xref: /linux/arch/riscv/kvm/vcpu.c (revision a90e8608eb0ed93d31ac0feb055f77ce59512542)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2019 Western Digital Corporation or its affiliates.
4  *
5  * Authors:
6  *     Anup Patel <anup.patel@wdc.com>
7  */
8 
9 #include <linux/bitops.h>
10 #include <linux/entry-kvm.h>
11 #include <linux/errno.h>
12 #include <linux/err.h>
13 #include <linux/kdebug.h>
14 #include <linux/module.h>
15 #include <linux/percpu.h>
16 #include <linux/uaccess.h>
17 #include <linux/vmalloc.h>
18 #include <linux/sched/signal.h>
19 #include <linux/fs.h>
20 #include <linux/kvm_host.h>
21 #include <asm/csr.h>
22 #include <asm/cacheflush.h>
23 #include <asm/hwcap.h>
24 #include <asm/sbi.h>
25 
26 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
27 	KVM_GENERIC_VCPU_STATS(),
28 	STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
29 	STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
30 	STATS_DESC_COUNTER(VCPU, mmio_exit_user),
31 	STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
32 	STATS_DESC_COUNTER(VCPU, csr_exit_user),
33 	STATS_DESC_COUNTER(VCPU, csr_exit_kernel),
34 	STATS_DESC_COUNTER(VCPU, signal_exits),
35 	STATS_DESC_COUNTER(VCPU, exits)
36 };
37 
38 const struct kvm_stats_header kvm_vcpu_stats_header = {
39 	.name_size = KVM_STATS_NAME_SIZE,
40 	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
41 	.id_offset = sizeof(struct kvm_stats_header),
42 	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
43 	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
44 		       sizeof(kvm_vcpu_stats_desc),
45 };
46 
47 #define KVM_RISCV_BASE_ISA_MASK		GENMASK(25, 0)
48 
49 #define KVM_ISA_EXT_ARR(ext)		[KVM_RISCV_ISA_EXT_##ext] = RISCV_ISA_EXT_##ext
50 
51 /* Mapping between KVM ISA Extension ID & Host ISA extension ID */
52 static const unsigned long kvm_isa_ext_arr[] = {
53 	[KVM_RISCV_ISA_EXT_A] = RISCV_ISA_EXT_a,
54 	[KVM_RISCV_ISA_EXT_C] = RISCV_ISA_EXT_c,
55 	[KVM_RISCV_ISA_EXT_D] = RISCV_ISA_EXT_d,
56 	[KVM_RISCV_ISA_EXT_F] = RISCV_ISA_EXT_f,
57 	[KVM_RISCV_ISA_EXT_H] = RISCV_ISA_EXT_h,
58 	[KVM_RISCV_ISA_EXT_I] = RISCV_ISA_EXT_i,
59 	[KVM_RISCV_ISA_EXT_M] = RISCV_ISA_EXT_m,
60 
61 	KVM_ISA_EXT_ARR(SSAIA),
62 	KVM_ISA_EXT_ARR(SSTC),
63 	KVM_ISA_EXT_ARR(SVINVAL),
64 	KVM_ISA_EXT_ARR(SVPBMT),
65 	KVM_ISA_EXT_ARR(ZBB),
66 	KVM_ISA_EXT_ARR(ZIHINTPAUSE),
67 	KVM_ISA_EXT_ARR(ZICBOM),
68 	KVM_ISA_EXT_ARR(ZICBOZ),
69 };
70 
71 static unsigned long kvm_riscv_vcpu_base2isa_ext(unsigned long base_ext)
72 {
73 	unsigned long i;
74 
75 	for (i = 0; i < KVM_RISCV_ISA_EXT_MAX; i++) {
76 		if (kvm_isa_ext_arr[i] == base_ext)
77 			return i;
78 	}
79 
80 	return KVM_RISCV_ISA_EXT_MAX;
81 }
82 
83 static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext)
84 {
85 	switch (ext) {
86 	case KVM_RISCV_ISA_EXT_H:
87 		return false;
88 	default:
89 		break;
90 	}
91 
92 	return true;
93 }
94 
95 static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
96 {
97 	switch (ext) {
98 	case KVM_RISCV_ISA_EXT_A:
99 	case KVM_RISCV_ISA_EXT_C:
100 	case KVM_RISCV_ISA_EXT_I:
101 	case KVM_RISCV_ISA_EXT_M:
102 	case KVM_RISCV_ISA_EXT_SSAIA:
103 	case KVM_RISCV_ISA_EXT_SSTC:
104 	case KVM_RISCV_ISA_EXT_SVINVAL:
105 	case KVM_RISCV_ISA_EXT_ZIHINTPAUSE:
106 	case KVM_RISCV_ISA_EXT_ZBB:
107 		return false;
108 	default:
109 		break;
110 	}
111 
112 	return true;
113 }
114 
115 static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
116 {
117 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
118 	struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr;
119 	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
120 	struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context;
121 	bool loaded;
122 
123 	/**
124 	 * The preemption should be disabled here because it races with
125 	 * kvm_sched_out/kvm_sched_in(called from preempt notifiers) which
126 	 * also calls vcpu_load/put.
