1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
5  */
6 
7 #include <linux/types.h>
8 #include <linux/string.h>
9 #include <linux/kvm.h>
10 #include <linux/kvm_host.h>
11 #include <linux/highmem.h>
12 #include <linux/gfp.h>
13 #include <linux/slab.h>
14 #include <linux/hugetlb.h>
15 #include <linux/vmalloc.h>
16 #include <linux/srcu.h>
17 #include <linux/anon_inodes.h>
18 #include <linux/file.h>
19 #include <linux/debugfs.h>
20 
21 #include <asm/kvm_ppc.h>
22 #include <asm/kvm_book3s.h>
23 #include <asm/book3s/64/mmu-hash.h>
24 #include <asm/hvcall.h>
25 #include <asm/synch.h>
26 #include <asm/ppc-opcode.h>
27 #include <asm/cputable.h>
28 #include <asm/pte-walk.h>
29 
30 #include "book3s.h"
31 #include "book3s_hv.h"
32 #include "trace_hv.h"
33 
34 //#define DEBUG_RESIZE_HPT	1
35 
36 #ifdef DEBUG_RESIZE_HPT
37 #define resize_hpt_debug(resize, ...)				\
38 	do {							\
39 		printk(KERN_DEBUG "RESIZE HPT %p: ", resize);	\
40 		printk(__VA_ARGS__);				\
41 	} while (0)
42 #else
43 #define resize_hpt_debug(resize, ...)				\
44 	do { } while (0)
45 #endif
46 
47 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
48 				long pte_index, unsigned long pteh,
49 				unsigned long ptel, unsigned long *pte_idx_ret);
50 
51 struct kvm_resize_hpt {
52 	/* These fields read-only after init */
53 	struct kvm *kvm;
54 	struct work_struct work;
55 	u32 order;
56 
57 	/* These fields protected by kvm->arch.mmu_setup_lock */
58 
59 	/* Possible values and their usage:
60 	 *  <0     an error occurred during allocation,
61 	 *  -EBUSY allocation is in the progress,
62 	 *  0      allocation made successfully.
63 	 */
64 	int error;
65 
66 	/* Private to the work thread, until error != -EBUSY,
67 	 * then protected by kvm->arch.mmu_setup_lock.
68 	 */
69 	struct kvm_hpt_info hpt;
70 };
71 
72 int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
73 {
74 	unsigned long hpt = 0;
75 	int cma = 0;
76 	struct page *page = NULL;
77 	struct revmap_entry *rev;
78 	unsigned long npte;
79 
80 	if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
81 		return -EINVAL;
82 
83 	page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
84 	if (page) {
85 		hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
86 		memset((void *)hpt, 0, (1ul << order));
87 		cma = 1;
88 	}
89 
90 	if (!hpt)
91 		hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
92 				       |__GFP_NOWARN, order - PAGE_SHIFT);
93 
94 	if (!hpt)
95 		return -ENOMEM;
96 
97 	/* HPTEs are 2**4 bytes long */
98 	npte = 1ul << (order - 4);
99 
100 	/* Allocate reverse map array */
101 	rev = vmalloc(array_size(npte, sizeof(struct revmap_entry)));
102 	if (!rev) {
103 		if (cma)
104 			kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
105 		else
106 			free_pages(hpt, order - PAGE_SHIFT);
107 		return -ENOMEM;
108 	}
109 
110 	info->order = order;
111 	info->virt = hpt;
112 	info->cma = cma;
113 	info->rev = rev;
114 
115 	return 0;
116 }
117 
118 void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
119 {
120 	atomic64_set(&kvm->arch.mmio_update, 0);
121 	kvm->arch.hpt = *info;
122 	kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
123 
124 	pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
125 		 info->virt, (long)info->order, kvm->arch.lpid);
126 }
127 
128 int kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
129 {
130 	int err = -EBUSY;
131 	struct kvm_hpt_info info;
132 
133 	mutex_lock(&kvm->arch.mmu_setup_lock);
134 	if (kvm->arch.mmu_ready) {
135 		kvm->arch.mmu_ready = 0;
136 		/* order mmu_ready vs. vcpus_running */
137 		smp_mb();
138 		if (atomic_read(&kvm->arch.vcpus_running)) {
139 			kvm->arch.mmu_ready = 1;
140 			goto out;
141 		}
142 	}
143 	if (kvm_is_radix(kvm)) {
144 		err = kvmppc_switch_mmu_to_hpt(kvm);
145 		if (err)
146 			goto out;
147 	}
148 
149 	if (kvm->arch.hpt.order == order) {
150 		/* We already have a suitable HPT */
151 
152 		/* Set the entire HPT to 0, i.e. invalid HPTEs */
153 		memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
154 		/*
155 		 * Reset all the reverse-mapping chains for all memslots
156 		 */
157 		kvmppc_rmap_reset(kvm);
158 		err = 0;
159 		goto out;
160 	}
161 
162 	if (kvm->arch.hpt.virt) {
163 		kvmppc_free_hpt(&kvm->arch.hpt);
164 		kvmppc_rmap_reset(kvm);
165 	}
166 
167 	err = kvmppc_allocate_hpt(&info, order);
168 	if (err < 0)
169 		goto out;
170 	kvmppc_set_hpt(kvm, &info);
171 
172 out:
173 	if (err == 0)
174 		/* Ensure that each vcpu will flush its TLB on next entry. */
175 		cpumask_setall(&kvm->arch.need_tlb_flush);
176 
177 	mutex_unlock(&kvm->arch.mmu_setup_lock);
178 	return err;
179 }
180 
181 void kvmppc_free_hpt(struct kvm_hpt_info *info)
182 {
183 	vfree(info->rev);
184 	info->rev = NULL;
185 	if (info->cma)
186 		kvm_free_hpt_cma(virt_to_page((void *)info->virt),
187 				 1 << (info->order - PAGE_SHIFT));
188 	else if (info->virt)
189 		free_pages(info->virt, info->order - PAGE_SHIFT);
190 	info->virt = 0;
191 	info->order = 0;
192 }
193 
194 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
195 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
196 {
197 	return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
198 }
199 
200 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
201 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
202 {
203 	return (pgsize == 0x10000) ? 0x1000 : 0;
204 }
205 
206 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
207 		     unsigned long porder)
208 {
209 	unsigned long i;
210 	unsigned long npages;
211 	unsigned long hp_v, hp_r;
212 	unsigned long addr, hash;
213 	unsigned long psize;
214 	unsigned long hp0, hp1;
215 	unsigned long idx_ret;
216 	long ret;
217 	struct kvm *kvm = vcpu->kvm;
218 
219 	psize = 1ul << porder;
220 	npages = memslot->npages >> (porder - PAGE_SHIFT);
221 
222 	/* VRMA can't be > 1TB */
223 	if (npages > 1ul << (40 - porder))
224 		npages = 1ul << (40 - porder);
225 	/* Can't use more than 1 HPTE per HPTEG */
226 	if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
227 		npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
228 
229 	hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
230 		HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
231 	hp1 = hpte1_pgsize_encoding(psize) |
232 		HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
233 
234 	for (i = 0; i < npages; ++i) {
235 		addr = i << porder;
236 		/* can't use hpt_hash since va > 64 bits */
237 		hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
238 			& kvmppc_hpt_mask(&kvm->arch.hpt);
239 		/*
240 		 * We assume that the hash table is empty and no
241 		 * vcpus are using it at this stage.  Since we create
242 		 * at most one HPTE per HPTEG, we just assume entry 7
243 		 * is available and use it.
244 		 */
245 		hash = (hash << 3) + 7;
246 		hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
247 		hp_r = hp1 | addr;
248 		ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
249 						 &idx_ret);
250 		if (ret != H_SUCCESS) {
251 			pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
252 			       addr, ret);
253 			break;
254 		}
255 	}
256 }
257 
258 int kvmppc_mmu_hv_init(void)
259 {
260 	unsigned long nr_lpids;
261 
262 	if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE))
263 		return -EINVAL;
264 
265 	if (cpu_has_feature(CPU_FTR_HVMODE)) {
266 		if (WARN_ON(mfspr(SPRN_LPID) != 0))
267 			return -EINVAL;
268 		nr_lpids = 1UL << mmu_lpid_bits;
269 	} else {
270 		nr_lpids = 1UL << KVM_MAX_NESTED_GUESTS_SHIFT;
271 	}
272 
273 	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
274 		/* POWER7 has 10-bit LPIDs, POWER8 has 12-bit LPIDs */
275 		if (cpu_has_feature(CPU_FTR_ARCH_207S))
276 			WARN_ON(nr_lpids != 1UL << 12);
277 		else
278 			WARN_ON(nr_lpids != 1UL << 10);
279 
280 		/*
281 		 * Reserve the last implemented LPID use in partition
282 		 * switching for POWER7 and POWER8.
