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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: MIPS specific KVM APIs
7  *
8  * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
9  * Authors: Sanjay Lal <sanjayl@kymasys.com>
10  */
11 
12 #include <linux/bitops.h>
13 #include <linux/errno.h>
14 #include <linux/err.h>
15 #include <linux/kdebug.h>
16 #include <linux/module.h>
17 #include <linux/uaccess.h>
18 #include <linux/vmalloc.h>
19 #include <linux/sched/signal.h>
20 #include <linux/fs.h>
21 #include <linux/memblock.h>
22 
23 #include <asm/fpu.h>
24 #include <asm/page.h>
25 #include <asm/cacheflush.h>
26 #include <asm/mmu_context.h>
27 #include <asm/pgalloc.h>
28 #include <asm/pgtable.h>
29 
30 #include <linux/kvm_host.h>
31 
32 #include "interrupt.h"
33 #include "commpage.h"
34 
35 #define CREATE_TRACE_POINTS
36 #include "trace.h"
37 
38 #ifndef VECTORSPACING
39 #define VECTORSPACING 0x100	/* for EI/VI mode */
40 #endif
41 
42 #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x)
43 struct kvm_stats_debugfs_item debugfs_entries[] = {
44 	{ "wait",	  VCPU_STAT(wait_exits),	 KVM_STAT_VCPU },
45 	{ "cache",	  VCPU_STAT(cache_exits),	 KVM_STAT_VCPU },
46 	{ "signal",	  VCPU_STAT(signal_exits),	 KVM_STAT_VCPU },
47 	{ "interrupt",	  VCPU_STAT(int_exits),		 KVM_STAT_VCPU },
48 	{ "cop_unusable", VCPU_STAT(cop_unusable_exits), KVM_STAT_VCPU },
49 	{ "tlbmod",	  VCPU_STAT(tlbmod_exits),	 KVM_STAT_VCPU },
50 	{ "tlbmiss_ld",	  VCPU_STAT(tlbmiss_ld_exits),	 KVM_STAT_VCPU },
51 	{ "tlbmiss_st",	  VCPU_STAT(tlbmiss_st_exits),	 KVM_STAT_VCPU },
52 	{ "addrerr_st",	  VCPU_STAT(addrerr_st_exits),	 KVM_STAT_VCPU },
53 	{ "addrerr_ld",	  VCPU_STAT(addrerr_ld_exits),	 KVM_STAT_VCPU },
54 	{ "syscall",	  VCPU_STAT(syscall_exits),	 KVM_STAT_VCPU },
55 	{ "resvd_inst",	  VCPU_STAT(resvd_inst_exits),	 KVM_STAT_VCPU },
56 	{ "break_inst",	  VCPU_STAT(break_inst_exits),	 KVM_STAT_VCPU },
57 	{ "trap_inst",	  VCPU_STAT(trap_inst_exits),	 KVM_STAT_VCPU },
58 	{ "msa_fpe",	  VCPU_STAT(msa_fpe_exits),	 KVM_STAT_VCPU },
59 	{ "fpe",	  VCPU_STAT(fpe_exits),		 KVM_STAT_VCPU },
60 	{ "msa_disabled", VCPU_STAT(msa_disabled_exits), KVM_STAT_VCPU },
61 	{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
62 #ifdef CONFIG_KVM_MIPS_VZ
63 	{ "vz_gpsi",	  VCPU_STAT(vz_gpsi_exits),	 KVM_STAT_VCPU },
64 	{ "vz_gsfc",	  VCPU_STAT(vz_gsfc_exits),	 KVM_STAT_VCPU },
65 	{ "vz_hc",	  VCPU_STAT(vz_hc_exits),	 KVM_STAT_VCPU },
66 	{ "vz_grr",	  VCPU_STAT(vz_grr_exits),	 KVM_STAT_VCPU },
67 	{ "vz_gva",	  VCPU_STAT(vz_gva_exits),	 KVM_STAT_VCPU },
68 	{ "vz_ghfc",	  VCPU_STAT(vz_ghfc_exits),	 KVM_STAT_VCPU },
69 	{ "vz_gpa",	  VCPU_STAT(vz_gpa_exits),	 KVM_STAT_VCPU },
70 	{ "vz_resvd",	  VCPU_STAT(vz_resvd_exits),	 KVM_STAT_VCPU },
71 #endif
72 	{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
73 	{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), KVM_STAT_VCPU },
74 	{ "halt_poll_invalid", VCPU_STAT(halt_poll_invalid), KVM_STAT_VCPU },
75 	{ "halt_wakeup",  VCPU_STAT(halt_wakeup),	 KVM_STAT_VCPU },
76 	{NULL}
77 };
78 
79 bool kvm_trace_guest_mode_change;
80 
kvm_guest_mode_change_trace_reg(void)81 int kvm_guest_mode_change_trace_reg(void)
82 {
83 	kvm_trace_guest_mode_change = 1;
84 	return 0;
85 }
86 
kvm_guest_mode_change_trace_unreg(void)87 void kvm_guest_mode_change_trace_unreg(void)
88 {
89 	kvm_trace_guest_mode_change = 0;
90 }
91 
92 /*
93  * XXXKYMA: We are simulatoring a processor that has the WII bit set in
94  * Config7, so we are "runnable" if interrupts are pending
95  */
kvm_arch_vcpu_runnable(struct kvm_vcpu * vcpu)96 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
97 {
98 	return !!(vcpu->arch.pending_exceptions);
99 }
100 
kvm_arch_vcpu_in_kernel(struct kvm_vcpu * vcpu)101 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
102 {
103 	return false;
104 }
105 
kvm_arch_vcpu_should_kick(struct kvm_vcpu * vcpu)106 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
107 {
108 	return 1;
109 }
110 
kvm_arch_hardware_enable(void)111 int kvm_arch_hardware_enable(void)
112 {
113 	return kvm_mips_callbacks->hardware_enable();
114 }
115 
kvm_arch_hardware_disable(void)116 void kvm_arch_hardware_disable(void)
117 {
118 	kvm_mips_callbacks->hardware_disable();
119 }
120 
kvm_arch_hardware_setup(void)121 int kvm_arch_hardware_setup(void)
122 {
123 	return 0;
124 }
125 
kvm_arch_check_processor_compat(void)126 int kvm_arch_check_processor_compat(void)
127 {
128 	return 0;
129 }
130 
kvm_arch_init_vm(struct kvm * kvm,unsigned long type)131 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
132 {
133 	switch (type) {
134 	case KVM_VM_MIPS_AUTO:
135 		break;
136 #ifdef CONFIG_KVM_MIPS_VZ
137 	case KVM_VM_MIPS_VZ:
138 #else
139 	case KVM_VM_MIPS_TE:
140 #endif
141 		break;
142 	default:
143 		/* Unsupported KVM type */
144 		return -EINVAL;
145 	};
146 
147 	/* Allocate page table to map GPA -> RPA */
148 	kvm->arch.gpa_mm.pgd = kvm_pgd_alloc();
149 	if (!kvm->arch.gpa_mm.pgd)
150 		return -ENOMEM;
151 
152 	return 0;
153 }
154 
kvm_mips_free_vcpus(struct kvm * kvm)155 void kvm_mips_free_vcpus(struct kvm *kvm)
156 {
157 	unsigned int i;
158 	struct kvm_vcpu *vcpu;
159 
160 	kvm_for_each_vcpu(i, vcpu, kvm) {
161 		kvm_arch_vcpu_free(vcpu);
162 	}
163 
164 	mutex_lock(&kvm->lock);
165 
166 	for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
167 		kvm->vcpus[i] = NULL;
168 
169 	atomic_set(&kvm->online_vcpus, 0);
170 
171 	mutex_unlock(&kvm->lock);
172 }
173 
kvm_mips_free_gpa_pt(struct kvm * kvm)174 static void kvm_mips_free_gpa_pt(struct kvm *kvm)
175 {
176 	/* It should always be safe to remove after flushing the whole range */
177 	WARN_ON(!kvm_mips_flush_gpa_pt(kvm, 0, ~0));
178 	pgd_free(NULL, kvm->arch.gpa_mm.pgd);
179 }
180 
kvm_arch_destroy_vm(struct kvm * kvm)181 void kvm_arch_destroy_vm(struct kvm *kvm)
182 {
183 	kvm_mips_free_vcpus(kvm);
184 	kvm_mips_free_gpa_pt(kvm);
185 }
186 
kvm_arch_dev_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)187 long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
188 			unsigned long arg)
189 {
190 	return -ENOIOCTLCMD;
191 }
192 
kvm_arch_create_memslot(struct kvm * kvm,struct kvm_memory_slot * slot,unsigned long npages)193 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
194 			    unsigned long npages)
195 {
196 	return 0;
197 }
198 
kvm_arch_flush_shadow_all(struct kvm * kvm)199 void kvm_arch_flush_shadow_all(struct kvm *kvm)
200 {
201 	/* Flush whole GPA */
202 	kvm_mips_flush_gpa_pt(kvm, 0, ~0);
203 
204 	/* Let implementation do the rest */
205 	kvm_mips_callbacks->flush_shadow_all(kvm);
206 }
207 
kvm_arch_flush_shadow_memslot(struct kvm * kvm,struct kvm_memory_slot * slot)208 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
209 				   struct kvm_memory_slot *slot)
210 {
211 	/*
212 	 * The slot has been made invalid (ready for moving or deletion), so we
213 	 * need to ensure that it can no longer be accessed by any guest VCPUs.
