65 static unsigned long kvm_emu_read_csr(struct kvm_vcpu *vcpu, int csrid)
66 {
67 	unsigned long val = 0;
68 	struct loongarch_csrs *csr = vcpu->arch.csr;
69 
70 	/*
71 	 * From LoongArch Reference Manual Volume 1 Chapter 4.2.1
72 	 * For undefined CSR id, return value is 0
73 	 */
74 	if (get_gcsr_flag(csrid) & SW_GCSR)
75 		val = kvm_read_sw_gcsr(csr, csrid);
76 	else
77 		pr_warn_once("Unsupported csrrd 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
78 
79 	return val;
80 }
81 
82 static unsigned long kvm_emu_write_csr(struct kvm_vcpu *vcpu, int csrid, unsigned long val)
83 {
84 	unsigned long old = 0;
85 	struct loongarch_csrs *csr = vcpu->arch.csr;
86 
87 	if (get_gcsr_flag(csrid) & SW_GCSR) {
88 		old = kvm_read_sw_gcsr(csr, csrid);
89 		kvm_write_sw_gcsr(csr, csrid, val);
90 	} else
91 		pr_warn_once("Unsupported csrwr 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
92 
93 	return old;
94 }
95 
96 static unsigned long kvm_emu_xchg_csr(struct kvm_vcpu *vcpu, int csrid,
97 				unsigned long csr_mask, unsigned long val)
98 {
99 	unsigned long old = 0;
100 	struct loongarch_csrs *csr = vcpu->arch.csr;
101 
102 	if (get_gcsr_flag(csrid) & SW_GCSR) {
103 		old = kvm_read_sw_gcsr(csr, csrid);
104 		val = (old & ~csr_mask) | (val & csr_mask);
105 		kvm_write_sw_gcsr(csr, csrid, val);
106 	} else
107 		pr_warn_once("Unsupported csrxchg 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
108 
109 	return old;
110 }
111 
112 static int kvm_handle_csr(struct kvm_vcpu *vcpu, larch_inst inst)
113 {
114 	unsigned int rd, rj, csrid;
115 	unsigned long csr_mask, val = 0;
116 
117 	/*
118 	 * CSR value mask imm
119 	 * rj = 0 means csrrd
120 	 * rj = 1 means csrwr
121 	 * rj != 0,1 means csrxchg
122 	 */
123 	rd = inst.reg2csr_format.rd;
124 	rj = inst.reg2csr_format.rj;
125 	csrid = inst.reg2csr_format.csr;
126 
127 	if (csrid >= LOONGARCH_CSR_PERFCTRL0 && csrid <= vcpu->arch.max_pmu_csrid) {
128 		if (kvm_guest_has_pmu(&vcpu->arch)) {
129 			vcpu->arch.pc -= 4;
130 			kvm_make_request(KVM_REQ_PMU, vcpu);
131 			return EMULATE_DONE;
132 		}
133 	}
134 
135 	/* Process CSR ops */
136 	switch (rj) {
137 	case 0: /* process csrrd */
138 		val = kvm_emu_read_csr(vcpu, csrid);
139 		vcpu->arch.gprs[rd] = val;
140 		break;
141 	case 1: /* process csrwr */
142 		val = vcpu->arch.gprs[rd];
143 		val = kvm_emu_write_csr(vcpu, csrid, val);
144 		vcpu->arch.gprs[rd] = val;
145 		break;
146 	default: /* process csrxchg */
147 		val = vcpu->arch.gprs[rd];
148 		csr_mask = vcpu->arch.gprs[rj];
149 		val = kvm_emu_xchg_csr(vcpu, csrid, csr_mask, val);
150 		vcpu->arch.gprs[rd] = val;
151 	}
152 
153 	return EMULATE_DONE;
154 }
155 
156 int kvm_emu_iocsr(larch_inst inst, struct kvm_run *run, struct kvm_vcpu *vcpu)
157 {
158 	int idx, ret;
159 	unsigned long *val;
160 	u32 addr, rd, rj, opcode;
161 
162 	/*
163 	 * Each IOCSR with different opcode
164 	 */
165 	rd = inst.reg2_format.rd;
166 	rj = inst.reg2_format.rj;
167 	opcode = inst.reg2_format.opcode;
168 	addr = vcpu->arch.gprs[rj];
169 	run->iocsr_io.phys_addr = addr;
170 	run->iocsr_io.is_write = 0;
171 	val = &vcpu->arch.gprs[rd];