283 		 */
284 		nr_lpids -= 1;
285 	}
286 
287 	kvmppc_init_lpid(nr_lpids);
288 
289 	return 0;
290 }
291 
292 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
293 				long pte_index, unsigned long pteh,
294 				unsigned long ptel, unsigned long *pte_idx_ret)
295 {
296 	long ret;
297 
298 	preempt_disable();
299 	ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
300 				kvm->mm->pgd, false, pte_idx_ret);
301 	preempt_enable();
302 	if (ret == H_TOO_HARD) {
303 		/* this can't happen */
304 		pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
305 		ret = H_RESOURCE;	/* or something */
306 	}
307 	return ret;
308 
309 }
310 
311 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
312 							 gva_t eaddr)
313 {
314 	u64 mask;
315 	int i;
316 
317 	for (i = 0; i < vcpu->arch.slb_nr; i++) {
318 		if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
319 			continue;
320 
321 		if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
322 			mask = ESID_MASK_1T;
323 		else
324 			mask = ESID_MASK;
325 
326 		if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
327 			return &vcpu->arch.slb[i];
328 	}
329 	return NULL;
330 }
331 
332 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
333 			unsigned long ea)
334 {
335 	unsigned long ra_mask;
336 
337 	ra_mask = kvmppc_actual_pgsz(v, r) - 1;
338 	return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
339 }
340 
341 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
342 			struct kvmppc_pte *gpte, bool data, bool iswrite)
343 {
344 	struct kvm *kvm = vcpu->kvm;
345 	struct kvmppc_slb *slbe;
346 	unsigned long slb_v;
347 	unsigned long pp, key;
348 	unsigned long v, orig_v, gr;
349 	__be64 *hptep;
350 	long int index;
351 	int virtmode = __kvmppc_get_msr_hv(vcpu) & (data ? MSR_DR : MSR_IR);
352 
353 	if (kvm_is_radix(vcpu->kvm))
354 		return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite);
355 
356 	/* Get SLB entry */
357 	if (virtmode) {
358 		slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
359 		if (!slbe)
360 			return -EINVAL;
361 		slb_v = slbe->origv;
362 	} else {
363 		/* real mode access */
364 		slb_v = vcpu->kvm->arch.vrma_slb_v;
365 	}
366 
367 	preempt_disable();
368 	/* Find the HPTE in the hash table */
369 	index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
370 					 HPTE_V_VALID | HPTE_V_ABSENT);
371 	if (index < 0) {
372 		preempt_enable();
373 		return -ENOENT;
374 	}
375 	hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
376 	v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
377 	if (cpu_has_feature(CPU_FTR_ARCH_300))
378 		v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
379 	gr = kvm->arch.hpt.rev[index].guest_rpte;
380 
381 	unlock_hpte(hptep, orig_v);
382 	preempt_enable();
383 
384 	gpte->eaddr = eaddr;
385 	gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
386 
387 	/* Get PP bits and key for permission check */
388 	pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
389 	key = (__kvmppc_get_msr_hv(vcpu) & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
390 	key &= slb_v;
391 
392 	/* Calculate permissions */
393 	gpte->may_read = hpte_read_permission(pp, key);
394 	gpte->may_write = hpte_write_permission(pp, key);
395 	gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
396 
397 	/* Storage key permission check for POWER7 */
398 	if (data && virtmode) {
399 		int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
400 		if (amrfield & 1)
401 			gpte->may_read = 0;
402 		if (amrfield & 2)
403 			gpte->may_write = 0;
404 	}
405 
406 	/* Get the guest physical address */
407 	gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
408 	return 0;
409 }
410 
411 /*
412  * Quick test for whether an instruction is a load or a store.
413  * If the instruction is a load or a store, then this will indicate
414  * which it is, at least on server processors.  (Embedded processors
415  * have some external PID instructions that don't follow the rule
416  * embodied here.)  If the instruction isn't a load or store, then
417  * this doesn't return anything useful.
418  */
419 static int instruction_is_store(ppc_inst_t instr)
420 {
421 	unsigned int mask;
422 	unsigned int suffix;
423 
424 	mask = 0x10000000;
425 	suffix = ppc_inst_val(instr);
426 	if (ppc_inst_prefixed(instr))
427 		suffix = ppc_inst_suffix(instr);
428 	else if ((suffix & 0xfc000000) == 0x7c000000)
429 		mask = 0x100;		/* major opcode 31 */
430 	return (suffix & mask) != 0;
431 }
432 
433 int kvmppc_hv_emulate_mmio(struct kvm_vcpu *vcpu,
434 			   unsigned long gpa, gva_t ea, int is_store)
435 {
436 	ppc_inst_t last_inst;
437 	bool is_prefixed = !!(kvmppc_get_msr(vcpu) & SRR1_PREFIXED);
438 
439 	/*
440 	 * Fast path - check if the guest physical address corresponds to a
441 	 * device on the FAST_MMIO_BUS, if so we can avoid loading the
442 	 * instruction all together, then we can just handle it and return.
443 	 */
444 	if (is_store) {
445 		int idx, ret;
446 
447 		idx = srcu_read_lock(&vcpu->kvm->srcu);
448 		ret = kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, (gpa_t) gpa, 0,
449 				       NULL);
450 		srcu_read_unlock(&vcpu->kvm->srcu, idx);
451 		if (!ret) {
452 			kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + (is_prefixed ? 8 : 4));
453 			return RESUME_GUEST;
454 		}
455 	}
456 
457 	/*
458 	 * If we fail, we just return to the guest and try executing it again.
459 	 */
460 	if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
461 		EMULATE_DONE)
462 		return RESUME_GUEST;
463 
464 	/*
465 	 * WARNING: We do not know for sure whether the instruction we just
466 	 * read from memory is the same that caused the fault in the first
467 	 * place.
468 	 *
469 	 * If the fault is prefixed but the instruction is not or vice
470 	 * versa, try again so that we don't advance pc the wrong amount.
471 	 */
472 	if (ppc_inst_prefixed(last_inst) != is_prefixed)
473 		return RESUME_GUEST;
474 
475 	/*
476 	 * If the instruction we read is neither an load or a store,
477 	 * then it can't access memory, so we don't need to worry about
478 	 * enforcing access permissions.  So, assuming it is a load or
479 	 * store, we just check that its direction (load or store) is
480 	 * consistent with the original fault, since that's what we
481 	 * checked the access permissions against.  If there is a mismatch
482 	 * we just return and retry the instruction.
483 	 */
484 
485 	if (instruction_is_store(last_inst) != !!is_store)
486 		return RESUME_GUEST;
487 
488 	/*
489 	 * Emulated accesses are emulated by looking at the hash for
490 	 * translation once, then performing the access later. The
491 	 * translation could be invalidated in the meantime in which
492 	 * point performing the subsequent memory access on the old
493 	 * physical address could possibly be a security hole for the
494 	 * guest (but not the host).
495 	 *
496 	 * This is less of an issue for MMIO stores since they aren't
497 	 * globally visible. It could be an issue for MMIO loads to
498 	 * a certain extent but we'll ignore it for now.
499 	 */
500 
501 	vcpu->arch.paddr_accessed = gpa;
502 	vcpu->arch.vaddr_accessed = ea;
503 	return kvmppc_emulate_mmio(vcpu);
504 }
505 
506 int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu,
507 				unsigned long ea, unsigned long dsisr)
508 {
509 	struct kvm *kvm = vcpu->kvm;
510 	unsigned long hpte[3], r;
511 	unsigned long hnow_v, hnow_r;
512 	__be64 *hptep;
513 	unsigned long mmu_seq, psize, pte_size;
514 	unsigned long gpa_base, gfn_base;
515 	unsigned long gpa, gfn, hva, pfn, hpa;
516 	struct kvm_memory_slot *memslot;
517 	unsigned long *rmap;
518 	struct revmap_entry *rev;
519 	struct page *page;
520 	long index, ret;
521 	bool is_ci;
522 	bool writing, write_ok;
523 	unsigned int shift;
524 	unsigned long rcbits;
525 	long mmio_update;
526 	pte_t pte, *ptep;
527 
528 	if (kvm_is_radix(kvm))
529 		return kvmppc_book3s_radix_page_fault(vcpu, ea, dsisr);
530 
531 	/*
532 	 * Real-mode code has already searched the HPT and found the
533 	 * entry we're interested in.  Lock the entry and check that
534 	 * it hasn't changed.  If it has, just return and re-execute the
535 	 * instruction.
