xref: /linux/arch/loongarch/kvm/exit.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
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 		old = old & csr_mask;
107 	} else
108 		pr_warn_once("Unsupported csrxchg 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
109 
110 	return old;
111 }
112 
113 static int kvm_handle_csr(struct kvm_vcpu *vcpu, larch_inst inst)
114 {
115 	unsigned int rd, rj, csrid;
116 	unsigned long csr_mask, val = 0;
117 
118 	/*
119 	 * CSR value mask imm
120 	 * rj = 0 means csrrd
121 	 * rj = 1 means csrwr
122 	 * rj != 0,1 means csrxchg
123 	 */
124 	rd = inst.reg2csr_format.rd;
125 	rj = inst.reg2csr_format.rj;
126 	csrid = inst.reg2csr_format.csr;
127 
128 	if (csrid >= LOONGARCH_CSR_PERFCTRL0 && csrid <= vcpu->arch.max_pmu_csrid) {
129 		if (kvm_guest_has_pmu(&vcpu->arch)) {
130 			vcpu->arch.pc -= 4;
131 			kvm_make_request(KVM_REQ_PMU, vcpu);
132 			return EMULATE_DONE;
133 		}
134 	}
135 
136 	/* Process CSR ops */
137 	switch (rj) {
138 	case 0: /* process csrrd */
139 		val = kvm_emu_read_csr(vcpu, csrid);
140 		vcpu->arch.gprs[rd] = val;
141 		break;
142 	case 1: /* process csrwr */
143 		val = vcpu->arch.gprs[rd];
144 		val = kvm_emu_write_csr(vcpu, csrid, val);
145 		vcpu->arch.gprs[rd] = val;
146 		break;
147 	default: /* process csrxchg */
148 		val = vcpu->arch.gprs[rd];
149 		csr_mask = vcpu->arch.gprs[rj];
150 		val = kvm_emu_xchg_csr(vcpu, csrid, csr_mask, val);
151 		vcpu->arch.gprs[rd] = val;
152 	}
153 
154 	return EMULATE_DONE;
155 }
156 
157 int kvm_emu_iocsr(larch_inst inst, struct kvm_run *run, struct kvm_vcpu *vcpu)
158 {
159 	int idx, ret;
160 	unsigned long *val;
161 	u32 addr, rd, rj, opcode;
162 
163 	/*
164 	 * Each IOCSR with different opcode
165 	 */
166 	rd = inst.reg2_format.rd;
167 	rj = inst.reg2_format.rj;
168 	opcode = inst.reg2_format.opcode;
169 	addr = vcpu->arch.gprs[rj];
170 	run->iocsr_io.phys_addr = addr;
171 	run->iocsr_io.is_write = 0;
172 	val = &vcpu->arch.gprs[rd];
173 
174 	/* LoongArch is Little endian */
175 	switch (opcode) {
176 	case iocsrrdb_op:
177 		run->iocsr_io.len = 1;
178 		break;
179 	case iocsrrdh_op:
180 		run->iocsr_io.len = 2;
181 		break;
182 	case iocsrrdw_op:
183 		run->iocsr_io.len = 4;
184 		break;
185 	case iocsrrdd_op:
186 		run->iocsr_io.len = 8;
187 		break;
188 	case iocsrwrb_op:
189 		run->iocsr_io.len = 1;
190 		run->iocsr_io.is_write = 1;
191 		break;
192 	case iocsrwrh_op:
193 		run->iocsr_io.len = 2;
194 		run->iocsr_io.is_write = 1;
195 		break;
196 	case iocsrwrw_op:
197 		run->iocsr_io.len = 4;
198 		run->iocsr_io.is_write = 1;
199 		break;
200 	case iocsrwrd_op:
201 		run->iocsr_io.len = 8;
202 		run->iocsr_io.is_write = 1;
203 		break;
204 	default:
205 		return EMULATE_FAIL;
206 	}
207 
208 	if (run->iocsr_io.is_write) {
209 		idx = srcu_read_lock(&vcpu->kvm->srcu);
210 		ret = kvm_io_bus_write(vcpu, KVM_IOCSR_BUS, addr, run->iocsr_io.len, val);
211 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
212 		if (ret == 0)
213 			ret = EMULATE_DONE;
214 		else {
215 			ret = EMULATE_DO_IOCSR;
216 			/* Save data and let user space to write it */
217 			memcpy(run->iocsr_io.data, val, run->iocsr_io.len);
218 		}
219 		trace_kvm_iocsr(KVM_TRACE_IOCSR_WRITE, run->iocsr_io.len, addr, val);
220 	} else {
221 		vcpu->arch.io_gpr = rd; /* Set register id for iocsr read completion */