127 	 */
128 	get_cpu();
129 	loaded = (vcpu->cpu != -1);
130 	if (loaded)
131 		kvm_arch_vcpu_put(vcpu);
132 
133 	vcpu->arch.last_exit_cpu = -1;
134 
135 	memcpy(csr, reset_csr, sizeof(*csr));
136 
137 	memcpy(cntx, reset_cntx, sizeof(*cntx));
138 
139 	kvm_riscv_vcpu_fp_reset(vcpu);
140 
141 	kvm_riscv_vcpu_timer_reset(vcpu);
142 
143 	kvm_riscv_vcpu_aia_reset(vcpu);
144 
145 	bitmap_zero(vcpu->arch.irqs_pending, KVM_RISCV_VCPU_NR_IRQS);
146 	bitmap_zero(vcpu->arch.irqs_pending_mask, KVM_RISCV_VCPU_NR_IRQS);
147 
148 	kvm_riscv_vcpu_pmu_reset(vcpu);
149 
150 	vcpu->arch.hfence_head = 0;
151 	vcpu->arch.hfence_tail = 0;
152 	memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue));
153 
154 	/* Reset the guest CSRs for hotplug usecase */
155 	if (loaded)
156 		kvm_arch_vcpu_load(vcpu, smp_processor_id());
157 	put_cpu();
158 }
159 
160 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
161 {
162 	return 0;
163 }
164 
165 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
166 {
167 	int rc;
168 	struct kvm_cpu_context *cntx;
169 	struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr;
170 	unsigned long host_isa, i;
171 
172 	/* Mark this VCPU never ran */
173 	vcpu->arch.ran_atleast_once = false;
174 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
175 	bitmap_zero(vcpu->arch.isa, RISCV_ISA_EXT_MAX);
176 
177 	/* Setup ISA features available to VCPU */
178 	for (i = 0; i < ARRAY_SIZE(kvm_isa_ext_arr); i++) {
179 		host_isa = kvm_isa_ext_arr[i];
180 		if (__riscv_isa_extension_available(NULL, host_isa) &&
181 		    kvm_riscv_vcpu_isa_enable_allowed(i))
182 			set_bit(host_isa, vcpu->arch.isa);
183 	}
184 
185 	/* Setup vendor, arch, and implementation details */
186 	vcpu->arch.mvendorid = sbi_get_mvendorid();
187 	vcpu->arch.marchid = sbi_get_marchid();
188 	vcpu->arch.mimpid = sbi_get_mimpid();
189 
190 	/* Setup VCPU hfence queue */
191 	spin_lock_init(&vcpu->arch.hfence_lock);
192 
193 	/* Setup reset state of shadow SSTATUS and HSTATUS CSRs */
194 	cntx = &vcpu->arch.guest_reset_context;
195 	cntx->sstatus = SR_SPP | SR_SPIE;
196 	cntx->hstatus = 0;
197 	cntx->hstatus |= HSTATUS_VTW;
198 	cntx->hstatus |= HSTATUS_SPVP;
199 	cntx->hstatus |= HSTATUS_SPV;
200 
201 	/* By default, make CY, TM, and IR counters accessible in VU mode */
202 	reset_csr->scounteren = 0x7;
203 
204 	/* Setup VCPU timer */
205 	kvm_riscv_vcpu_timer_init(vcpu);
206 
207 	/* setup performance monitoring */
208 	kvm_riscv_vcpu_pmu_init(vcpu);
209 
210 	/* Setup VCPU AIA */
211 	rc = kvm_riscv_vcpu_aia_init(vcpu);
212 	if (rc)
213 		return rc;
214 
215 	/* Reset VCPU */
216 	kvm_riscv_reset_vcpu(vcpu);
217 
218 	return 0;
219 }
220 
221 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
222 {
223 	/**
224 	 * vcpu with id 0 is the designated boot cpu.
225 	 * Keep all vcpus with non-zero id in power-off state so that
226 	 * they can be brought up using SBI HSM extension.
227 	 */
228 	if (vcpu->vcpu_idx != 0)
229 		kvm_riscv_vcpu_power_off(vcpu);
230 }
231 
232 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
233 {
234 	/* Cleanup VCPU AIA context */
235 	kvm_riscv_vcpu_aia_deinit(vcpu);
236 
237 	/* Cleanup VCPU timer */
238 	kvm_riscv_vcpu_timer_deinit(vcpu);
239 
240 	kvm_riscv_vcpu_pmu_deinit(vcpu);
241 
242 	/* Free unused pages pre-allocated for G-stage page table mappings */
243 	kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
244 }
245 
246 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
247 {
248 	return kvm_riscv_vcpu_timer_pending(vcpu);
249 }
250 
251 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
252 {
253 }
254 
255 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
256 {
257 }
258 
259 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
260 {
261 	return (kvm_riscv_vcpu_has_interrupts(vcpu, -1UL) &&
262 		!vcpu->arch.power_off && !vcpu->arch.pause);
263 }
264 
265 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
266 {
267 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
268 }
269 
270 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
271 {
272 	return (vcpu->arch.guest_context.sstatus & SR_SPP) ? true : false;
273 }
274 
275 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
276 {
277 	return VM_FAULT_SIGBUS;
278 }
279 
280 static int kvm_riscv_vcpu_get_reg_config(struct kvm_vcpu *vcpu,
281 					 const struct kvm_one_reg *reg)
282 {
283 	unsigned long __user *uaddr =
284 			(unsigned long __user *)(unsigned long)reg->addr;
285 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
286 					    KVM_REG_SIZE_MASK |
287 					    KVM_REG_RISCV_CONFIG);
288 	unsigned long reg_val;
289 
290 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
291 		return -EINVAL;
292 
293 	switch (reg_num) {
294 	case KVM_REG_RISCV_CONFIG_REG(isa):
295 		reg_val = vcpu->arch.isa[0] & KVM_RISCV_BASE_ISA_MASK;
296 		break;
297 	case KVM_REG_RISCV_CONFIG_REG(zicbom_block_size):
298 		if (!riscv_isa_extension_available(vcpu->arch.isa, ZICBOM))
299 			return -EINVAL;
300 		reg_val = riscv_cbom_block_size;
301 		break;
302 	case KVM_REG_RISCV_CONFIG_REG(zicboz_block_size):
303 		if (!riscv_isa_extension_available(vcpu->arch.isa, ZICBOZ))
304 			return -EINVAL;
305 		reg_val = riscv_cboz_block_size;
306 		break;
307 	case KVM_REG_RISCV_CONFIG_REG(mvendorid):
308 		reg_val = vcpu->arch.mvendorid;
309 		break;
310 	case KVM_REG_RISCV_CONFIG_REG(marchid):
311 		reg_val = vcpu->arch.marchid;
312 		break;
313 	case KVM_REG_RISCV_CONFIG_REG(mimpid):
314 		reg_val = vcpu->arch.mimpid;
315 		break;
316 	default:
317 		return -EINVAL;
318 	}
319 
320 	if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
321 		return -EFAULT;
322 
323 	return 0;
324 }
325 
326 static int kvm_riscv_vcpu_set_reg_config(struct kvm_vcpu *vcpu,
327 					 const struct kvm_one_reg *reg)
328 {
329 	unsigned long __user *uaddr =
330 			(unsigned long __user *)(unsigned long)reg->addr;
331 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
332 					    KVM_REG_SIZE_MASK |
333 					    KVM_REG_RISCV_CONFIG);
334 	unsigned long i, isa_ext, reg_val;
335 
336 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
337 		return -EINVAL;
338 
339 	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
340 		return -EFAULT;
341 
342 	switch (reg_num) {
343 	case KVM_REG_RISCV_CONFIG_REG(isa):
344 		/*
345 		 * This ONE REG interface is only defined for
346 		 * single letter extensions.