536 	 */
537 	if (ea != vcpu->arch.pgfault_addr)
538 		return RESUME_GUEST;
539 
540 	if (vcpu->arch.pgfault_cache) {
541 		mmio_update = atomic64_read(&kvm->arch.mmio_update);
542 		if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
543 			r = vcpu->arch.pgfault_cache->rpte;
544 			psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0],
545 						   r);
546 			gpa_base = r & HPTE_R_RPN & ~(psize - 1);
547 			gfn_base = gpa_base >> PAGE_SHIFT;
548 			gpa = gpa_base | (ea & (psize - 1));
549 			return kvmppc_hv_emulate_mmio(vcpu, gpa, ea,
550 						dsisr & DSISR_ISSTORE);
551 		}
552 	}
553 	index = vcpu->arch.pgfault_index;
554 	hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
555 	rev = &kvm->arch.hpt.rev[index];
556 	preempt_disable();
557 	while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
558 		cpu_relax();
559 	hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
560 	hpte[1] = be64_to_cpu(hptep[1]);
561 	hpte[2] = r = rev->guest_rpte;
562 	unlock_hpte(hptep, hpte[0]);
563 	preempt_enable();
564 
565 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
566 		hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
567 		hpte[1] = hpte_new_to_old_r(hpte[1]);
568 	}
569 	if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
570 	    hpte[1] != vcpu->arch.pgfault_hpte[1])
571 		return RESUME_GUEST;
572 
573 	/* Translate the logical address and get the page */
574 	psize = kvmppc_actual_pgsz(hpte[0], r);
575 	gpa_base = r & HPTE_R_RPN & ~(psize - 1);
576 	gfn_base = gpa_base >> PAGE_SHIFT;
577 	gpa = gpa_base | (ea & (psize - 1));
578 	gfn = gpa >> PAGE_SHIFT;
579 	memslot = gfn_to_memslot(kvm, gfn);
580 
581 	trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
582 
583 	/* No memslot means it's an emulated MMIO region */
584 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
585 		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea,
586 					      dsisr & DSISR_ISSTORE);
587 
588 	/*
589 	 * This should never happen, because of the slot_is_aligned()
590 	 * check in kvmppc_do_h_enter().
591 	 */
592 	if (gfn_base < memslot->base_gfn)
593 		return -EFAULT;
594 
595 	/* used to check for invalidations in progress */
596 	mmu_seq = kvm->mmu_invalidate_seq;
597 	smp_rmb();
598 
599 	ret = -EFAULT;
600 	page = NULL;
601 	writing = (dsisr & DSISR_ISSTORE) != 0;
602 	/* If writing != 0, then the HPTE must allow writing, if we get here */
603 	write_ok = writing;
604 	hva = gfn_to_hva_memslot(memslot, gfn);
605 
606 	/*
607 	 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
608 	 * do it with !atomic && !async, which is how we call it.
609 	 * We always ask for write permission since the common case
610 	 * is that the page is writable.
611 	 */
612 	if (get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
613 		write_ok = true;
614 	} else {
615 		/* Call KVM generic code to do the slow-path check */
616 		pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
617 					   writing, &write_ok, NULL);
618 		if (is_error_noslot_pfn(pfn))
619 			return -EFAULT;
620 		page = NULL;
621 		if (pfn_valid(pfn)) {
622 			page = pfn_to_page(pfn);
623 			if (PageReserved(page))
624 				page = NULL;
625 		}
626 	}
627 
628 	/*
629 	 * Read the PTE from the process' radix tree and use that
630 	 * so we get the shift and attribute bits.
631 	 */
632 	spin_lock(&kvm->mmu_lock);
633 	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
634 	pte = __pte(0);
635 	if (ptep)
636 		pte = READ_ONCE(*ptep);
637 	spin_unlock(&kvm->mmu_lock);
638 	/*
639 	 * If the PTE disappeared temporarily due to a THP
640 	 * collapse, just return and let the guest try again.
641 	 */
642 	if (!pte_present(pte)) {
643 		if (page)
644 			put_page(page);
645 		return RESUME_GUEST;
646 	}
647 	hpa = pte_pfn(pte) << PAGE_SHIFT;
648 	pte_size = PAGE_SIZE;
649 	if (shift)
650 		pte_size = 1ul << shift;
651 	is_ci = pte_ci(pte);
652 
653 	if (psize > pte_size)
654 		goto out_put;
655 	if (pte_size > psize)
656 		hpa |= hva & (pte_size - psize);
657 
658 	/* Check WIMG vs. the actual page we're accessing */
659 	if (!hpte_cache_flags_ok(r, is_ci)) {
660 		if (is_ci)
661 			goto out_put;
662 		/*
663 		 * Allow guest to map emulated device memory as
664 		 * uncacheable, but actually make it cacheable.
665 		 */
666 		r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
667 	}
668 
669 	/*
670 	 * Set the HPTE to point to hpa.
671 	 * Since the hpa is at PAGE_SIZE granularity, make sure we
672 	 * don't mask out lower-order bits if psize < PAGE_SIZE.
673 	 */
674 	if (psize < PAGE_SIZE)
675 		psize = PAGE_SIZE;
676 	r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) | hpa;
677 	if (hpte_is_writable(r) && !write_ok)
678 		r = hpte_make_readonly(r);
679 	ret = RESUME_GUEST;
680 	preempt_disable();
681 	while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
682 		cpu_relax();
683 	hnow_v = be64_to_cpu(hptep[0]);
684 	hnow_r = be64_to_cpu(hptep[1]);
685 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
686 		hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
687 		hnow_r = hpte_new_to_old_r(hnow_r);
688 	}
689 
690 	/*
691 	 * If the HPT is being resized, don't update the HPTE,
692 	 * instead let the guest retry after the resize operation is complete.
693 	 * The synchronization for mmu_ready test vs. set is provided
694 	 * by the HPTE lock.
695 	 */
696 	if (!kvm->arch.mmu_ready)
697 		goto out_unlock;
698 
699 	if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
700 	    rev->guest_rpte != hpte[2])
701 		/* HPTE has been changed under us; let the guest retry */
702 		goto out_unlock;
703 	hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
704 
705 	/* Always put the HPTE in the rmap chain for the page base address */
706 	rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
707 	lock_rmap(rmap);
708 
709 	/* Check if we might have been invalidated; let the guest retry if so */
710 	ret = RESUME_GUEST;
711 	if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) {
712 		unlock_rmap(rmap);
713 		goto out_unlock;
714 	}
715 
716 	/* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
717 	rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
718 	r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
719 
720 	if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
721 		/* HPTE was previously valid, so we need to invalidate it */
722 		unlock_rmap(rmap);
723 		hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
724 		kvmppc_invalidate_hpte(kvm, hptep, index);
725 		/* don't lose previous R and C bits */
726 		r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
727 	} else {
728 		kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
729 	}
730 
731 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
732 		r = hpte_old_to_new_r(hpte[0], r);
733 		hpte[0] = hpte_old_to_new_v(hpte[0]);
734 	}
735 	hptep[1] = cpu_to_be64(r);
736 	eieio();
737 	__unlock_hpte(hptep, hpte[0]);
738 	asm volatile("ptesync" : : : "memory");
739 	preempt_enable();
740 	if (page && hpte_is_writable(r))
741 		set_page_dirty_lock(page);
742 
743  out_put:
744 	trace_kvm_page_fault_exit(vcpu, hpte, ret);
745 
746 	if (page)
747 		put_page(page);
748 	return ret;
749 
750  out_unlock:
751 	__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
752 	preempt_enable();
753 	goto out_put;
754 }
755 
756 void kvmppc_rmap_reset(struct kvm *kvm)
757 {
758 	struct kvm_memslots *slots;
759 	struct kvm_memory_slot *memslot;
760 	int srcu_idx, bkt;
761 
762 	srcu_idx = srcu_read_lock(&kvm->srcu);
763 	slots = kvm_memslots(kvm);
764 	kvm_for_each_memslot(memslot, bkt, slots) {
765 		/* Mutual exclusion with kvm_unmap_hva_range etc. */
766 		spin_lock(&kvm->mmu_lock);
767 		/*
768 		 * This assumes it is acceptable to lose reference and
769 		 * change bits across a reset.
770 		 */
771 		memset(memslot->arch.rmap, 0,
772 		       memslot->npages * sizeof(*memslot->arch.rmap));
773 		spin_unlock(&kvm->mmu_lock);
774 	}
775 	srcu_read_unlock(&kvm->srcu, srcu_idx);
776 }
777 
778 /* Must be called with both HPTE and rmap locked */
779 static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
780 			      struct kvm_memory_slot *memslot,
781 			      unsigned long *rmapp, unsigned long gfn)
782 {
783 	__be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
784 	struct revmap_entry *rev = kvm->arch.hpt.rev;
785 	unsigned long j, h;
786 	unsigned long ptel, psize, rcbits;
787 
788 	j = rev[i].forw;
789 	if (j == i) {
790 		/* chain is now empty */
791 		*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
792 	} else {
793 		/* remove i from chain */
794 		h = rev[i].back;
795 		rev[h].forw = j;
796 		rev[j].back = h;
797 		rev[i].forw = rev[i].back = i;
798 		*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
799 	}
800 
801 	/* Now check and modify the HPTE */
802 	ptel = rev[i].guest_rpte;
803 	psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel);
804 	if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
805 	    hpte_rpn(ptel, psize) == gfn) {
806 		hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
807 		kvmppc_invalidate_hpte(kvm, hptep, i);
808 		hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
809 		/* Harvest R and C */
810 		rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
811 		*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
812 		if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap)
813 			kvmppc_update_dirty_map(memslot, gfn, psize);
814 		if (rcbits & ~rev[i].guest_rpte) {
815 			rev[i].guest_rpte = ptel | rcbits;
816 			note_hpte_modification(kvm, &rev[i]);
817 		}
818 	}
819 }
820 
821 static void kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
822 			    unsigned long gfn)
823 {
824 	unsigned long i;
825 	__be64 *hptep;
826 	unsigned long *rmapp;
827 
828 	rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
829 	for (;;) {
830 		lock_rmap(rmapp);
831 		if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
832 			unlock_rmap(rmapp);
833 			break;
834 		}
835 
836 		/*
837 		 * To avoid an ABBA deadlock with the HPTE lock bit,
838 		 * we can't spin on the HPTE lock while holding the
839 		 * rmap chain lock.