222 		idx = srcu_read_lock(&vcpu->kvm->srcu);
223 		ret = kvm_io_bus_read(vcpu, KVM_IOCSR_BUS, addr,
224 				      run->iocsr_io.len, run->iocsr_io.data);
225 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
226 		if (ret == 0) {
227 			kvm_complete_iocsr_read(vcpu, run);
228 			ret = EMULATE_DONE;
229 		} else
230 			ret = EMULATE_DO_IOCSR;
231 		trace_kvm_iocsr(KVM_TRACE_IOCSR_READ, run->iocsr_io.len, addr, NULL);
232 	}
233 
234 	return ret;
235 }
236 
237 int kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
238 {
239 	enum emulation_result er = EMULATE_DONE;
240 	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
241 
242 	switch (run->iocsr_io.len) {
243 	case 1:
244 		*gpr = *(s8 *)run->iocsr_io.data;
245 		break;
246 	case 2:
247 		*gpr = *(s16 *)run->iocsr_io.data;
248 		break;
249 	case 4:
250 		*gpr = *(s32 *)run->iocsr_io.data;
251 		break;
252 	case 8:
253 		*gpr = *(s64 *)run->iocsr_io.data;
254 		break;
255 	default:
256 		kvm_err("Bad IOCSR length: %d, addr is 0x%lx\n",
257 				run->iocsr_io.len, vcpu->arch.badv);
258 		er = EMULATE_FAIL;
259 		break;
260 	}
261 
262 	return er;
263 }
264 
265 int kvm_emu_idle(struct kvm_vcpu *vcpu)
266 {
267 	++vcpu->stat.idle_exits;
268 	trace_kvm_exit_idle(vcpu, KVM_TRACE_EXIT_IDLE);
269 
270 	if (!kvm_arch_vcpu_runnable(vcpu))
271 		kvm_vcpu_halt(vcpu);
272 
273 	return EMULATE_DONE;
274 }
275 
276 static int kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)
277 {
278 	unsigned long curr_pc;
279 	larch_inst inst;
280 	enum emulation_result er = EMULATE_DONE;
281 	struct kvm_run *run = vcpu->run;
282 
283 	/* Fetch the instruction */
284 	inst.word = vcpu->arch.badi;
285 	curr_pc = vcpu->arch.pc;
286 	update_pc(&vcpu->arch);
287 
288 	trace_kvm_exit_gspr(vcpu, inst.word);
289 	er = EMULATE_FAIL;
290 	switch (((inst.word >> 24) & 0xff)) {
291 	case 0x0: /* CPUCFG GSPR */
292 		trace_kvm_exit_cpucfg(vcpu, KVM_TRACE_EXIT_CPUCFG);
293 		er = kvm_emu_cpucfg(vcpu, inst);
294 		break;
295 	case 0x4: /* CSR{RD,WR,XCHG} GSPR */
296 		trace_kvm_exit_csr(vcpu, KVM_TRACE_EXIT_CSR);
297 		er = kvm_handle_csr(vcpu, inst);
298 		break;
299 	case 0x6: /* Cache, Idle and IOCSR GSPR */
300 		switch (((inst.word >> 22) & 0x3ff)) {
301 		case 0x18: /* Cache GSPR */
302 			er = EMULATE_DONE;
303 			trace_kvm_exit_cache(vcpu, KVM_TRACE_EXIT_CACHE);
304 			break;
305 		case 0x19: /* Idle/IOCSR GSPR */
306 			switch (((inst.word >> 15) & 0x1ffff)) {
307 			case 0xc90: /* IOCSR GSPR */
308 				er = kvm_emu_iocsr(inst, run, vcpu);
309 				break;
310 			case 0xc91: /* Idle GSPR */
311 				er = kvm_emu_idle(vcpu);
312 				break;
313 			default:
314 				er = EMULATE_FAIL;
315 				break;
316 			}
317 			break;
318 		default:
319 			er = EMULATE_FAIL;
320 			break;
321 		}
322 		break;
323 	default:
324 		er = EMULATE_FAIL;
325 		break;
326 	}
327 
328 	/* Rollback PC only if emulation was unsuccessful */
329 	if (er == EMULATE_FAIL) {
330 		kvm_err("[%#lx]%s: unsupported gspr instruction 0x%08x\n",
331 			curr_pc, __func__, inst.word);
332 
333 		kvm_arch_vcpu_dump_regs(vcpu);
334 		vcpu->arch.pc = curr_pc;
335 	}
336 
337 	return er;
338 }
339 
340 /*
341  * Trigger GSPR:
342  * 1) Execute CPUCFG instruction;
343  * 2) Execute CACOP/IDLE instructions;
344  * 3) Access to unimplemented CSRs/IOCSRs.