172 
173 	/* LoongArch is Little endian */
174 	switch (opcode) {
175 	case iocsrrdb_op:
176 		run->iocsr_io.len = 1;
177 		break;
178 	case iocsrrdh_op:
179 		run->iocsr_io.len = 2;
180 		break;
181 	case iocsrrdw_op:
182 		run->iocsr_io.len = 4;
183 		break;
184 	case iocsrrdd_op:
185 		run->iocsr_io.len = 8;
186 		break;
187 	case iocsrwrb_op:
188 		run->iocsr_io.len = 1;
189 		run->iocsr_io.is_write = 1;
190 		break;
191 	case iocsrwrh_op:
192 		run->iocsr_io.len = 2;
193 		run->iocsr_io.is_write = 1;
194 		break;
195 	case iocsrwrw_op:
196 		run->iocsr_io.len = 4;
197 		run->iocsr_io.is_write = 1;
198 		break;
199 	case iocsrwrd_op:
200 		run->iocsr_io.len = 8;
201 		run->iocsr_io.is_write = 1;
202 		break;
203 	default:
204 		return EMULATE_FAIL;
205 	}
206 
207 	if (run->iocsr_io.is_write) {
208 		idx = srcu_read_lock(&vcpu->kvm->srcu);
209 		ret = kvm_io_bus_write(vcpu, KVM_IOCSR_BUS, addr, run->iocsr_io.len, val);
210 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
211 		if (ret == 0)
212 			ret = EMULATE_DONE;
213 		else {
214 			ret = EMULATE_DO_IOCSR;
215 			/* Save data and let user space to write it */
216 			memcpy(run->iocsr_io.data, val, run->iocsr_io.len);
217 		}
218 		trace_kvm_iocsr(KVM_TRACE_IOCSR_WRITE, run->iocsr_io.len, addr, val);
219 	} else {
220 		vcpu->arch.io_gpr = rd; /* Set register id for iocsr read completion */
221 		idx = srcu_read_lock(&vcpu->kvm->srcu);
222 		ret = kvm_io_bus_read(vcpu, KVM_IOCSR_BUS, addr,
223 				      run->iocsr_io.len, run->iocsr_io.data);
224 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
225 		if (ret == 0) {
226 			kvm_complete_iocsr_read(vcpu, run);
227 			ret = EMULATE_DONE;
228 		} else
229 			ret = EMULATE_DO_IOCSR;
230 		trace_kvm_iocsr(KVM_TRACE_IOCSR_READ, run->iocsr_io.len, addr, NULL);
231 	}
232 
233 	return ret;
234 }
235 
236 int kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
237 {
238 	enum emulation_result er = EMULATE_DONE;
239 	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
240 
241 	switch (run->iocsr_io.len) {
242 	case 1:
243 		*gpr = *(s8 *)run->iocsr_io.data;
244 		break;
245 	case 2:
246 		*gpr = *(s16 *)run->iocsr_io.data;
247 		break;
248 	case 4:
249 		*gpr = *(s32 *)run->iocsr_io.data;
250 		break;
251 	case 8:
252 		*gpr = *(s64 *)run->iocsr_io.data;
253 		break;
254 	default:
255 		kvm_err("Bad IOCSR length: %d, addr is 0x%lx\n",
256 				run->iocsr_io.len, vcpu->arch.badv);
257 		er = EMULATE_FAIL;
258 		break;
259 	}
260 
261 	return er;
262 }
263 
264 int kvm_emu_idle(struct kvm_vcpu *vcpu)
265 {
266 	++vcpu->stat.idle_exits;
267 	trace_kvm_exit_idle(vcpu, KVM_TRACE_EXIT_IDLE);
268 
269 	if (!kvm_arch_vcpu_runnable(vcpu))
270 		kvm_vcpu_halt(vcpu);
271 
272 	return EMULATE_DONE;
273 }
274 
275 static int kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)
276 {
277 	unsigned long curr_pc;
278 	larch_inst inst;
279 	enum emulation_result er = EMULATE_DONE;
280 	struct kvm_run *run = vcpu->run;
281 
282 	/* Fetch the instruction */
283 	inst.word = vcpu->arch.badi;
284 	curr_pc = vcpu->arch.pc;
285 	update_pc(&vcpu->arch);
286 