840 		 */
841 		i = *rmapp & KVMPPC_RMAP_INDEX;
842 		hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
843 		if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
844 			/* unlock rmap before spinning on the HPTE lock */
845 			unlock_rmap(rmapp);
846 			while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
847 				cpu_relax();
848 			continue;
849 		}
850 
851 		kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn);
852 		unlock_rmap(rmapp);
853 		__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
854 	}
855 }
856 
857 bool kvm_unmap_gfn_range_hv(struct kvm *kvm, struct kvm_gfn_range *range)
858 {
859 	gfn_t gfn;
860 
861 	if (kvm_is_radix(kvm)) {
862 		for (gfn = range->start; gfn < range->end; gfn++)
863 			kvm_unmap_radix(kvm, range->slot, gfn);
864 	} else {
865 		for (gfn = range->start; gfn < range->end; gfn++)
866 			kvm_unmap_rmapp(kvm, range->slot, gfn);
867 	}
868 
869 	return false;
870 }
871 
872 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
873 				  struct kvm_memory_slot *memslot)
874 {
875 	unsigned long gfn;
876 	unsigned long n;
877 	unsigned long *rmapp;
878 
879 	gfn = memslot->base_gfn;
880 	rmapp = memslot->arch.rmap;
881 	if (kvm_is_radix(kvm)) {
882 		kvmppc_radix_flush_memslot(kvm, memslot);
883 		return;
884 	}
885 
886 	for (n = memslot->npages; n; --n, ++gfn) {
887 		/*
888 		 * Testing the present bit without locking is OK because
889 		 * the memslot has been marked invalid already, and hence
890 		 * no new HPTEs referencing this page can be created,
891 		 * thus the present bit can't go from 0 to 1.
892 		 */
893 		if (*rmapp & KVMPPC_RMAP_PRESENT)
894 			kvm_unmap_rmapp(kvm, memslot, gfn);
895 		++rmapp;
896 	}
897 }
898 
899 static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
900 			  unsigned long gfn)
901 {
902 	struct revmap_entry *rev = kvm->arch.hpt.rev;
903 	unsigned long head, i, j;
904 	__be64 *hptep;
905 	bool ret = false;
906 	unsigned long *rmapp;
907 
908 	rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
909  retry:
910 	lock_rmap(rmapp);
911 	if (*rmapp & KVMPPC_RMAP_REFERENCED) {
912 		*rmapp &= ~KVMPPC_RMAP_REFERENCED;
913 		ret = true;
914 	}
915 	if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
916 		unlock_rmap(rmapp);
917 		return ret;
918 	}
919 
920 	i = head = *rmapp & KVMPPC_RMAP_INDEX;
921 	do {
922 		hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
923 		j = rev[i].forw;
924 
925 		/* If this HPTE isn't referenced, ignore it */
926 		if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
927 			continue;
928 
929 		if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
930 			/* unlock rmap before spinning on the HPTE lock */
931 			unlock_rmap(rmapp);
932 			while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
933 				cpu_relax();
934 			goto retry;
935 		}
936 
937 		/* Now check and modify the HPTE */
938 		if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
939 		    (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
940 			kvmppc_clear_ref_hpte(kvm, hptep, i);
941 			if (!(rev[i].guest_rpte & HPTE_R_R)) {
942 				rev[i].guest_rpte |= HPTE_R_R;
943 				note_hpte_modification(kvm, &rev[i]);
944 			}
945 			ret = true;
946 		}
947 		__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
948 	} while ((i = j) != head);
949 
950 	unlock_rmap(rmapp);
951 	return ret;
952 }
953 
954 bool kvm_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
955 {
956 	gfn_t gfn;
957 	bool ret = false;
958 
959 	if (kvm_is_radix(kvm)) {
960 		for (gfn = range->start; gfn < range->end; gfn++)
961 			ret |= kvm_age_radix(kvm, range->slot, gfn);
962 	} else {
963 		for (gfn = range->start; gfn < range->end; gfn++)
964 			ret |= kvm_age_rmapp(kvm, range->slot, gfn);
965 	}
966 
967 	return ret;
968 }
969 
970 static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
971 			       unsigned long gfn)
972 {
973 	struct revmap_entry *rev = kvm->arch.hpt.rev;
974 	unsigned long head, i, j;
975 	unsigned long *hp;
976 	bool ret = true;
977 	unsigned long *rmapp;
978 
979 	rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
980 	if (*rmapp & KVMPPC_RMAP_REFERENCED)
981 		return true;
982 
983 	lock_rmap(rmapp);
984 	if (*rmapp & KVMPPC_RMAP_REFERENCED)
985 		goto out;
986 
987 	if (*rmapp & KVMPPC_RMAP_PRESENT) {
988 		i = head = *rmapp & KVMPPC_RMAP_INDEX;
989 		do {
990 			hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
991 			j = rev[i].forw;
992 			if (be64_to_cpu(hp[1]) & HPTE_R_R)
993 				goto out;
994 		} while ((i = j) != head);
995 	}
996 	ret = false;
997 
998  out:
999 	unlock_rmap(rmapp);
1000 	return ret;
1001 }
1002 
1003 bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
1004 {
1005 	WARN_ON(range->start + 1 != range->end);
1006 
1007 	if (kvm_is_radix(kvm))
1008 		return kvm_test_age_radix(kvm, range->slot, range->start);
1009 	else
1010 		return kvm_test_age_rmapp(kvm, range->slot, range->start);
1011 }
1012 
1013 bool kvm_set_spte_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range)
1014 {
1015 	WARN_ON(range->start + 1 != range->end);
1016 
1017 	if (kvm_is_radix(kvm))
1018 		kvm_unmap_radix(kvm, range->slot, range->start);
1019 	else
1020 		kvm_unmap_rmapp(kvm, range->slot, range->start);
1021 
1022 	return false;
1023 }
1024 
1025 static int vcpus_running(struct kvm *kvm)
1026 {
1027 	return atomic_read(&kvm->arch.vcpus_running) != 0;
1028 }
1029 
1030 /*
1031  * Returns the number of system pages that are dirty.
1032  * This can be more than 1 if we find a huge-page HPTE.
1033  */
1034 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1035 {
1036 	struct revmap_entry *rev = kvm->arch.hpt.rev;
1037 	unsigned long head, i, j;
1038 	unsigned long n;
1039 	unsigned long v, r;
1040 	__be64 *hptep;
1041 	int npages_dirty = 0;
1042 
1043  retry:
1044 	lock_rmap(rmapp);
1045 	if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1046 		unlock_rmap(rmapp);
1047 		return npages_dirty;
1048 	}
1049 
1050 	i = head = *rmapp & KVMPPC_RMAP_INDEX;
1051 	do {
1052 		unsigned long hptep1;
1053 		hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
1054 		j = rev[i].forw;
1055 
1056 		/*
1057 		 * Checking the C (changed) bit here is racy since there
1058 		 * is no guarantee about when the hardware writes it back.
1059 		 * If the HPTE is not writable then it is stable since the
1060 		 * page can't be written to, and we would have done a tlbie
1061 		 * (which forces the hardware to complete any writeback)
1062 		 * when making the HPTE read-only.
1063 		 * If vcpus are running then this call is racy anyway
1064 		 * since the page could get dirtied subsequently, so we
1065 		 * expect there to be a further call which would pick up
1066 		 * any delayed C bit writeback.
1067 		 * Otherwise we need to do the tlbie even if C==0 in
1068 		 * order to pick up any delayed writeback of C.