345  */
346 static int kvm_handle_gspr(struct kvm_vcpu *vcpu, int ecode)
347 {
348 	int ret = RESUME_GUEST;
349 	enum emulation_result er = EMULATE_DONE;
350 
351 	er = kvm_trap_handle_gspr(vcpu);
352 
353 	if (er == EMULATE_DONE) {
354 		ret = RESUME_GUEST;
355 	} else if (er == EMULATE_DO_MMIO) {
356 		vcpu->run->exit_reason = KVM_EXIT_MMIO;
357 		ret = RESUME_HOST;
358 	} else if (er == EMULATE_DO_IOCSR) {
359 		vcpu->run->exit_reason = KVM_EXIT_LOONGARCH_IOCSR;
360 		ret = RESUME_HOST;
361 	} else {
362 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
363 		ret = RESUME_GUEST;
364 	}
365 
366 	return ret;
367 }
368 
369 int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
370 {
371 	int idx, ret;
372 	unsigned int op8, opcode, rd;
373 	struct kvm_run *run = vcpu->run;
374 
375 	run->mmio.phys_addr = vcpu->arch.badv;
376 	vcpu->mmio_needed = 2;	/* signed */
377 	op8 = (inst.word >> 24) & 0xff;
378 	ret = EMULATE_DO_MMIO;
379 
380 	switch (op8) {
381 	case 0x24 ... 0x27:	/* ldptr.w/d process */
382 		rd = inst.reg2i14_format.rd;
383 		opcode = inst.reg2i14_format.opcode;
384 
385 		switch (opcode) {
386 		case ldptrw_op:
387 			run->mmio.len = 4;
388 			break;
389 		case ldptrd_op:
390 			run->mmio.len = 8;
391 			break;
392 		default:
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_own_fpu(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_own_lsx(vcpu))
796 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
797 
798 	return RESUME_GUEST;
799 }
800 
801 /*
802  * kvm_handle_lasx_disabled() - Guest used LASX while disabled in root.
803  * @vcpu:	Virtual CPU context.
804  * @ecode:	Exception code.
805  *
806  * Handle when the guest attempts to use LASX when it is disabled in the root
807  * context.
808  */
809 static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu, int ecode)
810 {
811 	if (kvm_own_lasx(vcpu))
812 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
813 
814 	return RESUME_GUEST;
815 }
816 
817 static int kvm_handle_lbt_disabled(struct kvm_vcpu *vcpu, int ecode)
818 {
819 	if (kvm_own_lbt(vcpu))
820 		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
821 
822 	return RESUME_GUEST;
823 }
824 
825 static void kvm_send_pv_ipi(struct kvm_vcpu *vcpu)
826 {
827 	unsigned int min, cpu;
828 	struct kvm_vcpu *dest;
829 	DECLARE_BITMAP(ipi_bitmap, BITS_PER_LONG * 2) = {
830 		kvm_read_reg(vcpu, LOONGARCH_GPR_A1),
831 		kvm_read_reg(vcpu, LOONGARCH_GPR_A2)
832 	};
833 
834 	min = kvm_read_reg(vcpu, LOONGARCH_GPR_A3);
835 	for_each_set_bit(cpu, ipi_bitmap, BITS_PER_LONG * 2) {
836 		dest = kvm_get_vcpu_by_cpuid(vcpu->kvm, cpu + min);
837 		if (!dest)
838 			continue;
839 
840 		/* Send SWI0 to dest vcpu to emulate IPI interrupt */
841 		kvm_queue_irq(dest, INT_SWI0);
842 		kvm_vcpu_kick(dest);
843 	}
844 }
845 
846 /*
847  * Hypercall emulation always return to guest, Caller should check retval.
