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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux/fpc-iii.git] / arch / powerpc / kvm / book3s_64_mmu_hv.c
blob303ece75b8e4aa5b798381b4cf782a3dde8b79f6
1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
14 *
15 * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
16 */
17
18 #include <linux/types.h>
19 #include <linux/string.h>
20 #include <linux/kvm.h>
21 #include <linux/kvm_host.h>
22 #include <linux/highmem.h>
23 #include <linux/gfp.h>
24 #include <linux/slab.h>
25 #include <linux/hugetlb.h>
26 #include <linux/vmalloc.h>
27 #include <linux/srcu.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/file.h>
30
31 #include <asm/tlbflush.h>
32 #include <asm/kvm_ppc.h>
33 #include <asm/kvm_book3s.h>
34 #include <asm/mmu-hash64.h>
35 #include <asm/hvcall.h>
36 #include <asm/synch.h>
37 #include <asm/ppc-opcode.h>
38 #include <asm/cputable.h>
39
40 #include "book3s_hv_cma.h"
41
42 /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
43 #define MAX_LPID_970 63
44
45 /* Power architecture requires HPT is at least 256kB */
46 #define PPC_MIN_HPT_ORDER 18
47
48 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
49 long pte_index, unsigned long pteh,
50 unsigned long ptel, unsigned long *pte_idx_ret);
51 static void kvmppc_rmap_reset(struct kvm *kvm);
52
53 long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
54 {
55 unsigned long hpt;
56 struct revmap_entry *rev;
57 struct page *page = NULL;
58 long order = KVM_DEFAULT_HPT_ORDER;
59
60 if (htab_orderp) {
61 order = *htab_orderp;
62 if (order < PPC_MIN_HPT_ORDER)
63 order = PPC_MIN_HPT_ORDER;
64 }
65
66 kvm->arch.hpt_cma_alloc = 0;
67 /*
68 * try first to allocate it from the kernel page allocator.
69 * We keep the CMA reserved for failed allocation.
70 */
71 hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT |
72 __GFP_NOWARN, order - PAGE_SHIFT);
73
74 /* Next try to allocate from the preallocated pool */
75 if (!hpt) {
76 VM_BUG_ON(order < KVM_CMA_CHUNK_ORDER);
77 page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
78 if (page) {
79 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
80 kvm->arch.hpt_cma_alloc = 1;
81 } else
82 --order;
83 }
84
85 /* Lastly try successively smaller sizes from the page allocator */
86 while (!hpt && order > PPC_MIN_HPT_ORDER) {
87 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
88 __GFP_NOWARN, order - PAGE_SHIFT);
89 if (!hpt)
90 --order;
91 }
92
93 if (!hpt)
94 return -ENOMEM;
95
96 kvm->arch.hpt_virt = hpt;
97 kvm->arch.hpt_order = order;
98 /* HPTEs are 2**4 bytes long */
99 kvm->arch.hpt_npte = 1ul << (order - 4);
100 /* 128 (2**7) bytes in each HPTEG */
101 kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
102
103 /* Allocate reverse map array */
104 rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
105 if (!rev) {
106 pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
107 goto out_freehpt;
108 }
109 kvm->arch.revmap = rev;
110 kvm->arch.sdr1 = __pa(hpt) | (order - 18);
111
112 pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
113 hpt, order, kvm->arch.lpid);
114
115 if (htab_orderp)
116 *htab_orderp = order;
117 return 0;
118
119 out_freehpt:
120 if (kvm->arch.hpt_cma_alloc)
121 kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
122 else
123 free_pages(hpt, order - PAGE_SHIFT);
124 return -ENOMEM;
125 }
126
127 long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
128 {
129 long err = -EBUSY;
130 long order;
131
132 mutex_lock(&kvm->lock);
133 if (kvm->arch.rma_setup_done) {
134 kvm->arch.rma_setup_done = 0;
135 /* order rma_setup_done vs. vcpus_running */
136 smp_mb();
137 if (atomic_read(&kvm->arch.vcpus_running)) {
138 kvm->arch.rma_setup_done = 1;
139 goto out;
140 }
141 }
142 if (kvm->arch.hpt_virt) {
143 order = kvm->arch.hpt_order;
144 /* Set the entire HPT to 0, i.e. invalid HPTEs */