287 	trace_kvm_exit_gspr(vcpu, inst.word);
288 	er = EMULATE_FAIL;
289 	switch (((inst.word >> 24) & 0xff)) {
290 	case 0x0: /* CPUCFG GSPR */
291 		trace_kvm_exit_cpucfg(vcpu, KVM_TRACE_EXIT_CPUCFG);
292 		er = kvm_emu_cpucfg(vcpu, inst);
293 		break;
294 	case 0x4: /* CSR{RD,WR,XCHG} GSPR */
295 		trace_kvm_exit_csr(vcpu, KVM_TRACE_EXIT_CSR);
296 		er = kvm_handle_csr(vcpu, inst);
297 		break;
298 	case 0x6: /* Cache, Idle and IOCSR GSPR */
299 		switch (((inst.word >> 22) & 0x3ff)) {
300 		case 0x18: /* Cache GSPR */
301 			er = EMULATE_DONE;
302 			trace_kvm_exit_cache(vcpu, KVM_TRACE_EXIT_CACHE);
303 			break;
304 		case 0x19: /* Idle/IOCSR GSPR */
305 			switch (((inst.word >> 15) & 0x1ffff)) {
306 			case 0xc90: /* IOCSR GSPR */
307 				er = kvm_emu_iocsr(inst, run, vcpu);
308 				break;
309 			case 0xc91: /* Idle GSPR */
310 				er = kvm_emu_idle(vcpu);
311 				break;
312 			default:
313 				er = EMULATE_FAIL;
314 				break;
315 			}
316 			break;
317 		default:
318 			er = EMULATE_FAIL;
319 			break;
320 		}
321 		break;
322 	default:
323 		er = EMULATE_FAIL;
324 		break;
325 	}
326 
327 	/* Rollback PC only if emulation was unsuccessful */
328 	if (er == EMULATE_FAIL) {
329 		kvm_err("[%#lx]%s: unsupported gspr instruction 0x%08x\n",
330 			curr_pc, __func__, inst.word);
331 
332 		kvm_arch_vcpu_dump_regs(vcpu);
333 		vcpu->arch.pc = curr_pc;
334 	}
335 
336 	return er;
337 }
338 
339 /*
340  * Trigger GSPR:
341  * 1) Execute CPUCFG instruction;
342  * 2) Execute CACOP/IDLE instructions;
343  * 3) Access to unimplemented CSRs/IOCSRs.
344  */
345 static int kvm_handle_gspr(struct kvm_vcpu *vcpu, int ecode)
346 {
347 	int ret = RESUME_GUEST;
348 	enum emulation_result er = EMULATE_DONE;
349 
350 	er = kvm_trap_handle_gspr(vcpu);
351 
352 	if (er == EMULATE_DONE) {
353 		ret = RESUME_GUEST;
354 	} else if (er == EMULATE_DO_MMIO) {
355 		vcpu->run->exit_reason = KVM_EXIT_MMIO;
356 		ret = RESUME_HOST;
357 	} else if (er == EMULATE_DO_IOCSR) {
358 		vcpu->run->exit_reason = KVM_EXIT_LOONGARCH_IOCSR;
359 		ret = RESUME_HOST;
360 	} else {
361 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
362 		ret = RESUME_GUEST;
363 	}
364 
365 	return ret;
366 }
367 
368 int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
369 {
370 	int idx, ret;
371 	unsigned int op8, opcode, rd;
372 	struct kvm_run *run = vcpu->run;
373 
374 	run->mmio.phys_addr = vcpu->arch.badv;
375 	vcpu->mmio_needed = 2;	/* signed */
376 	op8 = (inst.word >> 24) & 0xff;
377 	ret = EMULATE_DO_MMIO;
378 
379 	switch (op8) {
380 	case 0x24 ... 0x27:	/* ldptr.w/d process */
381 		rd = inst.reg2i14_format.rd;
382 		opcode = inst.reg2i14_format.opcode;
383 
384 		switch (opcode) {
385 		case ldptrw_op:
386 			run->mmio.len = 4;
387 			break;
388 		case ldptrd_op:
389 			run->mmio.len = 8;
390 			break;
391 		default:
392 			ret = EMULATE_FAIL;
393 			break;
394 		}
395 		break;
396 	case 0x28 ... 0x2e:	/* ld.b/h/w/d, ld.bu/hu/wu process */
397 		rd = inst.reg2i12_format.rd;
398 		opcode = inst.reg2i12_format.opcode;
399 
400 		switch (opcode) {
401 		case ldb_op:
402 			run->mmio.len = 1;
403 			break;
404 		case ldbu_op:
405 			vcpu->mmio_needed = 1;	/* unsigned */
406 			run->mmio.len = 1;
407 			break;
408 		case ldh_op:
409 			run->mmio.len = 2;
410 			break;
411 		case ldhu_op:
412 			vcpu->mmio_needed = 1;	/* unsigned */
413 			run->mmio.len = 2;
414 			break;
415 		case ldw_op:
416 			run->mmio.len = 4;
417 			break;
418 		case ldwu_op:
419 			vcpu->mmio_needed = 1;	/* unsigned */
420 			run->mmio.len = 4;
421 			break;
422 		case ldd_op:
423 			run->mmio.len = 8;
424 			break;
425 		default:
426 			ret = EMULATE_FAIL;
427 			break;
428 		}
429 		break;
430 	case 0x38:	/* ldx.b/h/w/d, ldx.bu/hu/wu process */
431 		rd = inst.reg3_format.rd;
432 		opcode = inst.reg3_format.opcode;
433 
434 		switch (opcode) {
435 		case ldxb_op:
436 			run->mmio.len = 1;
437 			break;
438 		case ldxbu_op:
439 			run->mmio.len = 1;
440 			vcpu->mmio_needed = 1;	/* unsigned */
441 			break;
442 		case ldxh_op:
443 			run->mmio.len = 2;
444 			break;
445 		case ldxhu_op:
446 			run->mmio.len = 2;
447 			vcpu->mmio_needed = 1;	/* unsigned */
448 			break;
449 		case ldxw_op:
450 			run->mmio.len = 4;
451 			break;
452 		case ldxwu_op:
453 			run->mmio.len = 4;
454 			vcpu->mmio_needed = 1;	/* unsigned */
455 			break;
456 		case ldxd_op:
457 			run->mmio.len = 8;
458 			break;
459 		default:
460 			ret = EMULATE_FAIL;
461 			break;
462 		}
463 		break;
464 	default:
465 		ret = EMULATE_FAIL;
466 	}
467 
468 	if (ret == EMULATE_DO_MMIO) {
469 		trace_kvm_mmio(KVM_TRACE_MMIO_READ, run->mmio.len, run->mmio.phys_addr, NULL);
470 
471 		vcpu->arch.io_gpr = rd; /* Set for kvm_complete_mmio_read() use */
472 
473 		/*
474 		 * If mmio device such as PCH-PIC is emulated in KVM,
475 		 * it need not return to user space to handle the mmio
476 		 * exception.
477 		 */
478 		idx = srcu_read_lock(&vcpu->kvm->srcu);
479 		ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, vcpu->arch.badv,
480 				      run->mmio.len, run->mmio.data);
481 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
482 		if (!ret) {
483 			kvm_complete_mmio_read(vcpu, run);
484 			update_pc(&vcpu->arch);
485 			vcpu->mmio_needed = 0;
486 			return EMULATE_DONE;
487 		}
488 
489 		run->mmio.is_write = 0;
490 		vcpu->mmio_is_write = 0;
491 		return EMULATE_DO_MMIO;
492 	}
493 
494 	kvm_err("Read not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
495 			inst.word, vcpu->arch.pc, vcpu->arch.badv);
496 	kvm_arch_vcpu_dump_regs(vcpu);
497 	vcpu->mmio_needed = 0;
498 
499 	return ret;
500 }
501 
502 int kvm_complete_mmio_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
503 {
504 	enum emulation_result er = EMULATE_DONE;
505 	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
506 
507 	/* Update with new PC */
508 	update_pc(&vcpu->arch);
509 	switch (run->mmio.len) {
510 	case 1:
511 		if (vcpu->mmio_needed == 2)
512 			*gpr = *(s8 *)run->mmio.data;
513 		else
514 			*gpr = *(u8 *)run->mmio.data;
515 		break;
516 	case 2:
517 		if (vcpu->mmio_needed == 2)
518 			*gpr = *(s16 *)run->mmio.data;
519 		else
520 			*gpr = *(u16 *)run->mmio.data;
521 		break;
522 	case 4:
523 		if (vcpu->mmio_needed == 2)
524 			*gpr = *(s32 *)run->mmio.data;