214 	 */
215 
216 	spin_lock(&kvm->mmu_lock);
217 	/* Flush slot from GPA */
218 	kvm_mips_flush_gpa_pt(kvm, slot->base_gfn,
219 			      slot->base_gfn + slot->npages - 1);
220 	/* Let implementation do the rest */
221 	kvm_mips_callbacks->flush_shadow_memslot(kvm, slot);
222 	spin_unlock(&kvm->mmu_lock);
223 }
224 
kvm_arch_prepare_memory_region(struct kvm * kvm,struct kvm_memory_slot * memslot,const struct kvm_userspace_memory_region * mem,enum kvm_mr_change change)225 int kvm_arch_prepare_memory_region(struct kvm *kvm,
226 				   struct kvm_memory_slot *memslot,
227 				   const struct kvm_userspace_memory_region *mem,
228 				   enum kvm_mr_change change)
229 {
230 	return 0;
231 }
232 
kvm_arch_commit_memory_region(struct kvm * kvm,const struct kvm_userspace_memory_region * mem,const struct kvm_memory_slot * old,const struct kvm_memory_slot * new,enum kvm_mr_change change)233 void kvm_arch_commit_memory_region(struct kvm *kvm,
234 				   const struct kvm_userspace_memory_region *mem,
235 				   const struct kvm_memory_slot *old,
236 				   const struct kvm_memory_slot *new,
237 				   enum kvm_mr_change change)
238 {
239 	int needs_flush;
240 
241 	kvm_debug("%s: kvm: %p slot: %d, GPA: %llx, size: %llx, QVA: %llx\n",
242 		  __func__, kvm, mem->slot, mem->guest_phys_addr,
243 		  mem->memory_size, mem->userspace_addr);
244 
245 	/*
246 	 * If dirty page logging is enabled, write protect all pages in the slot
247 	 * ready for dirty logging.
248 	 *
249 	 * There is no need to do this in any of the following cases:
250 	 * CREATE:	No dirty mappings will already exist.
251 	 * MOVE/DELETE:	The old mappings will already have been cleaned up by
252 	 *		kvm_arch_flush_shadow_memslot()
253 	 */
254 	if (change == KVM_MR_FLAGS_ONLY &&
255 	    (!(old->flags & KVM_MEM_LOG_DIRTY_PAGES) &&
256 	     new->flags & KVM_MEM_LOG_DIRTY_PAGES)) {
257 		spin_lock(&kvm->mmu_lock);
258 		/* Write protect GPA page table entries */
259 		needs_flush = kvm_mips_mkclean_gpa_pt(kvm, new->base_gfn,
260 					new->base_gfn + new->npages - 1);
261 		/* Let implementation do the rest */
262 		if (needs_flush)
263 			kvm_mips_callbacks->flush_shadow_memslot(kvm, new);
264 		spin_unlock(&kvm->mmu_lock);
265 	}
266 }
267 
dump_handler(const char * symbol,void * start,void * end)268 static inline void dump_handler(const char *symbol, void *start, void *end)
269 {
270 	u32 *p;
271 
272 	pr_debug("LEAF(%s)\n", symbol);
273 
274 	pr_debug("\t.set push\n");
275 	pr_debug("\t.set noreorder\n");
276 
277 	for (p = start; p < (u32 *)end; ++p)
278 		pr_debug("\t.word\t0x%08x\t\t# %p\n", *p, p);
279 
280 	pr_debug("\t.set\tpop\n");
281 
282 	pr_debug("\tEND(%s)\n", symbol);
283 }
284 
kvm_arch_vcpu_create(struct kvm * kvm,unsigned int id)285 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
286 {
287 	int err, size;
288 	void *gebase, *p, *handler, *refill_start, *refill_end;
289 	int i;
290 
291 	struct kvm_vcpu *vcpu = kzalloc(sizeof(struct kvm_vcpu), GFP_KERNEL);
292 
293 	if (!vcpu) {
294 		err = -ENOMEM;
295 		goto out;
296 	}
297 
298 	err = kvm_vcpu_init(vcpu, kvm, id);
299 
300 	if (err)
301 		goto out_free_cpu;
302 
303 	kvm_debug("kvm @ %p: create cpu %d at %p\n", kvm, id, vcpu);
304 
305 	/*
306 	 * Allocate space for host mode exception handlers that handle
307 	 * guest mode exits
308 	 */
309 	if (cpu_has_veic || cpu_has_vint)
310 		size = 0x200 + VECTORSPACING * 64;
311 	else
312 		size = 0x4000;
313 
314 	gebase = kzalloc(ALIGN(size, PAGE_SIZE), GFP_KERNEL);
315 
316 	if (!gebase) {
317 		err = -ENOMEM;
318 		goto out_uninit_cpu;
319 	}
320 	kvm_debug("Allocated %d bytes for KVM Exception Handlers @ %p\n",
321 		  ALIGN(size, PAGE_SIZE), gebase);
322 
323 	/*
324 	 * Check new ebase actually fits in CP0_EBase. The lack of a write gate
325 	 * limits us to the low 512MB of physical address space. If the memory
326 	 * we allocate is out of range, just give up now.
327 	 */
328 	if (!cpu_has_ebase_wg && virt_to_phys(gebase) >= 0x20000000) {
329 		kvm_err("CP0_EBase.WG required for guest exception base %pK\n",
330 			gebase);
331 		err = -ENOMEM;
332 		goto out_free_gebase;
333 	}
334 
335 	/* Save new ebase */
336 	vcpu->arch.guest_ebase = gebase;
337 
338 	/* Build guest exception vectors dynamically in unmapped memory */
339 	handler = gebase + 0x2000;
340 
341 	/* TLB refill (or XTLB refill on 64-bit VZ where KX=1) */
342 	refill_start = gebase;
343 	if (IS_ENABLED(CONFIG_KVM_MIPS_VZ) && IS_ENABLED(CONFIG_64BIT))
344 		refill_start += 0x080;
345 	refill_end = kvm_mips_build_tlb_refill_exception(refill_start, handler);
346 
347 	/* General Exception Entry point */
348 	kvm_mips_build_exception(gebase + 0x180, handler);
349 
350 	/* For vectored interrupts poke the exception code @ all offsets 0-7 */
351 	for (i = 0; i < 8; i++) {
352 		kvm_debug("L1 Vectored handler @ %p\n",
353 			  gebase + 0x200 + (i * VECTORSPACING));
354 		kvm_mips_build_exception(gebase + 0x200 + i * VECTORSPACING,
355 					 handler);
356 	}
357 
358 	/* General exit handler */
359 	p = handler;
360 	p = kvm_mips_build_exit(p);
361 
362 	/* Guest entry routine */
363 	vcpu->arch.vcpu_run = p;
364 	p = kvm_mips_build_vcpu_run(p);
365 
366 	/* Dump the generated code */
367 	pr_debug("#include <asm/asm.h>\n");
368 	pr_debug("#include <asm/regdef.h>\n");
369 	pr_debug("\n");
370 	dump_handler("kvm_vcpu_run", vcpu->arch.vcpu_run, p);
371 	dump_handler("kvm_tlb_refill", refill_start, refill_end);
372 	dump_handler("kvm_gen_exc", gebase + 0x180, gebase + 0x200);
373 	dump_handler("kvm_exit", gebase + 0x2000, vcpu->arch.vcpu_run);
374 
375 	/* Invalidate the icache for these ranges */
376 	flush_icache_range((unsigned long)gebase,
377 			   (unsigned long)gebase + ALIGN(size, PAGE_SIZE));
378 
379 	/*
380 	 * Allocate comm page for guest kernel, a TLB will be reserved for
381 	 * mapping GVA @ 0xFFFF8000 to this page
382 	 */
383 	vcpu->arch.kseg0_commpage = kzalloc(PAGE_SIZE << 1, GFP_KERNEL);
384 
385 	if (!vcpu->arch.kseg0_commpage) {
386 		err = -ENOMEM;
387 		goto out_free_gebase;
388 	}
389 
390 	kvm_debug("Allocated COMM page @ %p\n", vcpu->arch.kseg0_commpage);
391 	kvm_mips_commpage_init(vcpu);
392 
393 	/* Init */
394 	vcpu->arch.last_sched_cpu = -1;
395 	vcpu->arch.last_exec_cpu = -1;
396 
397 	return vcpu;
398 
399 out_free_gebase:
400 	kfree(gebase);
401 
402 out_uninit_cpu:
403 	kvm_vcpu_uninit(vcpu);
404 
405 out_free_cpu:
406 	kfree(vcpu);
407 
408 out:
409 	return ERR_PTR(err);
410 }
411 
kvm_arch_vcpu_free(struct kvm_vcpu * vcpu)412 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
413 {
414 	hrtimer_cancel(&vcpu->arch.comparecount_timer);
415 
416 	kvm_vcpu_uninit(vcpu);
417 
418 	kvm_mips_dump_stats(vcpu);
419 
420 	kvm_mmu_free_memory_caches(vcpu);
421 	kfree(vcpu->arch.guest_ebase);
422 	kfree(vcpu->arch.kseg0_commpage);
423 	kfree(vcpu);
424 }
425 
kvm_arch_vcpu_destroy(struct kvm_vcpu * vcpu)426 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
427 {
428 	kvm_arch_vcpu_free(vcpu);
429 }
430 
kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu * vcpu,struct kvm_guest_debug * dbg)431 int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
432 					struct kvm_guest_debug *dbg)
433 {
434 	return -ENOIOCTLCMD;
435 }
436 
kvm_arch_vcpu_ioctl_run(struct kvm_vcpu * vcpu,struct kvm_run * run)437 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
438 {
439 	int r = -EINTR;
440 
441 	vcpu_load(vcpu);
442 
443 	kvm_sigset_activate(vcpu);
444 
445 	if (vcpu->mmio_needed) {
446 		if (!vcpu->mmio_is_write)
447 			kvm_mips_complete_mmio_load(vcpu, run);
448 		vcpu->mmio_needed = 0;
449 	}
450 
451 	if (run->immediate_exit)
452 		goto out;
453 
454 	lose_fpu(1);
455 
456 	local_irq_disable();
457 	guest_enter_irqoff();
458 	trace_kvm_enter(vcpu);
459 
460 	/*
461 	 * Make sure the read of VCPU requests in vcpu_run() callback is not
462 	 * reordered ahead of the write to vcpu->mode, or we could miss a TLB
463 	 * flush request while the requester sees the VCPU as outside of guest
464 	 * mode and not needing an IPI.