347 		 */
348 		if (fls(reg_val) >= RISCV_ISA_EXT_BASE)
349 			return -EINVAL;
350 
351 		if (!vcpu->arch.ran_atleast_once) {
352 			/* Ignore the enable/disable request for certain extensions */
353 			for (i = 0; i < RISCV_ISA_EXT_BASE; i++) {
354 				isa_ext = kvm_riscv_vcpu_base2isa_ext(i);
355 				if (isa_ext >= KVM_RISCV_ISA_EXT_MAX) {
356 					reg_val &= ~BIT(i);
357 					continue;
358 				}
359 				if (!kvm_riscv_vcpu_isa_enable_allowed(isa_ext))
360 					if (reg_val & BIT(i))
361 						reg_val &= ~BIT(i);
362 				if (!kvm_riscv_vcpu_isa_disable_allowed(isa_ext))
363 					if (!(reg_val & BIT(i)))
364 						reg_val |= BIT(i);
365 			}
366 			reg_val &= riscv_isa_extension_base(NULL);
367 			/* Do not modify anything beyond single letter extensions */
368 			reg_val = (vcpu->arch.isa[0] & ~KVM_RISCV_BASE_ISA_MASK) |
369 				  (reg_val & KVM_RISCV_BASE_ISA_MASK);
370 			vcpu->arch.isa[0] = reg_val;
371 			kvm_riscv_vcpu_fp_reset(vcpu);
372 		} else {
373 			return -EOPNOTSUPP;
374 		}
375 		break;
376 	case KVM_REG_RISCV_CONFIG_REG(zicbom_block_size):
377 		return -EOPNOTSUPP;
378 	case KVM_REG_RISCV_CONFIG_REG(zicboz_block_size):
379 		return -EOPNOTSUPP;
380 	case KVM_REG_RISCV_CONFIG_REG(mvendorid):
381 		if (!vcpu->arch.ran_atleast_once)
382 			vcpu->arch.mvendorid = reg_val;
383 		else
384 			return -EBUSY;
385 		break;
386 	case KVM_REG_RISCV_CONFIG_REG(marchid):
387 		if (!vcpu->arch.ran_atleast_once)
388 			vcpu->arch.marchid = reg_val;
389 		else
390 			return -EBUSY;
391 		break;
392 	case KVM_REG_RISCV_CONFIG_REG(mimpid):
393 		if (!vcpu->arch.ran_atleast_once)
394 			vcpu->arch.mimpid = reg_val;
395 		else
396 			return -EBUSY;
397 		break;
398 	default:
399 		return -EINVAL;
400 	}
401 
402 	return 0;
403 }
404 
405 static int kvm_riscv_vcpu_get_reg_core(struct kvm_vcpu *vcpu,
406 				       const struct kvm_one_reg *reg)
407 {
408 	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
409 	unsigned long __user *uaddr =
410 			(unsigned long __user *)(unsigned long)reg->addr;
411 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
412 					    KVM_REG_SIZE_MASK |
413 					    KVM_REG_RISCV_CORE);
414 	unsigned long reg_val;
415 
416 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
417 		return -EINVAL;
418 	if (reg_num >= sizeof(struct kvm_riscv_core) / sizeof(unsigned long))
419 		return -EINVAL;
420 
421 	if (reg_num == KVM_REG_RISCV_CORE_REG(regs.pc))
422 		reg_val = cntx->sepc;
423 	else if (KVM_REG_RISCV_CORE_REG(regs.pc) < reg_num &&
424 		 reg_num <= KVM_REG_RISCV_CORE_REG(regs.t6))
425 		reg_val = ((unsigned long *)cntx)[reg_num];
426 	else if (reg_num == KVM_REG_RISCV_CORE_REG(mode))
427 		reg_val = (cntx->sstatus & SR_SPP) ?