525 		else
526 			*gpr = *(u32 *)run->mmio.data;
527 		break;
528 	case 8:
529 		*gpr = *(s64 *)run->mmio.data;
530 		break;
531 	default:
532 		kvm_err("Bad MMIO length: %d, addr is 0x%lx\n",
533 				run->mmio.len, vcpu->arch.badv);
534 		er = EMULATE_FAIL;
535 		break;
536 	}
537 
538 	trace_kvm_mmio(KVM_TRACE_MMIO_READ, run->mmio.len,
539 			run->mmio.phys_addr, run->mmio.data);
540 
541 	return er;
542 }
543 
544 int kvm_emu_mmio_write(struct kvm_vcpu *vcpu, larch_inst inst)
545 {
546 	int idx, ret;
547 	unsigned int rd, op8, opcode;
548 	unsigned long curr_pc, rd_val = 0;
549 	struct kvm_run *run = vcpu->run;
550 	void *data = run->mmio.data;
551 
552 	/*
553 	 * Update PC and hold onto current PC in case there is
554 	 * an error and we want to rollback the PC
555 	 */
556 	curr_pc = vcpu->arch.pc;
557 	update_pc(&vcpu->arch);
558 
559 	op8 = (inst.word >> 24) & 0xff;
560 	run->mmio.phys_addr = vcpu->arch.badv;
561 	ret = EMULATE_DO_MMIO;
562 	switch (op8) {
563 	case 0x24 ... 0x27:	/* stptr.w/d process */
564 		rd = inst.reg2i14_format.rd;
565 		opcode = inst.reg2i14_format.opcode;
566 
567 		switch (opcode) {
568 		case stptrw_op:
569 			run->mmio.len = 4;
570 			*(unsigned int *)data = vcpu->arch.gprs[rd];
571 			break;
572 		case stptrd_op:
573 			run->mmio.len = 8;
574 			*(unsigned long *)data = vcpu->arch.gprs[rd];
575 			break;
576 		default:
577 			ret = EMULATE_FAIL;
578 			break;
579 		}
580 		break;
581 	case 0x28 ... 0x2e:	/* st.b/h/w/d  process */
582 		rd = inst.reg2i12_format.rd;
583 		opcode = inst.reg2i12_format.opcode;
584 		rd_val = vcpu->arch.gprs[rd];
585 
586 		switch (opcode) {
587 		case stb_op:
588 			run->mmio.len = 1;
589 			*(unsigned char *)data = rd_val;
590 			break;
591 		case sth_op:
592 			run->mmio.len = 2;
593 			*(unsigned short *)data = rd_val;
594 			break;
595 		case stw_op:
596 			run->mmio.len = 4;
597 			*(unsigned int *)data = rd_val;
598 			break;
599 		case std_op:
600 			run->mmio.len = 8;
601 			*(unsigned long *)data = rd_val;
602 			break;
603 		default:
604 			ret = EMULATE_FAIL;
605 			break;
606 		}
607 		break;
608 	case 0x38:	/* stx.b/h/w/d process */
609 		rd = inst.reg3_format.rd;
610 		opcode = inst.reg3_format.opcode;
611 
612 		switch (opcode) {
613 		case stxb_op:
614 			run->mmio.len = 1;
615 			*(unsigned char *)data = vcpu->arch.gprs[rd];
616 			break;
617 		case stxh_op:
618 			run->mmio.len = 2;
619 			*(unsigned short *)data = vcpu->arch.gprs[rd];
620 			break;
621 		case stxw_op:
622 			run->mmio.len = 4;
623 			*(unsigned int *)data = vcpu->arch.gprs[rd];
624 			break;
625 		case stxd_op:
626 			run->mmio.len = 8;
627 			*(unsigned long *)data = vcpu->arch.gprs[rd];
628 			break;
629 		default:
630 			ret = EMULATE_FAIL;
631 			break;
632 		}
633 		break;
634 	default:
635 		ret = EMULATE_FAIL;
636 	}
637 
638 	if (ret == EMULATE_DO_MMIO) {
639 		trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, run->mmio.len, run->mmio.phys_addr, data);
640 
641 		/*
642 		 * If mmio device such as PCH-PIC is emulated in KVM,
643 		 * it need not return to user space to handle the mmio
644 		 * exception.