465 	 */
466 	smp_store_mb(vcpu->mode, IN_GUEST_MODE);
467 
468 	r = kvm_mips_callbacks->vcpu_run(run, vcpu);
469 
470 	trace_kvm_out(vcpu);
471 	guest_exit_irqoff();
472 	local_irq_enable();
473 
474 out:
475 	kvm_sigset_deactivate(vcpu);
476 
477 	vcpu_put(vcpu);
478 	return r;
479 }
480 
kvm_vcpu_ioctl_interrupt(struct kvm_vcpu * vcpu,struct kvm_mips_interrupt * irq)481 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
482 			     struct kvm_mips_interrupt *irq)
483 {
484 	int intr = (int)irq->irq;
485 	struct kvm_vcpu *dvcpu = NULL;
486 
487 	if (intr == 3 || intr == -3 || intr == 4 || intr == -4)
488 		kvm_debug("%s: CPU: %d, INTR: %d\n", __func__, irq->cpu,
489 			  (int)intr);
490 
491 	if (irq->cpu == -1)
492 		dvcpu = vcpu;
493 	else
494 		dvcpu = vcpu->kvm->vcpus[irq->cpu];
495 
496 	if (intr == 2 || intr == 3 || intr == 4) {
497 		kvm_mips_callbacks->queue_io_int(dvcpu, irq);
498 
499 	} else if (intr == -2 || intr == -3 || intr == -4) {
500 		kvm_mips_callbacks->dequeue_io_int(dvcpu, irq);
501 	} else {
502 		kvm_err("%s: invalid interrupt ioctl (%d:%d)\n", __func__,
503 			irq->cpu, irq->irq);
504 		return -EINVAL;
505 	}
506 
507 	dvcpu->arch.wait = 0;
508 
509 	if (swq_has_sleeper(&dvcpu->wq))
510 		swake_up_one(&dvcpu->wq);
511 
512 	return 0;
513 }
514 
kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)515 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
516 				    struct kvm_mp_state *mp_state)
517 {
518 	return -ENOIOCTLCMD;
519 }
520 
kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)521 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
522 				    struct kvm_mp_state *mp_state)
523 {
524 	return -ENOIOCTLCMD;
525 }
526 
527 static u64 kvm_mips_get_one_regs[] = {
528 	KVM_REG_MIPS_R0,
529 	KVM_REG_MIPS_R1,
530 	KVM_REG_MIPS_R2,
531 	KVM_REG_MIPS_R3,
532 	KVM_REG_MIPS_R4,
533 	KVM_REG_MIPS_R5,
534 	KVM_REG_MIPS_R6,
535 	KVM_REG_MIPS_R7,
536 	KVM_REG_MIPS_R8,
537 	KVM_REG_MIPS_R9,
538 	KVM_REG_MIPS_R10,
539 	KVM_REG_MIPS_R11,
540 	KVM_REG_MIPS_R12,
541 	KVM_REG_MIPS_R13,
542 	KVM_REG_MIPS_R14,
543 	KVM_REG_MIPS_R15,
544 	KVM_REG_MIPS_R16,
545 	KVM_REG_MIPS_R17,
546 	KVM_REG_MIPS_R18,
547 	KVM_REG_MIPS_R19,
548 	KVM_REG_MIPS_R20,
549 	KVM_REG_MIPS_R21,
550 	KVM_REG_MIPS_R22,
551 	KVM_REG_MIPS_R23,
552 	KVM_REG_MIPS_R24,
553 	KVM_REG_MIPS_R25,
554 	KVM_REG_MIPS_R26,
555 	KVM_REG_MIPS_R27,
556 	KVM_REG_MIPS_R28,
557 	KVM_REG_MIPS_R29,
558 	KVM_REG_MIPS_R30,
559 	KVM_REG_MIPS_R31,
560 
561 #ifndef CONFIG_CPU_MIPSR6
562 	KVM_REG_MIPS_HI,
563 	KVM_REG_MIPS_LO,
564 #endif
565 	KVM_REG_MIPS_PC,
566 };
567 
568 static u64 kvm_mips_get_one_regs_fpu[] = {
569 	KVM_REG_MIPS_FCR_IR,
570 	KVM_REG_MIPS_FCR_CSR,
571 };
572 
573 static u64 kvm_mips_get_one_regs_msa[] = {
574 	KVM_REG_MIPS_MSA_IR,
575 	KVM_REG_MIPS_MSA_CSR,
576 };
577 
kvm_mips_num_regs(struct kvm_vcpu * vcpu)578 static unsigned long kvm_mips_num_regs(struct kvm_vcpu *vcpu)
579 {
580 	unsigned long ret;
581 
582 	ret = ARRAY_SIZE(kvm_mips_get_one_regs);
583 	if (kvm_mips_guest_can_have_fpu(&vcpu->arch)) {
584 		ret += ARRAY_SIZE(kvm_mips_get_one_regs_fpu) + 48;
585 		/* odd doubles */
586 		if (boot_cpu_data.fpu_id & MIPS_FPIR_F64)
587 			ret += 16;
588 	}
589 	if (kvm_mips_guest_can_have_msa(&vcpu->arch))
590 		ret += ARRAY_SIZE(kvm_mips_get_one_regs_msa) + 32;
591 	ret += kvm_mips_callbacks->num_regs(vcpu);
592 
593 	return ret;
594 }
595 
kvm_mips_copy_reg_indices(struct kvm_vcpu * vcpu,u64 __user * indices)596 static int kvm_mips_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices)
597 {
598 	u64 index;
599 	unsigned int i;
600 
601 	if (copy_to_user(indices, kvm_mips_get_one_regs,
602 			 sizeof(kvm_mips_get_one_regs)))
603 		return -EFAULT;
604 	indices += ARRAY_SIZE(kvm_mips_get_one_regs);
605 
606 	if (kvm_mips_guest_can_have_fpu(&vcpu->arch)) {
607 		if (copy_to_user(indices, kvm_mips_get_one_regs_fpu,
608 				 sizeof(kvm_mips_get_one_regs_fpu)))
609 			return -EFAULT;
610 		indices += ARRAY_SIZE(kvm_mips_get_one_regs_fpu);
611 
612 		for (i = 0; i < 32; ++i) {
613 			index = KVM_REG_MIPS_FPR_32(i);
614 			if (copy_to_user(indices, &index, sizeof(index)))
615 				return -EFAULT;
616 			++indices;
617 
618 			/* skip odd doubles if no F64 */
619 			if (i & 1 && !(boot_cpu_data.fpu_id & MIPS_FPIR_F64))
620 				continue;
621 
622 			index = KVM_REG_MIPS_FPR_64(i);
623 			if (copy_to_user(indices, &index, sizeof(index)))
624 				return -EFAULT;
625 			++indices;
626 		}
627 	}
628 
629 	if (kvm_mips_guest_can_have_msa(&vcpu->arch)) {
630 		if (copy_to_user(indices, kvm_mips_get_one_regs_msa,
631 				 sizeof(kvm_mips_get_one_regs_msa)))
632 			return -EFAULT;
633 		indices += ARRAY_SIZE(kvm_mips_get_one_regs_msa);
634 
635 		for (i = 0; i < 32; ++i) {
636 			index = KVM_REG_MIPS_VEC_128(i);
637 			if (copy_to_user(indices, &index, sizeof(index)))
638 				return -EFAULT;
639 			++indices;
640 		}
641 	}
642 
643 	return kvm_mips_callbacks->copy_reg_indices(vcpu, indices);
644 }
645 
kvm_mips_get_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)646 static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
647 			    const struct kvm_one_reg *reg)
648 {
649 	struct mips_coproc *cop0 = vcpu->arch.cop0;
650 	struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
651 	int ret;
652 	s64 v;
653 	s64 vs[2];
654 	unsigned int idx;
655 
656 	switch (reg->id) {
657 	/* General purpose registers */
658 	case KVM_REG_MIPS_R0 ... KVM_REG_MIPS_R31:
659 		v = (long)vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0];
660 		break;
661 #ifndef CONFIG_CPU_MIPSR6
662 	case KVM_REG_MIPS_HI:
663 		v = (long)vcpu->arch.hi;
664 		break;
665 	case KVM_REG_MIPS_LO:
666 		v = (long)vcpu->arch.lo;
667 		break;
668 #endif
669 	case KVM_REG_MIPS_PC:
670 		v = (long)vcpu->arch.pc;
671 		break;
672 
673 	/* Floating point registers */
674 	case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
675 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
676 			return -EINVAL;
677 		idx = reg->id - KVM_REG_MIPS_FPR_32(0);
678 		/* Odd singles in top of even double when FR=0 */
679 		if (kvm_read_c0_guest_status(cop0) & ST0_FR)
680 			v = get_fpr32(&fpu->fpr[idx], 0);
681 		else
682 			v = get_fpr32(&fpu->fpr[idx & ~1], idx & 1);
683 		break;
684 	case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
685 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
686 			return -EINVAL;
687 		idx = reg->id - KVM_REG_MIPS_FPR_64(0);
688 		/* Can't access odd doubles in FR=0 mode */
689 		if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
690 			return -EINVAL;
691 		v = get_fpr64(&fpu->fpr[idx], 0);
692 		break;
693 	case KVM_REG_MIPS_FCR_IR:
694 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