1069 		 */
1070 		hptep1 = be64_to_cpu(hptep[1]);
1071 		if (!(hptep1 & HPTE_R_C) &&
1072 		    (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1073 			continue;
1074 
1075 		if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1076 			/* unlock rmap before spinning on the HPTE lock */
1077 			unlock_rmap(rmapp);
1078 			while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1079 				cpu_relax();
1080 			goto retry;
1081 		}
1082 
1083 		/* Now check and modify the HPTE */
1084 		if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
1085 			__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
1086 			continue;
1087 		}
1088 
1089 		/* need to make it temporarily absent so C is stable */
1090 		hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1091 		kvmppc_invalidate_hpte(kvm, hptep, i);
1092 		v = be64_to_cpu(hptep[0]);
1093 		r = be64_to_cpu(hptep[1]);
1094 		if (r & HPTE_R_C) {
1095 			hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1096 			if (!(rev[i].guest_rpte & HPTE_R_C)) {
1097 				rev[i].guest_rpte |= HPTE_R_C;
1098 				note_hpte_modification(kvm, &rev[i]);
1099 			}
1100 			n = kvmppc_actual_pgsz(v, r);
1101 			n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1102 			if (n > npages_dirty)
1103 				npages_dirty = n;
1104 			eieio();
1105 		}
1106 		v &= ~HPTE_V_ABSENT;
1107 		v |= HPTE_V_VALID;
1108 		__unlock_hpte(hptep, v);
1109 	} while ((i = j) != head);
1110 
1111 	unlock_rmap(rmapp);
1112 	return npages_dirty;
1113 }
1114 
1115 void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1116 			      struct kvm_memory_slot *memslot,
1117 			      unsigned long *map)
1118 {
1119 	unsigned long gfn;
1120 
1121 	if (!vpa->dirty || !vpa->pinned_addr)
1122 		return;
1123 	gfn = vpa->gpa >> PAGE_SHIFT;
1124 	if (gfn < memslot->base_gfn ||
1125 	    gfn >= memslot->base_gfn + memslot->npages)
1126 		return;
1127 
1128 	vpa->dirty = false;
1129 	if (map)
1130 		__set_bit_le(gfn - memslot->base_gfn, map);
1131 }
1132 
1133 long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
1134 			struct kvm_memory_slot *memslot, unsigned long *map)
1135 {
1136 	unsigned long i;
1137 	unsigned long *rmapp;
1138 
1139 	preempt_disable();
1140 	rmapp = memslot->arch.rmap;
1141 	for (i = 0; i < memslot->npages; ++i) {
1142 		int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1143 		/*
1144 		 * Note that if npages > 0 then i must be a multiple of npages,
1145 		 * since we always put huge-page HPTEs in the rmap chain
1146 		 * corresponding to their page base address.
1147 		 */
1148 		if (npages)
1149 			set_dirty_bits(map, i, npages);
1150 		++rmapp;
1151 	}
1152 	preempt_enable();
1153 	return 0;
1154 }
1155 
1156 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1157 			    unsigned long *nb_ret)
1158 {
1159 	struct kvm_memory_slot *memslot;
1160 	unsigned long gfn = gpa >> PAGE_SHIFT;
1161 	struct page *page, *pages[1];
1162 	int npages;
1163 	unsigned long hva, offset;
1164 	int srcu_idx;
1165 
1166 	srcu_idx = srcu_read_lock(&kvm->srcu);
1167 	memslot = gfn_to_memslot(kvm, gfn);
1168 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1169 		goto err;
1170 	hva = gfn_to_hva_memslot(memslot, gfn);
1171 	npages = get_user_pages_fast(hva, 1, FOLL_WRITE, pages);
1172 	if (npages < 1)
1173 		goto err;
1174 	page = pages[0];
1175 	srcu_read_unlock(&kvm->srcu, srcu_idx);
1176 
1177 	offset = gpa & (PAGE_SIZE - 1);
1178 	if (nb_ret)
1179 		*nb_ret = PAGE_SIZE - offset;
1180 	return page_address(page) + offset;
1181 
1182  err:
1183 	srcu_read_unlock(&kvm->srcu, srcu_idx);
1184 	return NULL;
1185 }
1186 
1187 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1188 			     bool dirty)
1189 {
1190 	struct page *page = virt_to_page(va);
1191 	struct kvm_memory_slot *memslot;
1192 	unsigned long gfn;
1193 	int srcu_idx;
1194 
1195 	put_page(page);
1196 
1197 	if (!dirty)
1198 		return;
1199 
1200 	/* We need to mark this page dirty in the memslot dirty_bitmap, if any */
1201 	gfn = gpa >> PAGE_SHIFT;
1202 	srcu_idx = srcu_read_lock(&kvm->srcu);
1203 	memslot = gfn_to_memslot(kvm, gfn);
1204 	if (memslot && memslot->dirty_bitmap)
1205 		set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap);
1206 	srcu_read_unlock(&kvm->srcu, srcu_idx);
1207 }
1208 
1209 /*
1210  * HPT resizing
1211  */
1212 static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
1213 {
1214 	int rc;
1215 
1216 	rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
1217 	if (rc < 0)
1218 		return rc;
1219 
1220 	resize_hpt_debug(resize, "%s(): HPT @ 0x%lx\n", __func__,
1221 			 resize->hpt.virt);
1222 
1223 	return 0;
1224 }
1225 
1226 static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
1227 					    unsigned long idx)
1228 {
1229 	struct kvm *kvm = resize->kvm;
1230 	struct kvm_hpt_info *old = &kvm->arch.hpt;
1231 	struct kvm_hpt_info *new = &resize->hpt;
1232 	unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
1233 	unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
1234 	__be64 *hptep, *new_hptep;
1235 	unsigned long vpte, rpte, guest_rpte;
1236 	int ret;
1237 	struct revmap_entry *rev;
1238 	unsigned long apsize, avpn, pteg, hash;
1239 	unsigned long new_idx, new_pteg, replace_vpte;
1240 	int pshift;
1241 
1242 	hptep = (__be64 *)(old->virt + (idx << 4));
1243 
1244 	/* Guest is stopped, so new HPTEs can't be added or faulted
1245 	 * in, only unmapped or altered by host actions.  So, it's
1246 	 * safe to check this before we take the HPTE lock */
1247 	vpte = be64_to_cpu(hptep[0]);
1248 	if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1249 		return 0; /* nothing to do */
1250 
1251 	while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
1252 		cpu_relax();
1253 
1254 	vpte = be64_to_cpu(hptep[0]);
1255 
1256 	ret = 0;
1257 	if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1258 		/* Nothing to do */
1259 		goto out;
1260 
1261 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1262 		rpte = be64_to_cpu(hptep[1]);
1263 		vpte = hpte_new_to_old_v(vpte, rpte);
1264 	}
1265 
1266 	/* Unmap */
1267 	rev = &old->rev[idx];
1268 	guest_rpte = rev->guest_rpte;
1269 
1270 	ret = -EIO;
1271 	apsize = kvmppc_actual_pgsz(vpte, guest_rpte);
1272 	if (!apsize)
1273 		goto out;
1274 
1275 	if (vpte & HPTE_V_VALID) {
1276 		unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1277 		int srcu_idx = srcu_read_lock(&kvm->srcu);
1278 		struct kvm_memory_slot *memslot =
1279 			__gfn_to_memslot(kvm_memslots(kvm), gfn);
1280 
1281 		if (memslot) {
1282 			unsigned long *rmapp;
1283 			rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1284 
1285 			lock_rmap(rmapp);
1286 			kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn);
1287 			unlock_rmap(rmapp);
1288 		}
1289 
1290 		srcu_read_unlock(&kvm->srcu, srcu_idx);
1291 	}
1292 
1293 	/* Reload PTE after unmap */
1294 	vpte = be64_to_cpu(hptep[0]);
1295 	BUG_ON(vpte & HPTE_V_VALID);
1296 	BUG_ON(!(vpte & HPTE_V_ABSENT));
1297 
1298 	ret = 0;
1299 	if (!(vpte & HPTE_V_BOLTED))
1300 		goto out;
1301 
1302 	rpte = be64_to_cpu(hptep[1]);
1303 
1304 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1305 		vpte = hpte_new_to_old_v(vpte, rpte);
1306 		rpte = hpte_new_to_old_r(rpte);
1307 	}
1308 
1309 	pshift = kvmppc_hpte_base_page_shift(vpte, rpte);
1310 	avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23);
1311 	pteg = idx / HPTES_PER_GROUP;
1312 	if (vpte & HPTE_V_SECONDARY)
1313 		pteg = ~pteg;
1314 
1315 	if (!(vpte & HPTE_V_1TB_SEG)) {
1316 		unsigned long offset, vsid;
1317 
1318 		/* We only have 28 - 23 bits of offset in avpn */
1319 		offset = (avpn & 0x1f) << 23;
1320 		vsid = avpn >> 5;
1321 		/* We can find more bits from the pteg value */
1322 		if (pshift < 23)
1323 			offset |= ((vsid ^ pteg) & old_hash_mask) << pshift;