428 				KVM_RISCV_MODE_S : KVM_RISCV_MODE_U;
429 	else
430 		return -EINVAL;
431 
432 	if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
433 		return -EFAULT;
434 
435 	return 0;
436 }
437 
438 static int kvm_riscv_vcpu_set_reg_core(struct kvm_vcpu *vcpu,
439 				       const struct kvm_one_reg *reg)
440 {
441 	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
442 	unsigned long __user *uaddr =
443 			(unsigned long __user *)(unsigned long)reg->addr;
444 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
445 					    KVM_REG_SIZE_MASK |
446 					    KVM_REG_RISCV_CORE);
447 	unsigned long reg_val;
448 
449 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
450 		return -EINVAL;
451 	if (reg_num >= sizeof(struct kvm_riscv_core) / sizeof(unsigned long))
452 		return -EINVAL;
453 
454 	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
455 		return -EFAULT;
456 
457 	if (reg_num == KVM_REG_RISCV_CORE_REG(regs.pc))
458 		cntx->sepc = reg_val;
459 	else if (KVM_REG_RISCV_CORE_REG(regs.pc) < reg_num &&
460 		 reg_num <= KVM_REG_RISCV_CORE_REG(regs.t6))
461 		((unsigned long *)cntx)[reg_num] = reg_val;
462 	else if (reg_num == KVM_REG_RISCV_CORE_REG(mode)) {
463 		if (reg_val == KVM_RISCV_MODE_S)
464 			cntx->sstatus |= SR_SPP;
465 		else
466 			cntx->sstatus &= ~SR_SPP;
467 	} else
468 		return -EINVAL;
469 
470 	return 0;
471 }
472 
473 static int kvm_riscv_vcpu_general_get_csr(struct kvm_vcpu *vcpu,
474 					  unsigned long reg_num,
475 					  unsigned long *out_val)
476 {
477 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
478 
479 	if (reg_num >= sizeof(struct kvm_riscv_csr) / sizeof(unsigned long))
480 		return -EINVAL;
481 
482 	if (reg_num == KVM_REG_RISCV_CSR_REG(sip)) {
483 		kvm_riscv_vcpu_flush_interrupts(vcpu);
484 		*out_val = (csr->hvip >> VSIP_TO_HVIP_SHIFT) & VSIP_VALID_MASK;
485 		*out_val |= csr->hvip & ~IRQ_LOCAL_MASK;
486 	} else
487 		*out_val = ((unsigned long *)csr)[reg_num];
488 
489 	return 0;
490 }
491 
492 static inline int kvm_riscv_vcpu_general_set_csr(struct kvm_vcpu *vcpu,
493 						 unsigned long reg_num,
494 						 unsigned long reg_val)
495 {
496 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
497 
498 	if (reg_num >= sizeof(struct kvm_riscv_csr) / sizeof(unsigned long))
499 		return -EINVAL;
500 
501 	if (reg_num == KVM_REG_RISCV_CSR_REG(sip)) {
502 		reg_val &= VSIP_VALID_MASK;
503 		reg_val <<= VSIP_TO_HVIP_SHIFT;
504 	}
505 
506 	((unsigned long *)csr)[reg_num] = reg_val;
507 
508 	if (reg_num == KVM_REG_RISCV_CSR_REG(sip))
509 		WRITE_ONCE(vcpu->arch.irqs_pending_mask[0], 0);
510 
511 	return 0;
512 }
513 
514 static int kvm_riscv_vcpu_get_reg_csr(struct kvm_vcpu *vcpu,
515 				      const struct kvm_one_reg *reg)
516 {
517 	int rc;
518 	unsigned long __user *uaddr =
519 			(unsigned long __user *)(unsigned long)reg->addr;
520 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
521 					    KVM_REG_SIZE_MASK |
522 					    KVM_REG_RISCV_CSR);
523 	unsigned long reg_val, reg_subtype;
524 
525 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
526 		return -EINVAL;
527 
528 	reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
529 	reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
530 	switch (reg_subtype) {
531 	case KVM_REG_RISCV_CSR_GENERAL:
532 		rc = kvm_riscv_vcpu_general_get_csr(vcpu, reg_num, &reg_val);
533 		break;
534 	case KVM_REG_RISCV_CSR_AIA:
535 		rc = kvm_riscv_vcpu_aia_get_csr(vcpu, reg_num, &reg_val);
536 		break;
537 	default:
538 		rc = -EINVAL;
539 		break;
540 	}
541 	if (rc)
542 		return rc;
543 
544 	if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
545 		return -EFAULT;
546 
547 	return 0;
548 }
549 
550 static int kvm_riscv_vcpu_set_reg_csr(struct kvm_vcpu *vcpu,
551 				      const struct kvm_one_reg *reg)
552 {
553 	int rc;
554 	unsigned long __user *uaddr =
555 			(unsigned long __user *)(unsigned long)reg->addr;
556 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
557 					    KVM_REG_SIZE_MASK |
558 					    KVM_REG_RISCV_CSR);
559 	unsigned long reg_val, reg_subtype;
560 
561 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
562 		return -EINVAL;
563 
564 	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
565 		return -EFAULT;
566 
567 	reg_subtype = reg_num & KVM_REG_RISCV_SUBTYPE_MASK;
568 	reg_num &= ~KVM_REG_RISCV_SUBTYPE_MASK;
569 	switch (reg_subtype) {
570 	case KVM_REG_RISCV_CSR_GENERAL:
571 		rc = kvm_riscv_vcpu_general_set_csr(vcpu, reg_num, reg_val);
572 		break;
573 	case KVM_REG_RISCV_CSR_AIA:
574 		rc = kvm_riscv_vcpu_aia_set_csr(vcpu, reg_num, reg_val);
575 		break;
576 	default:
577 		rc = -EINVAL;
578 		break;
579 	}
580 	if (rc)
581 		return rc;
582 
583 	return 0;
584 }
585 
586 static int kvm_riscv_vcpu_get_reg_isa_ext(struct kvm_vcpu *vcpu,
587 					  const struct kvm_one_reg *reg)
588 {
589 	unsigned long __user *uaddr =
590 			(unsigned long __user *)(unsigned long)reg->addr;