695 			return -EINVAL;
696 		v = boot_cpu_data.fpu_id;
697 		break;
698 	case KVM_REG_MIPS_FCR_CSR:
699 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
700 			return -EINVAL;
701 		v = fpu->fcr31;
702 		break;
703 
704 	/* MIPS SIMD Architecture (MSA) registers */
705 	case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
706 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
707 			return -EINVAL;
708 		/* Can't access MSA registers in FR=0 mode */
709 		if (!(kvm_read_c0_guest_status(cop0) & ST0_FR))
710 			return -EINVAL;
711 		idx = reg->id - KVM_REG_MIPS_VEC_128(0);
712 #ifdef CONFIG_CPU_LITTLE_ENDIAN
713 		/* least significant byte first */
714 		vs[0] = get_fpr64(&fpu->fpr[idx], 0);
715 		vs[1] = get_fpr64(&fpu->fpr[idx], 1);
716 #else
717 		/* most significant byte first */
718 		vs[0] = get_fpr64(&fpu->fpr[idx], 1);
719 		vs[1] = get_fpr64(&fpu->fpr[idx], 0);
720 #endif
721 		break;
722 	case KVM_REG_MIPS_MSA_IR:
723 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
724 			return -EINVAL;
725 		v = boot_cpu_data.msa_id;
726 		break;
727 	case KVM_REG_MIPS_MSA_CSR:
728 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
729 			return -EINVAL;
730 		v = fpu->msacsr;
731 		break;
732 
733 	/* registers to be handled specially */
734 	default:
735 		ret = kvm_mips_callbacks->get_one_reg(vcpu, reg, &v);
736 		if (ret)
737 			return ret;
738 		break;
739 	}
740 	if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
741 		u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
742 
743 		return put_user(v, uaddr64);
744 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
745 		u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
746 		u32 v32 = (u32)v;
747 
748 		return put_user(v32, uaddr32);
749 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
750 		void __user *uaddr = (void __user *)(long)reg->addr;
751 
752 		return copy_to_user(uaddr, vs, 16) ? -EFAULT : 0;
753 	} else {
754 		return -EINVAL;
755 	}
756 }
757 
kvm_mips_set_reg(struct kvm_vcpu * vcpu,const struct kvm_one_reg * reg)758 static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
759 			    const struct kvm_one_reg *reg)
760 {
761 	struct mips_coproc *cop0 = vcpu->arch.cop0;
762 	struct mips_fpu_struct *fpu = &vcpu->arch.fpu;
763 	s64 v;
764 	s64 vs[2];
765 	unsigned int idx;
766 
767 	if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U64) {
768 		u64 __user *uaddr64 = (u64 __user *)(long)reg->addr;
769 
770 		if (get_user(v, uaddr64) != 0)
771 			return -EFAULT;
772 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U32) {
773 		u32 __user *uaddr32 = (u32 __user *)(long)reg->addr;
774 		s32 v32;
775 
776 		if (get_user(v32, uaddr32) != 0)
777 			return -EFAULT;
778 		v = (s64)v32;
779 	} else if ((reg->id & KVM_REG_SIZE_MASK) == KVM_REG_SIZE_U128) {
780 		void __user *uaddr = (void __user *)(long)reg->addr;
781 
782 		return copy_from_user(vs, uaddr, 16) ? -EFAULT : 0;
783 	} else {
784 		return -EINVAL;
785 	}
786 
787 	switch (reg->id) {
788 	/* General purpose registers */
789 	case KVM_REG_MIPS_R0:
790 		/* Silently ignore requests to set $0 */
791 		break;
792 	case KVM_REG_MIPS_R1 ... KVM_REG_MIPS_R31:
793 		vcpu->arch.gprs[reg->id - KVM_REG_MIPS_R0] = v;
794 		break;
795 #ifndef CONFIG_CPU_MIPSR6
796 	case KVM_REG_MIPS_HI:
797 		vcpu->arch.hi = v;
798 		break;
799 	case KVM_REG_MIPS_LO:
800 		vcpu->arch.lo = v;
801 		break;
802 #endif
803 	case KVM_REG_MIPS_PC:
804 		vcpu->arch.pc = v;
805 		break;
806 
807 	/* Floating point registers */
808 	case KVM_REG_MIPS_FPR_32(0) ... KVM_REG_MIPS_FPR_32(31):
809 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
810 			return -EINVAL;
811 		idx = reg->id - KVM_REG_MIPS_FPR_32(0);
812 		/* Odd singles in top of even double when FR=0 */
813 		if (kvm_read_c0_guest_status(cop0) & ST0_FR)
814 			set_fpr32(&fpu->fpr[idx], 0, v);
815 		else
816 			set_fpr32(&fpu->fpr[idx & ~1], idx & 1, v);
817 		break;
818 	case KVM_REG_MIPS_FPR_64(0) ... KVM_REG_MIPS_FPR_64(31):
819 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
820 			return -EINVAL;
821 		idx = reg->id - KVM_REG_MIPS_FPR_64(0);
822 		/* Can't access odd doubles in FR=0 mode */
823 		if (idx & 1 && !(kvm_read_c0_guest_status(cop0) & ST0_FR))
824 			return -EINVAL;
825 		set_fpr64(&fpu->fpr[idx], 0, v);
826 		break;
827 	case KVM_REG_MIPS_FCR_IR:
828 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
829 			return -EINVAL;
830 		/* Read-only */
831 		break;
832 	case KVM_REG_MIPS_FCR_CSR:
833 		if (!kvm_mips_guest_has_fpu(&vcpu->arch))
834 			return -EINVAL;
835 		fpu->fcr31 = v;
836 		break;
837 
838 	/* MIPS SIMD Architecture (MSA) registers */
839 	case KVM_REG_MIPS_VEC_128(0) ... KVM_REG_MIPS_VEC_128(31):
840 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
841 			return -EINVAL;
842 		idx = reg->id - KVM_REG_MIPS_VEC_128(0);
843 #ifdef CONFIG_CPU_LITTLE_ENDIAN
844 		/* least significant byte first */
845 		set_fpr64(&fpu->fpr[idx], 0, vs[0]);
846 		set_fpr64(&fpu->fpr[idx], 1, vs[1]);
847 #else
848 		/* most significant byte first */
849 		set_fpr64(&fpu->fpr[idx], 1, vs[0]);
850 		set_fpr64(&fpu->fpr[idx], 0, vs[1]);
851 #endif
852 		break;
853 	case KVM_REG_MIPS_MSA_IR:
854 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
855 			return -EINVAL;
856 		/* Read-only */
857 		break;
858 	case KVM_REG_MIPS_MSA_CSR:
859 		if (!kvm_mips_guest_has_msa(&vcpu->arch))
860 			return -EINVAL;
861 		fpu->msacsr = v;
862 		break;
863 
864 	/* registers to be handled specially */
865 	default:
866 		return kvm_mips_callbacks->set_one_reg(vcpu, reg, v);
867 	}
868 	return 0;
869 }
870 
kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu * vcpu,struct kvm_enable_cap * cap)871 static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
872 				     struct kvm_enable_cap *cap)
873 {
874 	int r = 0;
875 
876 	if (!kvm_vm_ioctl_check_extension(vcpu->kvm, cap->cap))
877 		return -EINVAL;
878 	if (cap->flags)
879 		return -EINVAL;
880 	if (cap->args[0])
881 		return -EINVAL;
882 
883 	switch (cap->cap) {
884 	case KVM_CAP_MIPS_FPU:
885 		vcpu->arch.fpu_enabled = true;
886 		break;
887 	case KVM_CAP_MIPS_MSA:
888 		vcpu->arch.msa_enabled = true;
889 		break;
890 	default:
891 		r = -EINVAL;
892 		break;
893 	}
894 
895 	return r;
896 }
897 
kvm_arch_vcpu_async_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)898 long kvm_arch_vcpu_async_ioctl(struct file *filp, unsigned int ioctl,
899 			       unsigned long arg)
900 {
901 	struct kvm_vcpu *vcpu = filp->private_data;
902 	void __user *argp = (void __user *)arg;
903 
904 	if (ioctl == KVM_INTERRUPT) {
905 		struct kvm_mips_interrupt irq;
906 
907 		if (copy_from_user(&irq, argp, sizeof(irq)))