848  */
849 static void kvm_handle_service(struct kvm_vcpu *vcpu)
850 {
851 	long ret = KVM_HCALL_INVALID_CODE;
852 	unsigned long func = kvm_read_reg(vcpu, LOONGARCH_GPR_A0);
853 
854 	switch (func) {
855 	case KVM_HCALL_FUNC_IPI:
856 		if (kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_IPI)) {
857 			kvm_send_pv_ipi(vcpu);
858 			ret = KVM_HCALL_SUCCESS;
859 		}
860 		break;
861 	case KVM_HCALL_FUNC_NOTIFY:
862 		if (kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_STEAL_TIME))
863 			ret = kvm_save_notify(vcpu);
864 		break;
865 	default:
866 		break;
867 	}
868 
869 	kvm_write_reg(vcpu, LOONGARCH_GPR_A0, ret);
870 }
871 
872 static int kvm_handle_hypercall(struct kvm_vcpu *vcpu, int ecode)
873 {
874 	int ret;
875 	larch_inst inst;
876 	unsigned int code;
877 
878 	inst.word = vcpu->arch.badi;
879 	code = inst.reg0i15_format.immediate;
880 	ret = RESUME_GUEST;
881 
882 	switch (code) {
883 	case KVM_HCALL_SERVICE:
884 		vcpu->stat.hypercall_exits++;
885 		kvm_handle_service(vcpu);
886 		break;
887 	case KVM_HCALL_USER_SERVICE:
888 		if (!kvm_guest_has_pv_feature(vcpu, KVM_FEATURE_USER_HCALL)) {
889 			kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE);
890 			break;
891 		}
892 
893 		vcpu->stat.hypercall_exits++;
894 		vcpu->run->exit_reason = KVM_EXIT_HYPERCALL;
895 		vcpu->run->hypercall.nr = KVM_HCALL_USER_SERVICE;
896 		vcpu->run->hypercall.args[0] = kvm_read_reg(vcpu, LOONGARCH_GPR_A0);
897 		vcpu->run->hypercall.args[1] = kvm_read_reg(vcpu, LOONGARCH_GPR_A1);
898 		vcpu->run->hypercall.args[2] = kvm_read_reg(vcpu, LOONGARCH_GPR_A2);
899 		vcpu->run->hypercall.args[3] = kvm_read_reg(vcpu, LOONGARCH_GPR_A3);
900 		vcpu->run->hypercall.args[4] = kvm_read_reg(vcpu, LOONGARCH_GPR_A4);
901 		vcpu->run->hypercall.args[5] = kvm_read_reg(vcpu, LOONGARCH_GPR_A5);
902 		vcpu->run->hypercall.flags = 0;
903 		/*
904 		 * Set invalid return value by default, let user-mode VMM modify it.
905 		 */
906 		vcpu->run->hypercall.ret = KVM_HCALL_INVALID_CODE;
907 		ret = RESUME_HOST;
908 		break;
909 	case KVM_HCALL_SWDBG:
910 		/* KVM_HCALL_SWDBG only in effective when SW_BP is enabled */
911 		if (vcpu->guest_debug & KVM_GUESTDBG_SW_BP_MASK) {
912 			vcpu->run->exit_reason = KVM_EXIT_DEBUG;
913 			ret = RESUME_HOST;
914 			break;
915 		}
916 		fallthrough;
917 	default:
918 		/* Treat it as noop intruction, only set return value */
919 		kvm_write_reg(vcpu, LOONGARCH_GPR_A0, KVM_HCALL_INVALID_CODE);
920 		break;
921 	}
922 
923 	if (ret == RESUME_GUEST)
924 		update_pc(&vcpu->arch);
925 
926 	return ret;
927 }
928 
929 /*
930  * LoongArch KVM callback handling for unimplemented guest exiting
931  */
932 static int kvm_fault_ni(struct kvm_vcpu *vcpu, int ecode)
933 {
934 	unsigned int inst;
935 	unsigned long badv;
936 
937 	/* Fetch the instruction */
938 	inst = vcpu->arch.badi;
939 	badv = vcpu->arch.badv;
940 	kvm_err("ECode: %d PC=%#lx Inst=0x%08x BadVaddr=%#lx ESTAT=%#lx\n",
941 			ecode, vcpu->arch.pc, inst, badv, read_gcsr_estat());
942 	kvm_arch_vcpu_dump_regs(vcpu);
943 	kvm_queue_exception(vcpu, EXCCODE_INE, 0);
944 
945 	return RESUME_GUEST;
946 }
947 
948 static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = {
949 	[0 ... EXCCODE_INT_START - 1]	= kvm_fault_ni,
950 	[EXCCODE_TLBI]			= kvm_handle_read_fault,
951 	[EXCCODE_TLBL]			= kvm_handle_read_fault,
952 	[EXCCODE_TLBS]			= kvm_handle_write_fault,
953 	[EXCCODE_TLBM]			= kvm_handle_write_fault,
954 	[EXCCODE_FPDIS]			= kvm_handle_fpu_disabled,
955 	[EXCCODE_LSXDIS]		= kvm_handle_lsx_disabled,
956 	[EXCCODE_LASXDIS]		= kvm_handle_lasx_disabled,
957 	[EXCCODE_BTDIS]			= kvm_handle_lbt_disabled,
958 	[EXCCODE_GSPR]			= kvm_handle_gspr,
959 	[EXCCODE_HVC]			= kvm_handle_hypercall,
960 };
961 
962 int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
963 {
964 	return kvm_fault_tables[fault](vcpu, fault);
965 }
966