591 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
592 					    KVM_REG_SIZE_MASK |
593 					    KVM_REG_RISCV_ISA_EXT);
594 	unsigned long reg_val = 0;
595 	unsigned long host_isa_ext;
596 
597 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
598 		return -EINVAL;
599 
600 	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
601 	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
602 		return -EINVAL;
603 
604 	host_isa_ext = kvm_isa_ext_arr[reg_num];
605 	if (__riscv_isa_extension_available(vcpu->arch.isa, host_isa_ext))
606 		reg_val = 1; /* Mark the given extension as available */
607 
608 	if (copy_to_user(uaddr, &reg_val, KVM_REG_SIZE(reg->id)))
609 		return -EFAULT;
610 
611 	return 0;
612 }
613 
614 static int kvm_riscv_vcpu_set_reg_isa_ext(struct kvm_vcpu *vcpu,
615 					  const struct kvm_one_reg *reg)
616 {
617 	unsigned long __user *uaddr =
618 			(unsigned long __user *)(unsigned long)reg->addr;
619 	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
620 					    KVM_REG_SIZE_MASK |
621 					    KVM_REG_RISCV_ISA_EXT);
622 	unsigned long reg_val;
623 	unsigned long host_isa_ext;
624 
625 	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
626 		return -EINVAL;
627 
628 	if (reg_num >= KVM_RISCV_ISA_EXT_MAX ||
629 	    reg_num >= ARRAY_SIZE(kvm_isa_ext_arr))
630 		return -EINVAL;
631 
632 	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
633 		return -EFAULT;
634 
635 	host_isa_ext = kvm_isa_ext_arr[reg_num];
636 	if (!__riscv_isa_extension_available(NULL, host_isa_ext))
637 		return	-EOPNOTSUPP;
638 
639 	if (!vcpu->arch.ran_atleast_once) {
640 		/*
641 		 * All multi-letter extension and a few single letter
642 		 * extension can be disabled
643 		 */
644 		if (reg_val == 1 &&
645 		    kvm_riscv_vcpu_isa_enable_allowed(reg_num))
646 			set_bit(host_isa_ext, vcpu->arch.isa);
647 		else if (!reg_val &&
648 			 kvm_riscv_vcpu_isa_disable_allowed(reg_num))
649 			clear_bit(host_isa_ext, vcpu->arch.isa);
650 		else
651 			return -EINVAL;
652 		kvm_riscv_vcpu_fp_reset(vcpu);
653 	} else {
654 		return -EOPNOTSUPP;
655 	}
656 
657 	return 0;
658 }
659 
660 static int kvm_riscv_vcpu_set_reg(struct kvm_vcpu *vcpu,
661 				  const struct kvm_one_reg *reg)
662 {
663 	switch (reg->id & KVM_REG_RISCV_TYPE_MASK) {
664 	case KVM_REG_RISCV_CONFIG:
665 		return kvm_riscv_vcpu_set_reg_config(vcpu, reg);
666 	case KVM_REG_RISCV_CORE:
667 		return kvm_riscv_vcpu_set_reg_core(vcpu, reg);
668 	case KVM_REG_RISCV_CSR:
669 		return kvm_riscv_vcpu_set_reg_csr(vcpu, reg);
670 	case KVM_REG_RISCV_TIMER:
671 		return kvm_riscv_vcpu_set_reg_timer(vcpu, reg);
672 	case KVM_REG_RISCV_FP_F:
673 		return kvm_riscv_vcpu_set_reg_fp(vcpu, reg,
674 						 KVM_REG_RISCV_FP_F);
675 	case KVM_REG_RISCV_FP_D:
676 		return kvm_riscv_vcpu_set_reg_fp(vcpu, reg,
677 						 KVM_REG_RISCV_FP_D);
678 	case KVM_REG_RISCV_ISA_EXT:
679 		return kvm_riscv_vcpu_set_reg_isa_ext(vcpu, reg);
680 	case KVM_REG_RISCV_SBI_EXT:
681 		return kvm_riscv_vcpu_set_reg_sbi_ext(vcpu, reg);
682 	default:
683 		break;
684 	}
685 
686 	return -EINVAL;
687 }
688 
689 static int kvm_riscv_vcpu_get_reg(struct kvm_vcpu *vcpu,
690 				  const struct kvm_one_reg *reg)
691 {
692 	switch (reg->id & KVM_REG_RISCV_TYPE_MASK) {
693 	case KVM_REG_RISCV_CONFIG:
694 		return kvm_riscv_vcpu_get_reg_config(vcpu, reg);
695 	case KVM_REG_RISCV_CORE:
696 		return kvm_riscv_vcpu_get_reg_core(vcpu, reg);
697 	case KVM_REG_RISCV_CSR:
698 		return kvm_riscv_vcpu_get_reg_csr(vcpu, reg);
699 	case KVM_REG_RISCV_TIMER:
700 		return kvm_riscv_vcpu_get_reg_timer(vcpu, reg);
701 	case KVM_REG_RISCV_FP_F:
702 		return kvm_riscv_vcpu_get_reg_fp(vcpu, reg,
703 						 KVM_REG_RISCV_FP_F);
704 	case KVM_REG_RISCV_FP_D:
705 		return kvm_riscv_vcpu_get_reg_fp(vcpu, reg,
706 						 KVM_REG_RISCV_FP_D);
707 	case KVM_REG_RISCV_ISA_EXT:
708 		return kvm_riscv_vcpu_get_reg_isa_ext(vcpu, reg);
709 	case KVM_REG_RISCV_SBI_EXT:
710 		return kvm_riscv_vcpu_get_reg_sbi_ext(vcpu, reg);
711 	default:
712 		break;
713 	}
714 
715 	return -EINVAL;
716 }
717 
718 long kvm_arch_vcpu_async_ioctl(struct file *filp,
719 			       unsigned int ioctl, unsigned long arg)
720 {
721 	struct kvm_vcpu *vcpu = filp->private_data;
722 	void __user *argp = (void __user *)arg;
723 
724 	if (ioctl == KVM_INTERRUPT) {
725 		struct kvm_interrupt irq;
726 
727 		if (copy_from_user(&irq, argp, sizeof(irq)))
728 			return -EFAULT;
729 
730 		if (irq.irq == KVM_INTERRUPT_SET)
731 			return kvm_riscv_vcpu_set_interrupt(vcpu, IRQ_VS_EXT);
732 		else
733 			return kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);
734 	}
735 
736 	return -ENOIOCTLCMD;
737 }
738 
739 long kvm_arch_vcpu_ioctl(struct file *filp,
740 			 unsigned int ioctl, unsigned long arg)
741 {
742 	struct kvm_vcpu *vcpu = filp->private_data;
743 	void __user *argp = (void __user *)arg;
744 	long r = -EINVAL;