908 			return -EFAULT;
909 		kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__,
910 			  irq.irq);
911 
912 		return kvm_vcpu_ioctl_interrupt(vcpu, &irq);
913 	}
914 
915 	return -ENOIOCTLCMD;
916 }
917 
kvm_arch_vcpu_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)918 long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl,
919 			 unsigned long arg)
920 {
921 	struct kvm_vcpu *vcpu = filp->private_data;
922 	void __user *argp = (void __user *)arg;
923 	long r;
924 
925 	vcpu_load(vcpu);
926 
927 	switch (ioctl) {
928 	case KVM_SET_ONE_REG:
929 	case KVM_GET_ONE_REG: {
930 		struct kvm_one_reg reg;
931 
932 		r = -EFAULT;
933 		if (copy_from_user(&reg, argp, sizeof(reg)))
934 			break;
935 		if (ioctl == KVM_SET_ONE_REG)
936 			r = kvm_mips_set_reg(vcpu, &reg);
937 		else
938 			r = kvm_mips_get_reg(vcpu, &reg);
939 		break;
940 	}
941 	case KVM_GET_REG_LIST: {
942 		struct kvm_reg_list __user *user_list = argp;
943 		struct kvm_reg_list reg_list;
944 		unsigned n;
945 
946 		r = -EFAULT;
947 		if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
948 			break;
949 		n = reg_list.n;
950 		reg_list.n = kvm_mips_num_regs(vcpu);
951 		if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
952 			break;
953 		r = -E2BIG;
954 		if (n < reg_list.n)
955 			break;
956 		r = kvm_mips_copy_reg_indices(vcpu, user_list->reg);
957 		break;
958 	}
959 	case KVM_ENABLE_CAP: {
960 		struct kvm_enable_cap cap;
961 
962 		r = -EFAULT;
963 		if (copy_from_user(&cap, argp, sizeof(cap)))
964 			break;
965 		r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
966 		break;
967 	}
968 	default:
969 		r = -ENOIOCTLCMD;
970 	}
971 
972 	vcpu_put(vcpu);
973 	return r;
974 }
975 
976 /**
977  * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
978  * @kvm: kvm instance
979  * @log: slot id and address to which we copy the log
980  *
981  * Steps 1-4 below provide general overview of dirty page logging. See
982  * kvm_get_dirty_log_protect() function description for additional details.
983  *
984  * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
985  * always flush the TLB (step 4) even if previous step failed  and the dirty
986  * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
987  * does not preclude user space subsequent dirty log read. Flushing TLB ensures
988  * writes will be marked dirty for next log read.
989  *
990  *   1. Take a snapshot of the bit and clear it if needed.
991  *   2. Write protect the corresponding page.
992  *   3. Copy the snapshot to the userspace.
993  *   4. Flush TLB's if needed.
994  */
kvm_vm_ioctl_get_dirty_log(struct kvm * kvm,struct kvm_dirty_log * log)995 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
996 {
997 	struct kvm_memslots *slots;
998 	struct kvm_memory_slot *memslot;
999 	bool flush = false;
1000 	int r;
1001 
1002 	mutex_lock(&kvm->slots_lock);
1003 
1004 	r = kvm_get_dirty_log_protect(kvm, log, &flush);
1005 
1006 	if (flush) {
1007 		slots = kvm_memslots(kvm);
1008 		memslot = id_to_memslot(slots, log->slot);
1009 
1010 		/* Let implementation handle TLB/GVA invalidation */
1011 		kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot);
1012 	}
1013 
1014 	mutex_unlock(&kvm->slots_lock);
1015 	return r;
1016 }
1017 
kvm_vm_ioctl_clear_dirty_log(struct kvm * kvm,struct kvm_clear_dirty_log * log)1018 int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, struct kvm_clear_dirty_log *log)
1019 {
1020 	struct kvm_memslots *slots;
1021 	struct kvm_memory_slot *memslot;
1022 	bool flush = false;
1023 	int r;
1024 
1025 	mutex_lock(&kvm->slots_lock);
1026 
1027 	r = kvm_clear_dirty_log_protect(kvm, log, &flush);
1028 
1029 	if (flush) {
1030 		slots = kvm_memslots(kvm);
1031 		memslot = id_to_memslot(slots, log->slot);
1032 
1033 		/* Let implementation handle TLB/GVA invalidation */
1034 		kvm_mips_callbacks->flush_shadow_memslot(kvm, memslot);
1035 	}
1036 
1037 	mutex_unlock(&kvm->slots_lock);
1038 	return r;
1039 }
1040 
kvm_arch_vm_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)1041 long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
1042 {
1043 	long r;
1044 
1045 	switch (ioctl) {
1046 	default:
1047 		r = -ENOIOCTLCMD;
1048 	}
1049 
1050 	return r;
1051 }
1052 
kvm_arch_init(void * opaque)1053 int kvm_arch_init(void *opaque)
1054 {
1055 	if (kvm_mips_callbacks) {
1056 		kvm_err("kvm: module already exists\n");
1057 		return -EEXIST;
1058 	}
1059 
1060 	return kvm_mips_emulation_init(&kvm_mips_callbacks);
1061 }
1062 
kvm_arch_exit(void)1063 void kvm_arch_exit(void)
1064 {
1065 	kvm_mips_callbacks = NULL;
1066 }
1067 
kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu * vcpu,struct kvm_sregs * sregs)1068 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
1069 				  struct kvm_sregs *sregs)
1070 {
1071 	return -ENOIOCTLCMD;
1072 }
1073 
kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu * vcpu,struct kvm_sregs * sregs)1074 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
1075 				  struct kvm_sregs *sregs)
1076 {
1077 	return -ENOIOCTLCMD;
1078 }
1079 
kvm_arch_vcpu_postcreate(struct kvm_vcpu * vcpu)1080 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
1081 {
1082 }
1083 
kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu * vcpu,struct kvm_fpu * fpu)1084 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
1085 {
1086 	return -ENOIOCTLCMD;
1087 }
1088 
kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu * vcpu,struct kvm_fpu * fpu)1089 int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
1090 {
1091 	return -ENOIOCTLCMD;
1092 }
1093 
kvm_arch_vcpu_fault(struct kvm_vcpu * vcpu,struct vm_fault * vmf)1094 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
1095 {
1096 	return VM_FAULT_SIGBUS;
1097 }
1098 
kvm_vm_ioctl_check_extension(struct kvm * kvm,long ext)1099 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
1100 {
1101 	int r;
1102 
1103 	switch (ext) {
1104 	case KVM_CAP_ONE_REG:
1105 	case KVM_CAP_ENABLE_CAP:
1106 	case KVM_CAP_READONLY_MEM:
1107 	case KVM_CAP_SYNC_MMU:
1108 	case KVM_CAP_IMMEDIATE_EXIT:
1109 		r = 1;
1110 		break;
1111 	case KVM_CAP_NR_VCPUS:
1112 		r = num_online_cpus();
1113 		break;
1114 	case KVM_CAP_MAX_VCPUS:
1115 		r = KVM_MAX_VCPUS;
1116 		break;
1117 	case KVM_CAP_MAX_VCPU_ID:
1118 		r = KVM_MAX_VCPU_ID;
1119 		break;
1120 	case KVM_CAP_MIPS_FPU:
1121 		/* We don't handle systems with inconsistent cpu_has_fpu */
1122 		r = !!raw_cpu_has_fpu;
1123 		break;
1124 	case KVM_CAP_MIPS_MSA:
1125 		/*
1126 		 * We don't support MSA vector partitioning yet:
1127 		 * 1) It would require explicit support which can't be tested
1128 		 *    yet due to lack of support in current hardware.