645 		 */
646 		idx = srcu_read_lock(&vcpu->kvm->srcu);
647 		ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, vcpu->arch.badv, run->mmio.len, data);
648 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
649 		if (!ret)
650 			return EMULATE_DONE;
651 
652 		run->mmio.is_write = 1;
653 		vcpu->mmio_needed = 1;
654 		vcpu->mmio_is_write = 1;
655 		return EMULATE_DO_MMIO;
656 	}
657 
658 	vcpu->arch.pc = curr_pc;
659 	kvm_err("Write not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
660 			inst.word, vcpu->arch.pc, vcpu->arch.badv);
661 	kvm_arch_vcpu_dump_regs(vcpu);
662 	/* Rollback PC if emulation was unsuccessful */
663 
664 	return ret;
665 }
666 
667 static int kvm_handle_rdwr_fault(struct kvm_vcpu *vcpu, bool write, int ecode)
668 {
669 	int ret;
670 	larch_inst inst;
671 	enum emulation_result er = EMULATE_DONE;
672 	struct kvm_run *run = vcpu->run;
673 	unsigned long badv = vcpu->arch.badv;
674 
675 	/* Inject ADE exception if exceed max GPA size */
676 	if (unlikely(badv >= vcpu->kvm->arch.gpa_size)) {
677 		kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEM);
678 		return RESUME_GUEST;
679 	}
680 
681 	ret = kvm_handle_mm_fault(vcpu, badv, write, ecode);
682 	if (ret) {
683 		/* Treat as MMIO */
684 		inst.word = vcpu->arch.badi;
685 		if (write) {
686 			er = kvm_emu_mmio_write(vcpu, inst);
687 		} else {
688 			/* A code fetch fault doesn't count as an MMIO */
689 			if (kvm_is_ifetch_fault(&vcpu->arch)) {
690 				kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEF);
691 				return RESUME_GUEST;
692 			}
693 
694 			er = kvm_emu_mmio_read(vcpu, inst);
695 		}
696 	}
697 
698 	if (er == EMULATE_DONE) {
699 		ret = RESUME_GUEST;
700 	} else if (er == EMULATE_DO_MMIO) {
701 		run->exit_reason = KVM_EXIT_MMIO;
702 		ret = RESUME_HOST;
703 	} else {
704 		kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEM);
705 		ret = RESUME_GUEST;
706 	}
707 
708 	return ret;
709 }
710 
711 static int kvm_handle_read_fault(struct kvm_vcpu *vcpu, int ecode)
712 {
713 	return kvm_handle_rdwr_fault(vcpu, false, ecode);
714 }
715 
716 static int kvm_handle_write_fault(struct kvm_vcpu *vcpu, int ecode)
717 {
718 	return kvm_handle_rdwr_fault(vcpu, true, ecode);
719 }
720 
721 int kvm_complete_user_service(struct kvm_vcpu *vcpu, struct kvm_run *run)
722 {
723 	update_pc(&vcpu->arch);
724 	kvm_write_reg(vcpu, LOONGARCH_GPR_A0, run->hypercall.ret);
725 
726 	return 0;
727 }
728 
729 /**
730  * kvm_handle_fpu_disabled() - Guest used fpu however it is disabled at host
731  * @vcpu:	Virtual CPU context.
732  * @ecode:	Exception code.
733  *
734  * Handle when the guest attempts to use fpu which hasn't been allowed
735  * by the root context.
736  */
737 static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu, int ecode)
738 {
739 	struct kvm_run *run = vcpu->run;
740 
741 	if (!kvm_guest_has_fpu(&vcpu->arch)) {
742 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
743 		return RESUME_GUEST;
744 	}
745 
746 	/*
747 	 * If guest FPU not present, the FPU operation should have been
748 	 * treated as a reserved instruction!
749 	 * If FPU already in use, we shouldn't get this at all.