745 
746 	switch (ioctl) {
747 	case KVM_SET_ONE_REG:
748 	case KVM_GET_ONE_REG: {
749 		struct kvm_one_reg reg;
750 
751 		r = -EFAULT;
752 		if (copy_from_user(&reg, argp, sizeof(reg)))
753 			break;
754 
755 		if (ioctl == KVM_SET_ONE_REG)
756 			r = kvm_riscv_vcpu_set_reg(vcpu, &reg);
757 		else
758 			r = kvm_riscv_vcpu_get_reg(vcpu, &reg);
759 		break;
760 	}
761 	default:
762 		break;
763 	}
764 
765 	return r;
766 }
767 
768 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
769 				  struct kvm_sregs *sregs)
770 {
771 	return -EINVAL;
772 }
773 
774 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
775 				  struct kvm_sregs *sregs)
776 {
777 	return -EINVAL;
778 }
779 
780 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
781 {
782 	return -EINVAL;
783 }
784 
785 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
786 {
787 	return -EINVAL;
788 }
789 
790 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
791 				  struct kvm_translation *tr)
792 {
793 	return -EINVAL;
794 }
795 
796 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
797 {
798 	return -EINVAL;
799 }
800 
801 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
802 {
803 	return -EINVAL;
804 }
805 
806 void kvm_riscv_vcpu_flush_interrupts(struct kvm_vcpu *vcpu)
807 {
808 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
809 	unsigned long mask, val;
810 
811 	if (READ_ONCE(vcpu->arch.irqs_pending_mask[0])) {
812 		mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[0], 0);
813 		val = READ_ONCE(vcpu->arch.irqs_pending[0]) & mask;
814 
815 		csr->hvip &= ~mask;
816 		csr->hvip |= val;
817 	}
818 
819 	/* Flush AIA high interrupts */
820 	kvm_riscv_vcpu_aia_flush_interrupts(vcpu);
821 }
822 
823 void kvm_riscv_vcpu_sync_interrupts(struct kvm_vcpu *vcpu)
824 {
825 	unsigned long hvip;
826 	struct kvm_vcpu_arch *v = &vcpu->arch;
827 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
828 
829 	/* Read current HVIP and VSIE CSRs */
830 	csr->vsie = csr_read(CSR_VSIE);
831 
832 	/* Sync-up HVIP.VSSIP bit changes does by Guest */
833 	hvip = csr_read(CSR_HVIP);
834 	if ((csr->hvip ^ hvip) & (1UL << IRQ_VS_SOFT)) {
835 		if (hvip & (1UL << IRQ_VS_SOFT)) {
836 			if (!test_and_set_bit(IRQ_VS_SOFT,
837 					      v->irqs_pending_mask))
838 				set_bit(IRQ_VS_SOFT, v->irqs_pending);
839 		} else {
840 			if (!test_and_set_bit(IRQ_VS_SOFT,
841 					      v->irqs_pending_mask))
842 				clear_bit(IRQ_VS_SOFT, v->irqs_pending);
843 		}
844 	}
845 
846 	/* Sync-up AIA high interrupts */
847 	kvm_riscv_vcpu_aia_sync_interrupts(vcpu);
848 
849 	/* Sync-up timer CSRs */
850 	kvm_riscv_vcpu_timer_sync(vcpu);
851 }
852 
853 int kvm_riscv_vcpu_set_interrupt(struct kvm_vcpu *vcpu, unsigned int irq)
854 {
855 	/*
856 	 * We only allow VS-mode software, timer, and external
857 	 * interrupts when irq is one of the local interrupts
858 	 * defined by RISC-V privilege specification.
859 	 */
860 	if (irq < IRQ_LOCAL_MAX &&
861 	    irq != IRQ_VS_SOFT &&
862 	    irq != IRQ_VS_TIMER &&
863 	    irq != IRQ_VS_EXT)
864 		return -EINVAL;
865 
866 	set_bit(irq, vcpu->arch.irqs_pending);
867 	smp_mb__before_atomic();
868 	set_bit(irq, vcpu->arch.irqs_pending_mask);
869 
870 	kvm_vcpu_kick(vcpu);
871 
872 	return 0;
873 }
874 
875 int kvm_riscv_vcpu_unset_interrupt(struct kvm_vcpu *vcpu, unsigned int irq)
876 {
877 	/*
878 	 * We only allow VS-mode software, timer, and external
879 	 * interrupts when irq is one of the local interrupts
880 	 * defined by RISC-V privilege specification.
881 	 */
882 	if (irq < IRQ_LOCAL_MAX &&
883 	    irq != IRQ_VS_SOFT &&
884 	    irq != IRQ_VS_TIMER &&
885 	    irq != IRQ_VS_EXT)
886 		return -EINVAL;
887 
888 	clear_bit(irq, vcpu->arch.irqs_pending);
889 	smp_mb__before_atomic();
890 	set_bit(irq, vcpu->arch.irqs_pending_mask);
891 
892 	return 0;
893 }
894 
895 bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask)
896 {
897 	unsigned long ie;
898 
899 	ie = ((vcpu->arch.guest_csr.vsie & VSIP_VALID_MASK)
900 		<< VSIP_TO_HVIP_SHIFT) & (unsigned long)mask;
901 	ie |= vcpu->arch.guest_csr.vsie & ~IRQ_LOCAL_MASK &
902 		(unsigned long)mask;
903 	if (READ_ONCE(vcpu->arch.irqs_pending[0]) & ie)
904 		return true;
905 
906 	/* Check AIA high interrupts */
907 	return kvm_riscv_vcpu_aia_has_interrupts(vcpu, mask);
908 }
909 
910 void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu)
911 {
912 	vcpu->arch.power_off = true;
913 	kvm_make_request(KVM_REQ_SLEEP, vcpu);
914 	kvm_vcpu_kick(vcpu);
915 }
916 
917 void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu)
918 {
919 	vcpu->arch.power_off = false;
920 	kvm_vcpu_wake_up(vcpu);
921 }
922 
923 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
924 				    struct kvm_mp_state *mp_state)
925 {
926 	if (vcpu->arch.power_off)
927 		mp_state->mp_state = KVM_MP_STATE_STOPPED;
928 	else
929 		mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