1129 		 * 2) It extends the state that would need to be saved/restored
1130 		 *    by e.g. QEMU for migration.
1131 		 *
1132 		 * When vector partitioning hardware becomes available, support
1133 		 * could be added by requiring a flag when enabling
1134 		 * KVM_CAP_MIPS_MSA capability to indicate that userland knows
1135 		 * to save/restore the appropriate extra state.
1136 		 */
1137 		r = cpu_has_msa && !(boot_cpu_data.msa_id & MSA_IR_WRPF);
1138 		break;
1139 	default:
1140 		r = kvm_mips_callbacks->check_extension(kvm, ext);
1141 		break;
1142 	}
1143 	return r;
1144 }
1145 
kvm_cpu_has_pending_timer(struct kvm_vcpu * vcpu)1146 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
1147 {
1148 	return kvm_mips_pending_timer(vcpu) ||
1149 		kvm_read_c0_guest_cause(vcpu->arch.cop0) & C_TI;
1150 }
1151 
kvm_arch_vcpu_dump_regs(struct kvm_vcpu * vcpu)1152 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
1153 {
1154 	int i;
1155 	struct mips_coproc *cop0;
1156 
1157 	if (!vcpu)
1158 		return -1;
1159 
1160 	kvm_debug("VCPU Register Dump:\n");
1161 	kvm_debug("\tpc = 0x%08lx\n", vcpu->arch.pc);
1162 	kvm_debug("\texceptions: %08lx\n", vcpu->arch.pending_exceptions);
1163 
1164 	for (i = 0; i < 32; i += 4) {
1165 		kvm_debug("\tgpr%02d: %08lx %08lx %08lx %08lx\n", i,
1166 		       vcpu->arch.gprs[i],
1167 		       vcpu->arch.gprs[i + 1],
1168 		       vcpu->arch.gprs[i + 2], vcpu->arch.gprs[i + 3]);
1169 	}
1170 	kvm_debug("\thi: 0x%08lx\n", vcpu->arch.hi);
1171 	kvm_debug("\tlo: 0x%08lx\n", vcpu->arch.lo);
1172 
1173 	cop0 = vcpu->arch.cop0;
1174 	kvm_debug("\tStatus: 0x%08x, Cause: 0x%08x\n",
1175 		  kvm_read_c0_guest_status(cop0),
1176 		  kvm_read_c0_guest_cause(cop0));
1177 
1178 	kvm_debug("\tEPC: 0x%08lx\n", kvm_read_c0_guest_epc(cop0));
1179 
1180 	return 0;
1181 }
1182 
kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu * vcpu,struct kvm_regs * regs)1183 int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
1184 {
1185 	int i;
1186 
1187 	vcpu_load(vcpu);
1188 
1189 	for (i = 1; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
1190 		vcpu->arch.gprs[i] = regs->gpr[i];
1191 	vcpu->arch.gprs[0] = 0; /* zero is special, and cannot be set. */
1192 	vcpu->arch.hi = regs->hi;
1193 	vcpu->arch.lo = regs->lo;
1194 	vcpu->arch.pc = regs->pc;
1195 
1196 	vcpu_put(vcpu);
1197 	return 0;
1198 }
1199 
kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu * vcpu,struct kvm_regs * regs)1200 int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
1201 {
1202 	int i;
1203 
1204 	vcpu_load(vcpu);
1205 
1206 	for (i = 0; i < ARRAY_SIZE(vcpu->arch.gprs); i++)
1207 		regs->gpr[i] = vcpu->arch.gprs[i];
1208 
1209 	regs->hi = vcpu->arch.hi;
1210 	regs->lo = vcpu->arch.lo;
1211 	regs->pc = vcpu->arch.pc;
1212 
1213 	vcpu_put(vcpu);
1214 	return 0;
1215 }
1216 
kvm_mips_comparecount_func(unsigned long data)1217 static void kvm_mips_comparecount_func(unsigned long data)
1218 {
1219 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
1220 
1221 	kvm_mips_callbacks->queue_timer_int(vcpu);
1222 
1223 	vcpu->arch.wait = 0;
1224 	if (swq_has_sleeper(&vcpu->wq))
1225 		swake_up_one(&vcpu->wq);
1226 }
1227 
1228 /* low level hrtimer wake routine */
kvm_mips_comparecount_wakeup(struct hrtimer * timer)1229 static enum hrtimer_restart kvm_mips_comparecount_wakeup(struct hrtimer *timer)
1230 {
1231 	struct kvm_vcpu *vcpu;
1232 
1233 	vcpu = container_of(timer, struct kvm_vcpu, arch.comparecount_timer);
1234 	kvm_mips_comparecount_func((unsigned long) vcpu);
1235 	return kvm_mips_count_timeout(vcpu);
1236 }
1237 
kvm_arch_vcpu_init(struct kvm_vcpu * vcpu)1238 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
1239 {
1240 	int err;
1241 
1242 	err = kvm_mips_callbacks->vcpu_init(vcpu);
1243 	if (err)
1244 		return err;
1245 
1246 	hrtimer_init(&vcpu->arch.comparecount_timer, CLOCK_MONOTONIC,
1247 		     HRTIMER_MODE_REL);
1248 	vcpu->arch.comparecount_timer.function = kvm_mips_comparecount_wakeup;
1249 	return 0;
1250 }
1251 
kvm_arch_vcpu_uninit(struct kvm_vcpu * vcpu)1252 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
1253 {
1254 	kvm_mips_callbacks->vcpu_uninit(vcpu);
1255 }
1256 
kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu * vcpu,struct kvm_translation * tr)1257 int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
1258 				  struct kvm_translation *tr)
1259 {
1260 	return 0;
1261 }
1262 
1263 /* Initial guest state */
kvm_arch_vcpu_setup(struct kvm_vcpu * vcpu)1264 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
1265 {
1266 	return kvm_mips_callbacks->vcpu_setup(vcpu);
1267 }
1268 
kvm_mips_set_c0_status(void)1269 static void kvm_mips_set_c0_status(void)
1270 {
1271 	u32 status = read_c0_status();
1272 
1273 	if (cpu_has_dsp)
1274 		status |= (ST0_MX);
1275 
1276 	write_c0_status(status);
1277 	ehb();
1278 }
1279 
1280 /*
1281  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
1282  */
kvm_mips_handle_exit(struct kvm_run * run,struct kvm_vcpu * vcpu)1283 int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
1284 {
1285 	u32 cause = vcpu->arch.host_cp0_cause;
1286 	u32 exccode = (cause >> CAUSEB_EXCCODE) & 0x1f;
1287 	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
1288 	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
1289 	enum emulation_result er = EMULATE_DONE;
1290 	u32 inst;
1291 	int ret = RESUME_GUEST;
1292 
1293 	vcpu->mode = OUTSIDE_GUEST_MODE;
1294 
1295 	/* re-enable HTW before enabling interrupts */
1296 	if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ))
1297 		htw_start();
1298 
1299 	/* Set a default exit reason */
1300 	run->exit_reason = KVM_EXIT_UNKNOWN;
1301 	run->ready_for_interrupt_injection = 1;
1302 
1303 	/*
1304 	 * Set the appropriate status bits based on host CPU features,
1305 	 * before we hit the scheduler
1306 	 */
1307 	kvm_mips_set_c0_status();
1308 
1309 	local_irq_enable();
1310 
1311 	kvm_debug("kvm_mips_handle_exit: cause: %#x, PC: %p, kvm_run: %p, kvm_vcpu: %p\n",
1312 			cause, opc, run, vcpu);
1313 	trace_kvm_exit(vcpu, exccode);
1314 
1315 	if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) {
1316 		/*
1317 		 * Do a privilege check, if in UM most of these exit conditions
1318 		 * end up causing an exception to be delivered to the Guest
1319 		 * Kernel
1320 		 */
1321 		er = kvm_mips_check_privilege(cause, opc, run, vcpu);
1322 		if (er == EMULATE_PRIV_FAIL) {
1323 			goto skip_emul;
1324 		} else if (er == EMULATE_FAIL) {
1325 			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1326 			ret = RESUME_HOST;
1327 			goto skip_emul;
1328 		}
1329 	}
1330 
1331 	switch (exccode) {
1332 	case EXCCODE_INT:
1333 		kvm_debug("[%d]EXCCODE_INT @ %p\n", vcpu->vcpu_id, opc);
1334 
1335 		++vcpu->stat.int_exits;
1336 
1337 		if (need_resched())
1338 			cond_resched();
1339 
1340 		ret = RESUME_GUEST;
1341 		break;
1342 
1343 	case EXCCODE_CPU:
1344 		kvm_debug("EXCCODE_CPU: @ PC: %p\n", opc);