1324 
1325 		hash = vsid ^ (offset >> pshift);
1326 	} else {
1327 		unsigned long offset, vsid;
1328 
1329 		/* We only have 40 - 23 bits of seg_off in avpn */
1330 		offset = (avpn & 0x1ffff) << 23;
1331 		vsid = avpn >> 17;
1332 		if (pshift < 23)
1333 			offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift;
1334 
1335 		hash = vsid ^ (vsid << 25) ^ (offset >> pshift);
1336 	}
1337 
1338 	new_pteg = hash & new_hash_mask;
1339 	if (vpte & HPTE_V_SECONDARY)
1340 		new_pteg = ~hash & new_hash_mask;
1341 
1342 	new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1343 	new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1344 
1345 	replace_vpte = be64_to_cpu(new_hptep[0]);
1346 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1347 		unsigned long replace_rpte = be64_to_cpu(new_hptep[1]);
1348 		replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte);
1349 	}
1350 
1351 	if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1352 		BUG_ON(new->order >= old->order);
1353 
1354 		if (replace_vpte & HPTE_V_BOLTED) {
1355 			if (vpte & HPTE_V_BOLTED)
1356 				/* Bolted collision, nothing we can do */
1357 				ret = -ENOSPC;
1358 			/* Discard the new HPTE */
1359 			goto out;
1360 		}
1361 
1362 		/* Discard the previous HPTE */
1363 	}
1364 
1365 	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1366 		rpte = hpte_old_to_new_r(vpte, rpte);
1367 		vpte = hpte_old_to_new_v(vpte);
1368 	}
1369 
1370 	new_hptep[1] = cpu_to_be64(rpte);
1371 	new->rev[new_idx].guest_rpte = guest_rpte;
1372 	/* No need for a barrier, since new HPT isn't active */
1373 	new_hptep[0] = cpu_to_be64(vpte);
1374 	unlock_hpte(new_hptep, vpte);
1375 
1376 out:
1377 	unlock_hpte(hptep, vpte);
1378 	return ret;
1379 }
1380 
1381 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1382 {
1383 	struct kvm *kvm = resize->kvm;
1384 	unsigned  long i;
1385 	int rc;
1386 
1387 	for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1388 		rc = resize_hpt_rehash_hpte(resize, i);
1389 		if (rc != 0)
1390 			return rc;
1391 	}
1392 
1393 	return 0;
1394 }
1395 
1396 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1397 {
1398 	struct kvm *kvm = resize->kvm;
1399 	struct kvm_hpt_info hpt_tmp;
1400 
1401 	/* Exchange the pending tables in the resize structure with
1402 	 * the active tables */
1403 
1404 	resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1405 
1406 	spin_lock(&kvm->mmu_lock);
1407 	asm volatile("ptesync" : : : "memory");
1408 
1409 	hpt_tmp = kvm->arch.hpt;
1410 	kvmppc_set_hpt(kvm, &resize->hpt);
1411 	resize->hpt = hpt_tmp;
1412 
1413 	spin_unlock(&kvm->mmu_lock);
1414 
1415 	synchronize_srcu_expedited(&kvm->srcu);
1416 
1417 	if (cpu_has_feature(CPU_FTR_ARCH_300))
1418 		kvmppc_setup_partition_table(kvm);
1419 
1420 	resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1421 }
1422 
1423 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1424 {
1425 	if (WARN_ON(!mutex_is_locked(&kvm->arch.mmu_setup_lock)))
1426 		return;
1427 
1428 	if (!resize)
1429 		return;
1430 
1431 	if (resize->error != -EBUSY) {
1432 		if (resize->hpt.virt)
1433 			kvmppc_free_hpt(&resize->hpt);
1434 		kfree(resize);
1435 	}
1436 
1437 	if (kvm->arch.resize_hpt == resize)
1438 		kvm->arch.resize_hpt = NULL;
1439 }
1440 
1441 static void resize_hpt_prepare_work(struct work_struct *work)
1442 {
1443 	struct kvm_resize_hpt *resize = container_of(work,
1444 						     struct kvm_resize_hpt,
1445 						     work);
1446 	struct kvm *kvm = resize->kvm;
1447 	int err = 0;
1448 
1449 	if (WARN_ON(resize->error != -EBUSY))
1450 		return;
1451 
1452 	mutex_lock(&kvm->arch.mmu_setup_lock);
1453 
1454 	/* Request is still current? */
1455 	if (kvm->arch.resize_hpt == resize) {
1456 		/* We may request large allocations here:
1457 		 * do not sleep with kvm->arch.mmu_setup_lock held for a while.
1458 		 */
1459 		mutex_unlock(&kvm->arch.mmu_setup_lock);
1460 
1461 		resize_hpt_debug(resize, "%s(): order = %d\n", __func__,
1462 				 resize->order);
1463 
1464 		err = resize_hpt_allocate(resize);
1465 
1466 		/* We have strict assumption about -EBUSY
1467 		 * when preparing for HPT resize.
1468 		 */
1469 		if (WARN_ON(err == -EBUSY))
1470 			err = -EINPROGRESS;
1471 
1472 		mutex_lock(&kvm->arch.mmu_setup_lock);
1473 		/* It is possible that kvm->arch.resize_hpt != resize
1474 		 * after we grab kvm->arch.mmu_setup_lock again.
1475 		 */
1476 	}
1477 
1478 	resize->error = err;
1479 
1480 	if (kvm->arch.resize_hpt != resize)
1481 		resize_hpt_release(kvm, resize);
1482 
1483 	mutex_unlock(&kvm->arch.mmu_setup_lock);
1484 }
1485 
1486 int kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1487 				    struct kvm_ppc_resize_hpt *rhpt)
1488 {
1489 	unsigned long flags = rhpt->flags;
1490 	unsigned long shift = rhpt->shift;
1491 	struct kvm_resize_hpt *resize;
1492 	int ret;
1493 
1494 	if (flags != 0 || kvm_is_radix(kvm))
1495 		return -EINVAL;
1496 
1497 	if (shift && ((shift < 18) || (shift > 46)))
1498 		return -EINVAL;
1499 
1500 	mutex_lock(&kvm->arch.mmu_setup_lock);
1501 
1502 	resize = kvm->arch.resize_hpt;
1503 
1504 	if (resize) {
1505 		if (resize->order == shift) {
1506 			/* Suitable resize in progress? */
1507 			ret = resize->error;
1508 			if (ret == -EBUSY)
1509 				ret = 100; /* estimated time in ms */
1510 			else if (ret)
1511 				resize_hpt_release(kvm, resize);
1512 
1513 			goto out;
1514 		}
1515 
1516 		/* not suitable, cancel it */
1517 		resize_hpt_release(kvm, resize);
1518 	}
1519 
1520 	ret = 0;
1521 	if (!shift)
1522 		goto out; /* nothing to do */
1523 
1524 	/* start new resize */
1525 
1526 	resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1527 	if (!resize) {
1528 		ret = -ENOMEM;
1529 		goto out;
1530 	}
1531 
1532 	resize->error = -EBUSY;
1533 	resize->order = shift;
1534 	resize->kvm = kvm;
1535 	INIT_WORK(&resize->work, resize_hpt_prepare_work);
1536 	kvm->arch.resize_hpt = resize;
1537 
1538 	schedule_work(&resize->work);
1539 
1540 	ret = 100; /* estimated time in ms */
1541 
1542 out:
1543 	mutex_unlock(&kvm->arch.mmu_setup_lock);
1544 	return ret;
1545 }
1546 
1547 static void resize_hpt_boot_vcpu(void *opaque)
1548 {
1549 	/* Nothing to do, just force a KVM exit */
1550 }
1551 
1552 int kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1553 				   struct kvm_ppc_resize_hpt *rhpt)
1554 {
1555 	unsigned long flags = rhpt->flags;
1556 	unsigned long shift = rhpt->shift;
1557 	struct kvm_resize_hpt *resize;
1558 	int ret;
1559 
1560 	if (flags != 0 || kvm_is_radix(kvm))
1561 		return -EINVAL;
1562 
1563 	if (shift && ((shift < 18) || (shift > 46)))
1564 		return -EINVAL;
1565 
1566 	mutex_lock(&kvm->arch.mmu_setup_lock);
1567 
1568 	resize = kvm->arch.resize_hpt;
1569 
1570 	/* This shouldn't be possible */
1571 	ret = -EIO;
1572 	if (WARN_ON(!kvm->arch.mmu_ready))
1573 		goto out_no_hpt;
1574 
1575 	/* Stop VCPUs from running while we mess with the HPT */
1576 	kvm->arch.mmu_ready = 0;
1577 	smp_mb();
1578 
1579 	/* Boot all CPUs out of the guest so they re-read
1580 	 * mmu_ready */
1581 	on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1582 
1583 	ret = -ENXIO;
1584 	if (!resize || (resize->order != shift))
1585 		goto out;
1586 
1587 	ret = resize->error;
1588 	if (ret)
1589 		goto out;
1590 
1591 	ret = resize_hpt_rehash(resize);
1592 	if (ret)
1593 		goto out;
1594 
1595 	resize_hpt_pivot(resize);
1596 
1597 out:
1598 	/* Let VCPUs run again */
1599 	kvm->arch.mmu_ready = 1;
1600 	smp_mb();
1601 out_no_hpt:
1602 	resize_hpt_release(kvm, resize);
1603 	mutex_unlock(&kvm->arch.mmu_setup_lock);
1604 	return ret;
1605 }
1606 
1607 /*
1608  * Functions for reading and writing the hash table via reads and
1609  * writes on a file descriptor.