750 	 */
751 	if (WARN_ON(vcpu->arch.aux_inuse & KVM_LARCH_FPU)) {
752 		kvm_err("%s internal error\n", __func__);
753 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
754 		return RESUME_HOST;
755 	}
756 
757 	kvm_make_request(KVM_REQ_FPU_LOAD, vcpu);
758 
759 	return RESUME_GUEST;
760 }
761 
762 static long kvm_save_notify(struct kvm_vcpu *vcpu)
763 {
764 	unsigned long id, data;
765 
766 	id   = kvm_read_reg(vcpu, LOONGARCH_GPR_A1);
767 	data = kvm_read_reg(vcpu, LOONGARCH_GPR_A2);
768 	switch (id) {
769 	case BIT(KVM_FEATURE_STEAL_TIME):
770 		if (data & ~(KVM_STEAL_PHYS_MASK | KVM_STEAL_PHYS_VALID))
771 			return KVM_HCALL_INVALID_PARAMETER;
772 
773 		vcpu->arch.st.guest_addr = data;
774 		if (!(data & KVM_STEAL_PHYS_VALID))
775 			return 0;
776 
777 		vcpu->arch.st.last_steal = current->sched_info.run_delay;
778 		kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
779 		return 0;
780 	default:
781 		return KVM_HCALL_INVALID_CODE;
782 	}
783 }
784 
785 /*
786  * kvm_handle_lsx_disabled() - Guest used LSX while disabled in root.
787  * @vcpu:      Virtual CPU context.
788  * @ecode:	Exception code.
789  *
790  * Handle when the guest attempts to use LSX when it is disabled in the root
791  * context.
792  */
793 static int kvm_handle_lsx_disabled(struct kvm_vcpu *vcpu, int ecode)
794 {
795 	if (!kvm_guest_has_lsx(&vcpu->arch))
796 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
797 	else
798 		kvm_make_request(KVM_REQ_FPU_LOAD, vcpu);
799 
800 	return RESUME_GUEST;
801 }
802 
803 /*
804  * kvm_handle_lasx_disabled() - Guest used LASX while disabled in root.
805  * @vcpu:	Virtual CPU context.
806  * @ecode:	Exception code.
807  *
808  * Handle when the guest attempts to use LASX when it is disabled in the root
809  * context.
810  */
811 static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu, int ecode)
812 {
813 	if (!kvm_guest_has_lasx(&vcpu->arch))
814 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
815 	else
816 		kvm_make_request(KVM_REQ_FPU_LOAD, vcpu);
817 
818 	return RESUME_GUEST;
819 }
820 
821 static int kvm_handle_lbt_disabled(struct kvm_vcpu *vcpu, int ecode)
822 {
823 	if (!kvm_guest_has_lbt(&vcpu->arch))
824 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
825 	else
826 		kvm_make_request(KVM_REQ_LBT_LOAD, vcpu);
827 
828 	return RESUME_GUEST;
829 }
830 
831 static void kvm_send_pv_ipi(struct kvm_vcpu *vcpu)
832 {
833 	unsigned int min, cpu;
834 	struct kvm_vcpu *dest;
835 	DECLARE_BITMAP(ipi_bitmap, BITS_PER_LONG * 2) = {
836 		kvm_read_reg(vcpu, LOONGARCH_GPR_A1),
837 		kvm_read_reg(vcpu, LOONGARCH_GPR_A2)
838 	};
839 
840 	min = kvm_read_reg(vcpu, LOONGARCH_GPR_A3);
841 	for_each_set_bit(cpu, ipi_bitmap, BITS_PER_LONG * 2) {
842 		dest = kvm_get_vcpu_by_cpuid(vcpu->kvm, cpu + min);
843 		if (!dest)
844 			continue;
845 
846 		/* Send SWI0 to dest vcpu to emulate IPI interrupt */
847 		kvm_queue_irq(dest, INT_SWI0);
848 		kvm_vcpu_kick(dest);
849 	}
850 }
851 
852 /*
853  * Hypercall emulation always return to guest, Caller should check retval.