1345 
1346 		++vcpu->stat.cop_unusable_exits;
1347 		ret = kvm_mips_callbacks->handle_cop_unusable(vcpu);
1348 		/* XXXKYMA: Might need to return to user space */
1349 		if (run->exit_reason == KVM_EXIT_IRQ_WINDOW_OPEN)
1350 			ret = RESUME_HOST;
1351 		break;
1352 
1353 	case EXCCODE_MOD:
1354 		++vcpu->stat.tlbmod_exits;
1355 		ret = kvm_mips_callbacks->handle_tlb_mod(vcpu);
1356 		break;
1357 
1358 	case EXCCODE_TLBS:
1359 		kvm_debug("TLB ST fault:  cause %#x, status %#x, PC: %p, BadVaddr: %#lx\n",
1360 			  cause, kvm_read_c0_guest_status(vcpu->arch.cop0), opc,
1361 			  badvaddr);
1362 
1363 		++vcpu->stat.tlbmiss_st_exits;
1364 		ret = kvm_mips_callbacks->handle_tlb_st_miss(vcpu);
1365 		break;
1366 
1367 	case EXCCODE_TLBL:
1368 		kvm_debug("TLB LD fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
1369 			  cause, opc, badvaddr);
1370 
1371 		++vcpu->stat.tlbmiss_ld_exits;
1372 		ret = kvm_mips_callbacks->handle_tlb_ld_miss(vcpu);
1373 		break;
1374 
1375 	case EXCCODE_ADES:
1376 		++vcpu->stat.addrerr_st_exits;
1377 		ret = kvm_mips_callbacks->handle_addr_err_st(vcpu);
1378 		break;
1379 
1380 	case EXCCODE_ADEL:
1381 		++vcpu->stat.addrerr_ld_exits;
1382 		ret = kvm_mips_callbacks->handle_addr_err_ld(vcpu);
1383 		break;
1384 
1385 	case EXCCODE_SYS:
1386 		++vcpu->stat.syscall_exits;
1387 		ret = kvm_mips_callbacks->handle_syscall(vcpu);
1388 		break;
1389 
1390 	case EXCCODE_RI:
1391 		++vcpu->stat.resvd_inst_exits;
1392 		ret = kvm_mips_callbacks->handle_res_inst(vcpu);
1393 		break;
1394 
1395 	case EXCCODE_BP:
1396 		++vcpu->stat.break_inst_exits;
1397 		ret = kvm_mips_callbacks->handle_break(vcpu);
1398 		break;
1399 
1400 	case EXCCODE_TR:
1401 		++vcpu->stat.trap_inst_exits;
1402 		ret = kvm_mips_callbacks->handle_trap(vcpu);
1403 		break;
1404 
1405 	case EXCCODE_MSAFPE:
1406 		++vcpu->stat.msa_fpe_exits;
1407 		ret = kvm_mips_callbacks->handle_msa_fpe(vcpu);
1408 		break;
1409 
1410 	case EXCCODE_FPE:
1411 		++vcpu->stat.fpe_exits;
1412 		ret = kvm_mips_callbacks->handle_fpe(vcpu);
1413 		break;
1414 
1415 	case EXCCODE_MSADIS:
1416 		++vcpu->stat.msa_disabled_exits;
1417 		ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
1418 		break;
1419 
1420 	case EXCCODE_GE:
1421 		/* defer exit accounting to handler */
1422 		ret = kvm_mips_callbacks->handle_guest_exit(vcpu);
1423 		break;
1424 
1425 	default:
1426 		if (cause & CAUSEF_BD)
1427 			opc += 1;
1428 		inst = 0;
1429 		kvm_get_badinstr(opc, vcpu, &inst);
1430 		kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x  BadVaddr: %#lx Status: %#x\n",
1431 			exccode, opc, inst, badvaddr,
1432 			kvm_read_c0_guest_status(vcpu->arch.cop0));
1433 		kvm_arch_vcpu_dump_regs(vcpu);
1434 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
1435 		ret = RESUME_HOST;
1436 		break;
1437 
1438 	}
1439 
1440 skip_emul:
1441 	local_irq_disable();
1442 
1443 	if (ret == RESUME_GUEST)
1444 		kvm_vz_acquire_htimer(vcpu);
1445 
1446 	if (er == EMULATE_DONE && !(ret & RESUME_HOST))
1447 		kvm_mips_deliver_interrupts(vcpu, cause);
1448 
1449 	if (!(ret & RESUME_HOST)) {
1450 		/* Only check for signals if not already exiting to userspace */
1451 		if (signal_pending(current)) {
1452 			run->exit_reason = KVM_EXIT_INTR;
1453 			ret = (-EINTR << 2) | RESUME_HOST;
1454 			++vcpu->stat.signal_exits;
1455 			trace_kvm_exit(vcpu, KVM_TRACE_EXIT_SIGNAL);
1456 		}
1457 	}
1458 
1459 	if (ret == RESUME_GUEST) {
1460 		trace_kvm_reenter(vcpu);
1461 
1462 		/*
1463 		 * Make sure the read of VCPU requests in vcpu_reenter()
1464 		 * callback is not reordered ahead of the write to vcpu->mode,
1465 		 * or we could miss a TLB flush request while the requester sees
1466 		 * the VCPU as outside of guest mode and not needing an IPI.
1467 		 */
1468 		smp_store_mb(vcpu->mode, IN_GUEST_MODE);
1469 
1470 		kvm_mips_callbacks->vcpu_reenter(run, vcpu);
1471 
1472 		/*
1473 		 * If FPU / MSA are enabled (i.e. the guest's FPU / MSA context
1474 		 * is live), restore FCR31 / MSACSR.
1475 		 *
1476 		 * This should be before returning to the guest exception
1477 		 * vector, as it may well cause an [MSA] FP exception if there
1478 		 * are pending exception bits unmasked. (see
1479 		 * kvm_mips_csr_die_notifier() for how that is handled).
1480 		 */
1481 		if (kvm_mips_guest_has_fpu(&vcpu->arch) &&
1482 		    read_c0_status() & ST0_CU1)
1483 			__kvm_restore_fcsr(&vcpu->arch);
1484 
1485 		if (kvm_mips_guest_has_msa(&vcpu->arch) &&
1486 		    read_c0_config5() & MIPS_CONF5_MSAEN)
1487 			__kvm_restore_msacsr(&vcpu->arch);
1488 	}
1489 
1490 	/* Disable HTW before returning to guest or host */
1491 	if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ))
1492 		htw_stop();
1493 
1494 	return ret;
1495 }
1496 
1497 /* Enable FPU for guest and restore context */
kvm_own_fpu(struct kvm_vcpu * vcpu)1498 void kvm_own_fpu(struct kvm_vcpu *vcpu)
1499 {
1500 	struct mips_coproc *cop0 = vcpu->arch.cop0;
1501 	unsigned int sr, cfg5;
1502 
1503 	preempt_disable();
1504 
1505 	sr = kvm_read_c0_guest_status(cop0);
1506 
1507 	/*
1508 	 * If MSA state is already live, it is undefined how it interacts with
1509 	 * FR=0 FPU state, and we don't want to hit reserved instruction
1510 	 * exceptions trying to save the MSA state later when CU=1 && FR=1, so
1511 	 * play it safe and save it first.
1512 	 *
1513 	 * In theory we shouldn't ever hit this case since kvm_lose_fpu() should
1514 	 * get called when guest CU1 is set, however we can't trust the guest
1515 	 * not to clobber the status register directly via the commpage.
1516 	 */
1517 	if (cpu_has_msa && sr & ST0_CU1 && !(sr & ST0_FR) &&
1518 	    vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA)
1519 		kvm_lose_fpu(vcpu);
1520 
1521 	/*
1522 	 * Enable FPU for guest
1523 	 * We set FR and FRE according to guest context
1524 	 */
1525 	change_c0_status(ST0_CU1 | ST0_FR, sr);
1526 	if (cpu_has_fre) {
1527 		cfg5 = kvm_read_c0_guest_config5(cop0);
1528 		change_c0_config5(MIPS_CONF5_FRE, cfg5);
1529 	}
1530 	enable_fpu_hazard();
1531 
1532 	/* If guest FPU state not active, restore it now */
1533 	if (!(vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)) {
1534 		__kvm_restore_fpu(&vcpu->arch);
1535 		vcpu->arch.aux_inuse |= KVM_MIPS_AUX_FPU;
1536 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_FPU);
1537 	} else {
1538 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_ENABLE, KVM_TRACE_AUX_FPU);
1539 	}
1540 
1541 	preempt_enable();
1542 }
1543 
1544 #ifdef CONFIG_CPU_HAS_MSA
1545 /* Enable MSA for guest and restore context */
kvm_own_msa(struct kvm_vcpu * vcpu)1546 void kvm_own_msa(struct kvm_vcpu *vcpu)
1547 {
1548 	struct mips_coproc *cop0 = vcpu->arch.cop0;
1549 	unsigned int sr, cfg5;
1550 
1551 	preempt_disable();
1552 
1553 	/*
1554 	 * Enable FPU if enabled in guest, since we're restoring FPU context
1555 	 * anyway. We set FR and FRE according to guest context.