1610  *
1611  * Reads return the guest view of the hash table, which has to be
1612  * pieced together from the real hash table and the guest_rpte
1613  * values in the revmap array.
1614  *
1615  * On writes, each HPTE written is considered in turn, and if it
1616  * is valid, it is written to the HPT as if an H_ENTER with the
1617  * exact flag set was done.  When the invalid count is non-zero
1618  * in the header written to the stream, the kernel will make
1619  * sure that that many HPTEs are invalid, and invalidate them
1620  * if not.
1621  */
1622 
1623 struct kvm_htab_ctx {
1624 	unsigned long	index;
1625 	unsigned long	flags;
1626 	struct kvm	*kvm;
1627 	int		first_pass;
1628 };
1629 
1630 #define HPTE_SIZE	(2 * sizeof(unsigned long))
1631 
1632 /*
1633  * Returns 1 if this HPT entry has been modified or has pending
1634  * R/C bit changes.
1635  */
1636 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1637 {
1638 	unsigned long rcbits_unset;
1639 
1640 	if (revp->guest_rpte & HPTE_GR_MODIFIED)
1641 		return 1;
1642 
1643 	/* Also need to consider changes in reference and changed bits */
1644 	rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1645 	if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1646 	    (be64_to_cpu(hptp[1]) & rcbits_unset))
1647 		return 1;
1648 
1649 	return 0;
1650 }
1651 
1652 static long record_hpte(unsigned long flags, __be64 *hptp,
1653 			unsigned long *hpte, struct revmap_entry *revp,
1654 			int want_valid, int first_pass)
1655 {
1656 	unsigned long v, r, hr;
1657 	unsigned long rcbits_unset;
1658 	int ok = 1;
1659 	int valid, dirty;
1660 
1661 	/* Unmodified entries are uninteresting except on the first pass */
1662 	dirty = hpte_dirty(revp, hptp);
1663 	if (!first_pass && !dirty)
1664 		return 0;
1665 
1666 	valid = 0;
1667 	if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1668 		valid = 1;
1669 		if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1670 		    !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1671 			valid = 0;
1672 	}
1673 	if (valid != want_valid)
1674 		return 0;
1675 
1676 	v = r = 0;
1677 	if (valid || dirty) {
1678 		/* lock the HPTE so it's stable and read it */
1679 		preempt_disable();
1680 		while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1681 			cpu_relax();
1682 		v = be64_to_cpu(hptp[0]);
1683 		hr = be64_to_cpu(hptp[1]);
1684 		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1685 			v = hpte_new_to_old_v(v, hr);
1686 			hr = hpte_new_to_old_r(hr);
1687 		}
1688 
1689 		/* re-evaluate valid and dirty from synchronized HPTE value */
1690 		valid = !!(v & HPTE_V_VALID);
1691 		dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1692 
1693 		/* Harvest R and C into guest view if necessary */
1694 		rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1695 		if (valid && (rcbits_unset & hr)) {
1696 			revp->guest_rpte |= (hr &
1697 				(HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1698 			dirty = 1;
1699 		}
1700 
1701 		if (v & HPTE_V_ABSENT) {
1702 			v &= ~HPTE_V_ABSENT;
1703 			v |= HPTE_V_VALID;
1704 			valid = 1;
1705 		}
1706 		if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1707 			valid = 0;
1708 
1709 		r = revp->guest_rpte;
1710 		/* only clear modified if this is the right sort of entry */
1711 		if (valid == want_valid && dirty) {
1712 			r &= ~HPTE_GR_MODIFIED;
1713 			revp->guest_rpte = r;
1714 		}
1715 		unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1716 		preempt_enable();
1717 		if (!(valid == want_valid && (first_pass || dirty)))
1718 			ok = 0;
1719 	}
1720 	hpte[0] = cpu_to_be64(v);
1721 	hpte[1] = cpu_to_be64(r);
1722 	return ok;
1723 }
1724 
1725 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1726 			     size_t count, loff_t *ppos)
1727 {
1728 	struct kvm_htab_ctx *ctx = file->private_data;
1729 	struct kvm *kvm = ctx->kvm;
1730 	struct kvm_get_htab_header hdr;
1731 	__be64 *hptp;
1732 	struct revmap_entry *revp;
1733 	unsigned long i, nb, nw;
1734 	unsigned long __user *lbuf;
1735 	struct kvm_get_htab_header __user *hptr;
1736 	unsigned long flags;
1737 	int first_pass;
1738 	unsigned long hpte[2];
1739 
1740 	if (!access_ok(buf, count))
1741 		return -EFAULT;
1742 	if (kvm_is_radix(kvm))
1743 		return 0;
1744 
1745 	first_pass = ctx->first_pass;
1746 	flags = ctx->flags;
1747 
1748 	i = ctx->index;
1749 	hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1750 	revp = kvm->arch.hpt.rev + i;
1751 	lbuf = (unsigned long __user *)buf;
1752 
1753 	nb = 0;
1754 	while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1755 		/* Initialize header */
1756 		hptr = (struct kvm_get_htab_header __user *)buf;
1757 		hdr.n_valid = 0;
1758 		hdr.n_invalid = 0;
1759 		nw = nb;
1760 		nb += sizeof(hdr);
1761 		lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1762 
1763 		/* Skip uninteresting entries, i.e. clean on not-first pass */
1764 		if (!first_pass) {
1765 			while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1766 			       !hpte_dirty(revp, hptp)) {
1767 				++i;
1768 				hptp += 2;
1769 				++revp;
1770 			}
1771 		}
1772 		hdr.index = i;
1773 
1774 		/* Grab a series of valid entries */
1775 		while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1776 		       hdr.n_valid < 0xffff &&
1777 		       nb + HPTE_SIZE < count &&
1778 		       record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1779 			/* valid entry, write it out */
1780 			++hdr.n_valid;
1781 			if (__put_user(hpte[0], lbuf) ||
1782 			    __put_user(hpte[1], lbuf + 1))
1783 				return -EFAULT;
1784 			nb += HPTE_SIZE;
1785 			lbuf += 2;
1786 			++i;
1787 			hptp += 2;
1788 			++revp;
1789 		}
1790 		/* Now skip invalid entries while we can */
1791 		while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1792 		       hdr.n_invalid < 0xffff &&
1793 		       record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1794 			/* found an invalid entry */
1795 			++hdr.n_invalid;
1796 			++i;
1797 			hptp += 2;
1798 			++revp;
1799 		}
1800 
1801 		if (hdr.n_valid || hdr.n_invalid) {
1802 			/* write back the header */
1803 			if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1804 				return -EFAULT;
1805 			nw = nb;
1806 			buf = (char __user *)lbuf;
1807 		} else {
1808 			nb = nw;
1809 		}
1810 
1811 		/* Check if we've wrapped around the hash table */
1812 		if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1813 			i = 0;
1814 			ctx->first_pass = 0;
1815 			break;
1816 		}
1817 	}
1818 
1819 	ctx->index = i;
1820 
1821 	return nb;
1822 }
1823 
1824 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1825 			      size_t count, loff_t *ppos)
1826 {
1827 	struct kvm_htab_ctx *ctx = file->private_data;
1828 	struct kvm *kvm = ctx->kvm;
1829 	struct kvm_get_htab_header hdr;
1830 	unsigned long i, j;
1831 	unsigned long v, r;
1832 	unsigned long __user *lbuf;
1833 	__be64 *hptp;
1834 	unsigned long tmp[2];
1835 	ssize_t nb;
1836 	long int err, ret;
1837 	int mmu_ready;
1838 	int pshift;
1839 
1840 	if (!access_ok(buf, count))
1841 		return -EFAULT;
1842 	if (kvm_is_radix(kvm))
1843 		return -EINVAL;
1844 
1845 	/* lock out vcpus from running while we're doing this */
1846 	mutex_lock(&kvm->arch.mmu_setup_lock);
1847 	mmu_ready = kvm->arch.mmu_ready;
1848 	if (mmu_ready) {
1849 		kvm->arch.mmu_ready = 0;	/* temporarily */
1850 		/* order mmu_ready vs. vcpus_running */
1851 		smp_mb();
1852 		if (atomic_read(&kvm->arch.vcpus_running)) {
1853 			kvm->arch.mmu_ready = 1;
1854 			mutex_unlock(&kvm->arch.mmu_setup_lock);
1855 			return -EBUSY;
1856 		}
1857 	}
1858 
1859 	err = 0;
1860 	for (nb = 0; nb + sizeof(hdr) <= count; ) {
1861 		err = -EFAULT;
1862 		if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1863 			break;
1864 
1865 		err = 0;