930 
931 	return 0;
932 }
933 
934 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
935 				    struct kvm_mp_state *mp_state)
936 {
937 	int ret = 0;
938 
939 	switch (mp_state->mp_state) {
940 	case KVM_MP_STATE_RUNNABLE:
941 		vcpu->arch.power_off = false;
942 		break;
943 	case KVM_MP_STATE_STOPPED:
944 		kvm_riscv_vcpu_power_off(vcpu);
945 		break;
946 	default:
947 		ret = -EINVAL;
948 	}
949 
950 	return ret;
951 }
952 
953 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
954 					struct kvm_guest_debug *dbg)
955 {
956 	/* TODO; To be implemented later. */
957 	return -EINVAL;
958 }
959 
960 static void kvm_riscv_vcpu_update_config(const unsigned long *isa)
961 {
962 	u64 henvcfg = 0;
963 
964 	if (riscv_isa_extension_available(isa, SVPBMT))
965 		henvcfg |= ENVCFG_PBMTE;
966 
967 	if (riscv_isa_extension_available(isa, SSTC))
968 		henvcfg |= ENVCFG_STCE;
969 
970 	if (riscv_isa_extension_available(isa, ZICBOM))
971 		henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE);
972 
973 	if (riscv_isa_extension_available(isa, ZICBOZ))
974 		henvcfg |= ENVCFG_CBZE;
975 
976 	csr_write(CSR_HENVCFG, henvcfg);
977 #ifdef CONFIG_32BIT
978 	csr_write(CSR_HENVCFGH, henvcfg >> 32);
979 #endif
980 }
981 
982 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
983 {
984 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
985 
986 	csr_write(CSR_VSSTATUS, csr->vsstatus);
987 	csr_write(CSR_VSIE, csr->vsie);
988 	csr_write(CSR_VSTVEC, csr->vstvec);
989 	csr_write(CSR_VSSCRATCH, csr->vsscratch);
990 	csr_write(CSR_VSEPC, csr->vsepc);
991 	csr_write(CSR_VSCAUSE, csr->vscause);
992 	csr_write(CSR_VSTVAL, csr->vstval);
993 	csr_write(CSR_HVIP, csr->hvip);
994 	csr_write(CSR_VSATP, csr->vsatp);
995 
996 	kvm_riscv_vcpu_update_config(vcpu->arch.isa);
997 
998 	kvm_riscv_gstage_update_hgatp(vcpu);
999 
1000 	kvm_riscv_vcpu_timer_restore(vcpu);
1001 
1002 	kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context);
1003 	kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context,
1004 					vcpu->arch.isa);
1005 
1006 	kvm_riscv_vcpu_aia_load(vcpu, cpu);
1007 
1008 	vcpu->cpu = cpu;
1009 }
1010 
1011 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
1012 {
1013 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
1014 
1015 	vcpu->cpu = -1;
1016 
1017 	kvm_riscv_vcpu_aia_put(vcpu);
1018 
1019 	kvm_riscv_vcpu_guest_fp_save(&vcpu->arch.guest_context,
1020 				     vcpu->arch.isa);
1021 	kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context);
1022 
1023 	kvm_riscv_vcpu_timer_save(vcpu);
1024 
1025 	csr->vsstatus = csr_read(CSR_VSSTATUS);
1026 	csr->vsie = csr_read(CSR_VSIE);
1027 	csr->vstvec = csr_read(CSR_VSTVEC);
1028 	csr->vsscratch = csr_read(CSR_VSSCRATCH);
1029 	csr->vsepc = csr_read(CSR_VSEPC);
1030 	csr->vscause = csr_read(CSR_VSCAUSE);
1031 	csr->vstval = csr_read(CSR_VSTVAL);
1032 	csr->hvip = csr_read(CSR_HVIP);
1033 	csr->vsatp = csr_read(CSR_VSATP);
1034 }
1035 
1036 static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)
1037 {
1038 	struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
1039 
1040 	if (kvm_request_pending(vcpu)) {
1041 		if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) {
1042 			kvm_vcpu_srcu_read_unlock(vcpu);
1043 			rcuwait_wait_event(wait,
1044 				(!vcpu->arch.power_off) && (!vcpu->arch.pause),
1045 				TASK_INTERRUPTIBLE);
1046 			kvm_vcpu_srcu_read_lock(vcpu);
1047 
1048 			if (vcpu->arch.power_off || vcpu->arch.pause) {
1049 				/*
1050 				 * Awaken to handle a signal, request to
1051 				 * sleep again later.
1052 				 */
1053 				kvm_make_request(KVM_REQ_SLEEP, vcpu);
1054 			}
1055 		}
1056 
1057 		if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
1058 			kvm_riscv_reset_vcpu(vcpu);
1059 
1060 		if (kvm_check_request(KVM_REQ_UPDATE_HGATP, vcpu))
1061 			kvm_riscv_gstage_update_hgatp(vcpu);
1062 
1063 		if (kvm_check_request(KVM_REQ_FENCE_I, vcpu))
1064 			kvm_riscv_fence_i_process(vcpu);
1065 
1066 		/*
1067 		 * The generic KVM_REQ_TLB_FLUSH is same as
1068 		 * KVM_REQ_HFENCE_GVMA_VMID_ALL
1069 		 */
1070 		if (kvm_check_request(KVM_REQ_HFENCE_GVMA_VMID_ALL, vcpu))
1071 			kvm_riscv_hfence_gvma_vmid_all_process(vcpu);
1072 
1073 		if (kvm_check_request(KVM_REQ_HFENCE_VVMA_ALL, vcpu))
1074 			kvm_riscv_hfence_vvma_all_process(vcpu);
1075 
1076 		if (kvm_check_request(KVM_REQ_HFENCE, vcpu))
1077 			kvm_riscv_hfence_process(vcpu);
1078 	}
1079 }
1080 
1081 static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu)
1082 {
1083 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
1084 
1085 	csr_write(CSR_HVIP, csr->hvip);
1086 	kvm_riscv_vcpu_aia_update_hvip(vcpu);
1087 }
1088 
1089 /*
1090  * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while
1091  * the vCPU is running.
1092  *
1093  * This must be noinstr as instrumentation may make use of RCU, and this is not
1094  * safe during the EQS.