1556 	 */
1557 	if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
1558 		sr = kvm_read_c0_guest_status(cop0);
1559 
1560 		/*
1561 		 * If FR=0 FPU state is already live, it is undefined how it
1562 		 * interacts with MSA state, so play it safe and save it first.
1563 		 */
1564 		if (!(sr & ST0_FR) &&
1565 		    (vcpu->arch.aux_inuse & (KVM_MIPS_AUX_FPU |
1566 				KVM_MIPS_AUX_MSA)) == KVM_MIPS_AUX_FPU)
1567 			kvm_lose_fpu(vcpu);
1568 
1569 		change_c0_status(ST0_CU1 | ST0_FR, sr);
1570 		if (sr & ST0_CU1 && cpu_has_fre) {
1571 			cfg5 = kvm_read_c0_guest_config5(cop0);
1572 			change_c0_config5(MIPS_CONF5_FRE, cfg5);
1573 		}
1574 	}
1575 
1576 	/* Enable MSA for guest */
1577 	set_c0_config5(MIPS_CONF5_MSAEN);
1578 	enable_fpu_hazard();
1579 
1580 	switch (vcpu->arch.aux_inuse & (KVM_MIPS_AUX_FPU | KVM_MIPS_AUX_MSA)) {
1581 	case KVM_MIPS_AUX_FPU:
1582 		/*
1583 		 * Guest FPU state already loaded, only restore upper MSA state
1584 		 */
1585 		__kvm_restore_msa_upper(&vcpu->arch);
1586 		vcpu->arch.aux_inuse |= KVM_MIPS_AUX_MSA;
1587 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_MSA);
1588 		break;
1589 	case 0:
1590 		/* Neither FPU or MSA already active, restore full MSA state */
1591 		__kvm_restore_msa(&vcpu->arch);
1592 		vcpu->arch.aux_inuse |= KVM_MIPS_AUX_MSA;
1593 		if (kvm_mips_guest_has_fpu(&vcpu->arch))
1594 			vcpu->arch.aux_inuse |= KVM_MIPS_AUX_FPU;
1595 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE,
1596 			      KVM_TRACE_AUX_FPU_MSA);
1597 		break;
1598 	default:
1599 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_ENABLE, KVM_TRACE_AUX_MSA);
1600 		break;
1601 	}
1602 
1603 	preempt_enable();
1604 }
1605 #endif
1606 
1607 /* Drop FPU & MSA without saving it */
kvm_drop_fpu(struct kvm_vcpu * vcpu)1608 void kvm_drop_fpu(struct kvm_vcpu *vcpu)
1609 {
1610 	preempt_disable();
1611 	if (cpu_has_msa && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) {
1612 		disable_msa();
1613 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_DISCARD, KVM_TRACE_AUX_MSA);
1614 		vcpu->arch.aux_inuse &= ~KVM_MIPS_AUX_MSA;
1615 	}
1616 	if (vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) {
1617 		clear_c0_status(ST0_CU1 | ST0_FR);
1618 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_DISCARD, KVM_TRACE_AUX_FPU);
1619 		vcpu->arch.aux_inuse &= ~KVM_MIPS_AUX_FPU;
1620 	}
1621 	preempt_enable();
1622 }
1623 
1624 /* Save and disable FPU & MSA */
kvm_lose_fpu(struct kvm_vcpu * vcpu)1625 void kvm_lose_fpu(struct kvm_vcpu *vcpu)
1626 {
1627 	/*
1628 	 * With T&E, FPU & MSA get disabled in root context (hardware) when it
1629 	 * is disabled in guest context (software), but the register state in
1630 	 * the hardware may still be in use.
1631 	 * This is why we explicitly re-enable the hardware before saving.
1632 	 */
1633 
1634 	preempt_disable();
1635 	if (cpu_has_msa && vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) {
1636 		if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) {
1637 			set_c0_config5(MIPS_CONF5_MSAEN);
1638 			enable_fpu_hazard();
1639 		}
1640 
1641 		__kvm_save_msa(&vcpu->arch);
1642 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU_MSA);
1643 
1644 		/* Disable MSA & FPU */
1645 		disable_msa();
1646 		if (vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) {
1647 			clear_c0_status(ST0_CU1 | ST0_FR);
1648 			disable_fpu_hazard();
1649 		}
1650 		vcpu->arch.aux_inuse &= ~(KVM_MIPS_AUX_FPU | KVM_MIPS_AUX_MSA);
1651 	} else if (vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU) {
1652 		if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) {
1653 			set_c0_status(ST0_CU1);
1654 			enable_fpu_hazard();
1655 		}
1656 
1657 		__kvm_save_fpu(&vcpu->arch);
1658 		vcpu->arch.aux_inuse &= ~KVM_MIPS_AUX_FPU;
1659 		trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_FPU);
1660 
1661 		/* Disable FPU */
1662 		clear_c0_status(ST0_CU1 | ST0_FR);
1663 		disable_fpu_hazard();
1664 	}
1665 	preempt_enable();
1666 }
1667 
1668 /*
1669  * Step over a specific ctc1 to FCSR and a specific ctcmsa to MSACSR which are
1670  * used to restore guest FCSR/MSACSR state and may trigger a "harmless" FP/MSAFP
1671  * exception if cause bits are set in the value being written.
1672  */
kvm_mips_csr_die_notify(struct notifier_block * self,unsigned long cmd,void * ptr)1673 static int kvm_mips_csr_die_notify(struct notifier_block *self,
1674 				   unsigned long cmd, void *ptr)
1675 {
1676 	struct die_args *args = (struct die_args *)ptr;
1677 	struct pt_regs *regs = args->regs;
1678 	unsigned long pc;
1679 
1680 	/* Only interested in FPE and MSAFPE */
1681 	if (cmd != DIE_FP && cmd != DIE_MSAFP)
1682 		return NOTIFY_DONE;
1683 
1684 	/* Return immediately if guest context isn't active */
1685 	if (!(current->flags & PF_VCPU))
1686 		return NOTIFY_DONE;
1687 
1688 	/* Should never get here from user mode */
1689 	BUG_ON(user_mode(regs));
1690 
1691 	pc = instruction_pointer(regs);
1692 	switch (cmd) {
1693 	case DIE_FP:
1694 		/* match 2nd instruction in __kvm_restore_fcsr */
1695 		if (pc != (unsigned long)&__kvm_restore_fcsr + 4)
1696 			return NOTIFY_DONE;
1697 		break;
1698 	case DIE_MSAFP:
1699 		/* match 2nd/3rd instruction in __kvm_restore_msacsr */
1700 		if (!cpu_has_msa ||
1701 		    pc < (unsigned long)&__kvm_restore_msacsr + 4 ||
1702 		    pc > (unsigned long)&__kvm_restore_msacsr + 8)
1703 			return NOTIFY_DONE;
1704 		break;
1705 	}
1706 
1707 	/* Move PC forward a little and continue executing */
1708 	instruction_pointer(regs) += 4;
1709 
1710 	return NOTIFY_STOP;
1711 }
1712 
1713 static struct notifier_block kvm_mips_csr_die_notifier = {
1714 	.notifier_call = kvm_mips_csr_die_notify,
1715 };
1716 
kvm_mips_init(void)1717 static int __init kvm_mips_init(void)
1718 {
1719 	int ret;
1720 
1721 	if (cpu_has_mmid) {
1722 		pr_warn("KVM does not yet support MMIDs. KVM Disabled\n");
1723 		return -EOPNOTSUPP;
1724 	}
1725 
1726 	ret = kvm_mips_entry_setup();
1727 	if (ret)
1728 		return ret;
1729 
1730 	ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
1731 
1732 	if (ret)
1733 		return ret;
1734 
1735 	register_die_notifier(&kvm_mips_csr_die_notifier);
1736 
1737 	return 0;
1738 }
1739 
kvm_mips_exit(void)1740 static void __exit kvm_mips_exit(void)
1741 {
1742 	kvm_exit();
1743 
1744 	unregister_die_notifier(&kvm_mips_csr_die_notifier);
1745 }
1746 
1747 module_init(kvm_mips_init);
1748 module_exit(kvm_mips_exit);
1749 
1750 EXPORT_TRACEPOINT_SYMBOL(kvm_exit);
1751