1866 		if (nb + hdr.n_valid * HPTE_SIZE > count)
1867 			break;
1868 
1869 		nb += sizeof(hdr);
1870 		buf += sizeof(hdr);
1871 
1872 		err = -EINVAL;
1873 		i = hdr.index;
1874 		if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1875 		    i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1876 			break;
1877 
1878 		hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1879 		lbuf = (unsigned long __user *)buf;
1880 		for (j = 0; j < hdr.n_valid; ++j) {
1881 			__be64 hpte_v;
1882 			__be64 hpte_r;
1883 
1884 			err = -EFAULT;
1885 			if (__get_user(hpte_v, lbuf) ||
1886 			    __get_user(hpte_r, lbuf + 1))
1887 				goto out;
1888 			v = be64_to_cpu(hpte_v);
1889 			r = be64_to_cpu(hpte_r);
1890 			err = -EINVAL;
1891 			if (!(v & HPTE_V_VALID))
1892 				goto out;
1893 			pshift = kvmppc_hpte_base_page_shift(v, r);
1894 			if (pshift <= 0)
1895 				goto out;
1896 			lbuf += 2;
1897 			nb += HPTE_SIZE;
1898 
1899 			if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1900 				kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1901 			err = -EIO;
1902 			ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1903 							 tmp);
1904 			if (ret != H_SUCCESS) {
1905 				pr_err("%s ret %ld i=%ld v=%lx r=%lx\n", __func__, ret, i, v, r);
1906 				goto out;
1907 			}
1908 			if (!mmu_ready && is_vrma_hpte(v)) {
1909 				unsigned long senc, lpcr;
1910 
1911 				senc = slb_pgsize_encoding(1ul << pshift);
1912 				kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1913 					(VRMA_VSID << SLB_VSID_SHIFT_1T);
1914 				if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
1915 					lpcr = senc << (LPCR_VRMASD_SH - 4);
1916 					kvmppc_update_lpcr(kvm, lpcr,
1917 							   LPCR_VRMASD);
1918 				} else {
1919 					kvmppc_setup_partition_table(kvm);
1920 				}
1921 				mmu_ready = 1;
1922 			}
1923 			++i;
1924 			hptp += 2;
1925 		}
1926 
1927 		for (j = 0; j < hdr.n_invalid; ++j) {
1928 			if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1929 				kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1930 			++i;
1931 			hptp += 2;
1932 		}
1933 		err = 0;
1934 	}
1935 
1936  out:
1937 	/* Order HPTE updates vs. mmu_ready */
1938 	smp_wmb();
1939 	kvm->arch.mmu_ready = mmu_ready;
1940 	mutex_unlock(&kvm->arch.mmu_setup_lock);
1941 
1942 	if (err)
1943 		return err;
1944 	return nb;
1945 }
1946 
1947 static int kvm_htab_release(struct inode *inode, struct file *filp)
1948 {
1949 	struct kvm_htab_ctx *ctx = filp->private_data;
1950 
1951 	filp->private_data = NULL;
1952 	if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1953 		atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1954 	kvm_put_kvm(ctx->kvm);
1955 	kfree(ctx);
1956 	return 0;
1957 }
1958 
1959 static const struct file_operations kvm_htab_fops = {
1960 	.read		= kvm_htab_read,
1961 	.write		= kvm_htab_write,
1962 	.llseek		= default_llseek,
1963 	.release	= kvm_htab_release,
1964 };
1965 
1966 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1967 {
1968 	int ret;
1969 	struct kvm_htab_ctx *ctx;
1970 	int rwflag;
1971 
1972 	/* reject flags we don't recognize */
1973 	if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1974 		return -EINVAL;
1975 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1976 	if (!ctx)
1977 		return -ENOMEM;
1978 	kvm_get_kvm(kvm);
1979 	ctx->kvm = kvm;
1980 	ctx->index = ghf->start_index;
1981 	ctx->flags = ghf->flags;
1982 	ctx->first_pass = 1;
1983 
1984 	rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1985 	ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1986 	if (ret < 0) {
1987 		kfree(ctx);
1988 		kvm_put_kvm_no_destroy(kvm);
1989 		return ret;
1990 	}
1991 
1992 	if (rwflag == O_RDONLY) {
1993 		mutex_lock(&kvm->slots_lock);
1994 		atomic_inc(&kvm->arch.hpte_mod_interest);
1995 		/* make sure kvmppc_do_h_enter etc. see the increment */
1996 		synchronize_srcu_expedited(&kvm->srcu);
1997 		mutex_unlock(&kvm->slots_lock);
1998 	}
1999 
2000 	return ret;
2001 }
2002 
2003 struct debugfs_htab_state {
2004 	struct kvm	*kvm;
2005 	struct mutex	mutex;
2006 	unsigned long	hpt_index;
2007 	int		chars_left;
2008 	int		buf_index;
2009 	char		buf[64];
2010 };
2011 
2012 static int debugfs_htab_open(struct inode *inode, struct file *file)
2013 {
2014 	struct kvm *kvm = inode->i_private;
2015 	struct debugfs_htab_state *p;
2016 
2017 	p = kzalloc(sizeof(*p), GFP_KERNEL);
2018 	if (!p)
2019 		return -ENOMEM;
2020 
2021 	kvm_get_kvm(kvm);
2022 	p->kvm = kvm;
2023 	mutex_init(&p->mutex);
2024 	file->private_data = p;
2025 
2026 	return nonseekable_open(inode, file);
2027 }
2028 
2029 static int debugfs_htab_release(struct inode *inode, struct file *file)
2030 {
2031 	struct debugfs_htab_state *p = file->private_data;
2032 
2033 	kvm_put_kvm(p->kvm);
2034 	kfree(p);
2035 	return 0;
2036 }
2037 
2038 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
2039 				 size_t len, loff_t *ppos)
2040 {
2041 	struct debugfs_htab_state *p = file->private_data;
2042 	ssize_t ret, r;
2043 	unsigned long i, n;
2044 	unsigned long v, hr, gr;
2045 	struct kvm *kvm;
2046 	__be64 *hptp;
2047 
2048 	kvm = p->kvm;
2049 	if (kvm_is_radix(kvm))
2050 		return 0;
2051 
2052 	ret = mutex_lock_interruptible(&p->mutex);
2053 	if (ret)
2054 		return ret;
2055 
2056 	if (p->chars_left) {
2057 		n = p->chars_left;
2058 		if (n > len)
2059 			n = len;
2060 		r = copy_to_user(buf, p->buf + p->buf_index, n);
2061 		n -= r;
2062 		p->chars_left -= n;
2063 		p->buf_index += n;
2064 		buf += n;
2065 		len -= n;
2066 		ret = n;
2067 		if (r) {
2068 			if (!n)
2069 				ret = -EFAULT;
2070 			goto out;
2071 		}
2072 	}
2073 
2074 	i = p->hpt_index;
2075 	hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2076 	for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2077 	     ++i, hptp += 2) {
2078 		if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2079 			continue;
2080 
2081 		/* lock the HPTE so it's stable and read it */
2082 		preempt_disable();
2083 		while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2084 			cpu_relax();
2085 		v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2086 		hr = be64_to_cpu(hptp[1]);
2087 		gr = kvm->arch.hpt.rev[i].guest_rpte;
2088 		unlock_hpte(hptp, v);
2089 		preempt_enable();
2090 
2091 		if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2092 			continue;
2093 
2094 		n = scnprintf(p->buf, sizeof(p->buf),
2095 			      "%6lx %.16lx %.16lx %.16lx\n",
2096 			      i, v, hr, gr);
2097 		p->chars_left = n;
2098 		if (n > len)
2099 			n = len;
2100 		r = copy_to_user(buf, p->buf, n);
2101 		n -= r;
2102 		p->chars_left -= n;
2103 		p->buf_index = n;
2104 		buf += n;
2105 		len -= n;
2106 		ret += n;
2107 		if (r) {
2108 			if (!ret)
2109 				ret = -EFAULT;
2110 			goto out;
2111 		}
2112 	}
2113 	p->hpt_index = i;
2114 
2115  out:
2116 	mutex_unlock(&p->mutex);
2117 	return ret;
2118 }
2119 
2120 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2121 			   size_t len, loff_t *ppos)
2122 {
2123 	return -EACCES;
2124 }
2125 
2126 static const struct file_operations debugfs_htab_fops = {
2127 	.owner	 = THIS_MODULE,
2128 	.open	 = debugfs_htab_open,
2129 	.release = debugfs_htab_release,
2130 	.read	 = debugfs_htab_read,
2131 	.write	 = debugfs_htab_write,
2132 	.llseek	 = generic_file_llseek,
2133 };
2134 
2135 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2136 {
2137 	debugfs_create_file("htab", 0400, kvm->debugfs_dentry, kvm,
2138 			    &debugfs_htab_fops);
2139 }
2140 
2141 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2142 {
2143 	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2144 
2145 	vcpu->arch.slb_nr = 32;		/* POWER7/POWER8 */
2146 
2147 	mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2148 
2149 	vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2150 }
2151