1095  */
1096 static void noinstr kvm_riscv_vcpu_enter_exit(struct kvm_vcpu *vcpu)
1097 {
1098 	guest_state_enter_irqoff();
1099 	__kvm_riscv_switch_to(&vcpu->arch);
1100 	vcpu->arch.last_exit_cpu = vcpu->cpu;
1101 	guest_state_exit_irqoff();
1102 }
1103 
1104 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
1105 {
1106 	int ret;
1107 	struct kvm_cpu_trap trap;
1108 	struct kvm_run *run = vcpu->run;
1109 
1110 	/* Mark this VCPU ran at least once */
1111 	vcpu->arch.ran_atleast_once = true;
1112 
1113 	kvm_vcpu_srcu_read_lock(vcpu);
1114 
1115 	switch (run->exit_reason) {
1116 	case KVM_EXIT_MMIO:
1117 		/* Process MMIO value returned from user-space */
1118 		ret = kvm_riscv_vcpu_mmio_return(vcpu, vcpu->run);
1119 		break;
1120 	case KVM_EXIT_RISCV_SBI:
1121 		/* Process SBI value returned from user-space */
1122 		ret = kvm_riscv_vcpu_sbi_return(vcpu, vcpu->run);
1123 		break;
1124 	case KVM_EXIT_RISCV_CSR:
1125 		/* Process CSR value returned from user-space */
1126 		ret = kvm_riscv_vcpu_csr_return(vcpu, vcpu->run);
1127 		break;
1128 	default:
1129 		ret = 0;
1130 		break;
1131 	}
1132 	if (ret) {
1133 		kvm_vcpu_srcu_read_unlock(vcpu);
1134 		return ret;
1135 	}
1136 
1137 	if (run->immediate_exit) {
1138 		kvm_vcpu_srcu_read_unlock(vcpu);
1139 		return -EINTR;
1140 	}
1141 
1142 	vcpu_load(vcpu);
1143 
1144 	kvm_sigset_activate(vcpu);
1145 
1146 	ret = 1;
1147 	run->exit_reason = KVM_EXIT_UNKNOWN;
1148 	while (ret > 0) {
1149 		/* Check conditions before entering the guest */
1150 		ret = xfer_to_guest_mode_handle_work(vcpu);
1151 		if (ret)
1152 			continue;
1153 		ret = 1;
1154 
1155 		kvm_riscv_gstage_vmid_update(vcpu);
1156 
1157 		kvm_riscv_check_vcpu_requests(vcpu);
1158 
1159 		preempt_disable();
1160 
1161 		/* Update AIA HW state before entering guest */
1162 		ret = kvm_riscv_vcpu_aia_update(vcpu);
1163 		if (ret <= 0) {
1164 			preempt_enable();
1165 			continue;
1166 		}
1167 
1168 		local_irq_disable();
1169 
1170 		/*
1171 		 * Ensure we set mode to IN_GUEST_MODE after we disable
1172 		 * interrupts and before the final VCPU requests check.
1173 		 * See the comment in kvm_vcpu_exiting_guest_mode() and
1174 		 * Documentation/virt/kvm/vcpu-requests.rst
1175 		 */
1176 		vcpu->mode = IN_GUEST_MODE;
1177 
1178 		kvm_vcpu_srcu_read_unlock(vcpu);
1179 		smp_mb__after_srcu_read_unlock();
1180 
1181 		/*
1182 		 * We might have got VCPU interrupts updated asynchronously
1183 		 * so update it in HW.
1184 		 */
1185 		kvm_riscv_vcpu_flush_interrupts(vcpu);
1186 
1187 		/* Update HVIP CSR for current CPU */
1188 		kvm_riscv_update_hvip(vcpu);
1189 
1190 		if (ret <= 0 ||
1191 		    kvm_riscv_gstage_vmid_ver_changed(&vcpu->kvm->arch.vmid) ||
1192 		    kvm_request_pending(vcpu) ||
1193 		    xfer_to_guest_mode_work_pending()) {
1194 			vcpu->mode = OUTSIDE_GUEST_MODE;
1195 			local_irq_enable();
1196 			preempt_enable();
1197 			kvm_vcpu_srcu_read_lock(vcpu);
1198 			continue;
1199 		}
1200 
1201 		/*
1202 		 * Cleanup stale TLB enteries
1203 		 *
1204 		 * Note: This should be done after G-stage VMID has been
1205 		 * updated using kvm_riscv_gstage_vmid_ver_changed()
1206 		 */
1207 		kvm_riscv_local_tlb_sanitize(vcpu);
1208 
1209 		guest_timing_enter_irqoff();
1210 
1211 		kvm_riscv_vcpu_enter_exit(vcpu);
1212 
1213 		vcpu->mode = OUTSIDE_GUEST_MODE;
1214 		vcpu->stat.exits++;
1215 
1216 		/*
1217 		 * Save SCAUSE, STVAL, HTVAL, and HTINST because we might
1218 		 * get an interrupt between __kvm_riscv_switch_to() and
1219 		 * local_irq_enable() which can potentially change CSRs.
1220 		 */
1221 		trap.sepc = vcpu->arch.guest_context.sepc;
1222 		trap.scause = csr_read(CSR_SCAUSE);
1223 		trap.stval = csr_read(CSR_STVAL);
1224 		trap.htval = csr_read(CSR_HTVAL);
1225 		trap.htinst = csr_read(CSR_HTINST);
1226 
1227 		/* Syncup interrupts state with HW */
1228 		kvm_riscv_vcpu_sync_interrupts(vcpu);
1229 
1230 		/*
1231 		 * We must ensure that any pending interrupts are taken before
1232 		 * we exit guest timing so that timer ticks are accounted as
1233 		 * guest time. Transiently unmask interrupts so that any
1234 		 * pending interrupts are taken.
1235 		 *
1236 		 * There's no barrier which ensures that pending interrupts are
1237 		 * recognised, so we just hope that the CPU takes any pending
1238 		 * interrupts between the enable and disable.
1239 		 */
1240 		local_irq_enable();
1241 		local_irq_disable();
1242 
1243 		guest_timing_exit_irqoff();
1244 
1245 		local_irq_enable();
1246 
1247 		preempt_enable();
1248 
1249 		kvm_vcpu_srcu_read_lock(vcpu);
1250 
1251 		ret = kvm_riscv_vcpu_exit(vcpu, run, &trap);
1252 	}
1253 
1254 	kvm_sigset_deactivate(vcpu);
1255 
1256 	vcpu_put(vcpu);
1257 
1258 	kvm_vcpu_srcu_read_unlock(vcpu);
1259 
1260 	return ret;
1261 }
1262