854  */
855 static void kvm_handle_service(struct kvm_vcpu *vcpu)
856 {
857 	long ret = KVM_HCALL_INVALID_CODE;
858 	unsigned long func = kvm_read_reg(vcpu, LOONGARCH_GPR_A0);
859 
860 	switch (func) {
861 	case KVM_HCALL_FUNC_IPI:
862 		if (kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_IPI)) {
863 			kvm_send_pv_ipi(vcpu);
864 			ret = KVM_HCALL_SUCCESS;
865 		}
866 		break;
867 	case KVM_HCALL_FUNC_NOTIFY:
868 		if (kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_STEAL_TIME))
869 			ret = kvm_save_notify(vcpu);
870 		break;
871 	default:
872 		break;
873 	}
874 
875 	kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret);
876 }
877 
878 static int kvm_handle_hypercall(struct kvm_vcpu *vcpu, int ecode)
879 {
880 	int ret;
881 	larch_inst inst;
882 	unsigned int code;
883 
884 	inst.word = vcpu->arch.badi;
885 	code = inst.reg0i15_format.immediate;
886 	ret = RESUME_GUEST;
887 
888 	switch (code) {
889 	case KVM_HCALL_SERVICE:
890 		vcpu->stat.hypercall_exits++;
891 		kvm_handle_service(vcpu);
892 		break;
893 	case KVM_HCALL_USER_SERVICE:
894 		if (!kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_USER_HCALL)) {
895 			kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE);
896 			break;
897 		}
898 
899 		vcpu->stat.hypercall_exits++;
900 		vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
901 		vcpu->run->hypercall.nr = KVM_HCALL_USER_SERVICE;
902 		vcpu->run->hypercall.args[0] = kvm_read_reg(vcpu, LOONGARCH_GPR_A0);
903 		vcpu->run->hypercall.args[1] = kvm_read_reg(vcpu, LOONGARCH_GPR_A1);
904 		vcpu->run->hypercall.args[2] = kvm_read_reg(vcpu, LOONGARCH_GPR_A2);
905 		vcpu->run->hypercall.args[3] = kvm_read_reg(vcpu, LOONGARCH_GPR_A3);
906 		vcpu->run->hypercall.args[4] = kvm_read_reg(vcpu, LOONGARCH_GPR_A4);
907 		vcpu->run->hypercall.args[5] = kvm_read_reg(vcpu, LOONGARCH_GPR_A5);
908 		vcpu->run->hypercall.flags = 0;
909 		/*
910 		 * Set invalid return value by default, let user-mode VMM modify it.
911 		 */
912 		vcpu->run->hypercall.ret = KVM_HCALL_INVALID_CODE;
913 		ret = RESUME_HOST;
914 		break;
915 	case KVM_HCALL_SWDBG:
916 		/* KVM_HCALL_SWDBG only in effective when SW_BP is enabled */
917 		if (vcpu->guest_debug & KVM_GUESTDBG_SW_BP_MASK) {
918 			vcpu->run->exit_reason = KVM_EXIT_DEBUG;
919 			ret = RESUME_HOST;
920 			break;
921 		}
922 		fallthrough;
923 	default:
924 		/* Treat it as noop intruction, only set return value */
925 		kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE);
926 		break;
927 	}
928 
929 	if (ret == RESUME_GUEST)
930 		update_pc(&vcpu->arch);
931 
932 	return ret;
933 }
934 
935 /*
936  * LoongArch KVM callback handling for unimplemented guest exiting
937  */
938 static int kvm_fault_ni(struct kvm_vcpu *vcpu, int ecode)
939 {
940 	unsigned int inst;
941 	unsigned long badv;
942 
943 	/* Fetch the instruction */
944 	inst = vcpu->arch.badi;
945 	badv = vcpu->arch.badv;
946 	kvm_err("ECode: %d PC=%#lx Inst=0x%08x BadVaddr=%#lx ESTAT=%#lx\n",
947 			ecode, vcpu->arch.pc, inst, badv, read_gcsr_estat());
948 	kvm_arch_vcpu_dump_regs(vcpu);
949 	kvm_queue_exception(vcpu, EXCCODE_INE, 0);
950 
951 	return RESUME_GUEST;
952 }
953 
954 static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = {
955 	[0 ... EXCCODE_INT_START - 1]	= kvm_fault_ni,
956 	[EXCCODE_TLBI]			= kvm_handle_read_fault,
957 	[EXCCODE_TLBL]			= kvm_handle_read_fault,
958 	[EXCCODE_TLBS]			= kvm_handle_write_fault,
959 	[EXCCODE_TLBM]			= kvm_handle_write_fault,
960 	[EXCCODE_FPDIS]			= kvm_handle_fpu_disabled,
961 	[EXCCODE_LSXDIS]		= kvm_handle_lsx_disabled,
962 	[EXCCODE_LASXDIS]		= kvm_handle_lasx_disabled,
963 	[EXCCODE_BTDIS]			= kvm_handle_lbt_disabled,
964 	[EXCCODE_GSPR]			= kvm_handle_gspr,
965 	[EXCCODE_HVC]			= kvm_handle_hypercall,
966 };
967 
968 int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
969 {
970 	return kvm_fault_tables[fault](vcpu, fault);
971 }
972