145 memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
146 /*
147 * Reset all the reverse-mapping chains for all memslots
148 */
149 kvmppc_rmap_reset(kvm);
150 /* Ensure that each vcpu will flush its TLB on next entry. */
151 cpumask_setall(&kvm->arch.need_tlb_flush);
152 *htab_orderp = order;
153 err = 0;
154 } else {
155 err = kvmppc_alloc_hpt(kvm, htab_orderp);
156 order = *htab_orderp;
157 }
158 out:
159 mutex_unlock(&kvm->lock);
160 return err;
161 }
162
163 void kvmppc_free_hpt(struct kvm *kvm)
164 {
165 kvmppc_free_lpid(kvm->arch.lpid);
166 vfree(kvm->arch.revmap);
167 if (kvm->arch.hpt_cma_alloc)
168 kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
169 1 << (kvm->arch.hpt_order - PAGE_SHIFT));
170 else
171 free_pages(kvm->arch.hpt_virt,
172 kvm->arch.hpt_order - PAGE_SHIFT);
173 }
174
175 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
176 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
177 {
178 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
179 }
180
181 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
182 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
183 {
184 return (pgsize == 0x10000) ? 0x1000 : 0;
185 }
186
187 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
188 unsigned long porder)
189 {
190 unsigned long i;
191 unsigned long npages;
192 unsigned long hp_v, hp_r;
193 unsigned long addr, hash;
194 unsigned long psize;
195 unsigned long hp0, hp1;
196 unsigned long idx_ret;
197 long ret;
198 struct kvm *kvm = vcpu->kvm;
199
200 psize = 1ul << porder;
201 npages = memslot->npages >> (porder - PAGE_SHIFT);
202
203 /* VRMA can't be > 1TB */
204 if (npages > 1ul << (40 - porder))
205 npages = 1ul << (40 - porder);
206 /* Can't use more than 1 HPTE per HPTEG */
207 if (npages > kvm->arch.hpt_mask + 1)
208 npages = kvm->arch.hpt_mask + 1;
209
210 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
211 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
212 hp1 = hpte1_pgsize_encoding(psize) |
213 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
214
215 for (i = 0; i < npages; ++i) {
216 addr = i << porder;
217 /* can't use hpt_hash since va > 64 bits */
218 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
219 /*
220 * We assume that the hash table is empty and no
221 * vcpus are using it at this stage. Since we create
222 * at most one HPTE per HPTEG, we just assume entry 7
223 * is available and use it.
224 */
225 hash = (hash << 3) + 7;
226 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
227 hp_r = hp1 | addr;
228 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
229 &idx_ret);
230 if (ret != H_SUCCESS) {
231 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
232 addr, ret);
233 break;
234 }
235 }
236 }
237
238 int kvmppc_mmu_hv_init(void)
239 {
240 unsigned long host_lpid, rsvd_lpid;
241
242 if (!cpu_has_feature(CPU_FTR_HVMODE))
243 return -EINVAL;
244
245 /* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */
246 if (cpu_has_feature(CPU_FTR_ARCH_206)) {
247 host_lpid = mfspr(SPRN_LPID); /* POWER7 */
248 rsvd_lpid = LPID_RSVD;
249 } else {
250 host_lpid = 0; /* PPC970 */
251 rsvd_lpid = MAX_LPID_970;
252 }
253
254 kvmppc_init_lpid(rsvd_lpid + 1);
255
256 kvmppc_claim_lpid(host_lpid);
257 /* rsvd_lpid is reserved for use in partition switching */
258 kvmppc_claim_lpid(rsvd_lpid);
259
260 return 0;
261 }
262
263 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
264 {
265 kvmppc_set_msr(vcpu, vcpu->arch.intr_msr);
266 }
267
268 /*
269 * This is called to get a reference to a guest page if there isn't
270 * one already in the memslot->arch.slot_phys[] array.
271 */
272 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
273 struct kvm_memory_slot *memslot,
274 unsigned long psize)
275 {
276 unsigned long start;
277 long np, err;
278 struct page *page, *hpage, *pages[1];
279 unsigned long s, pgsize;
280 unsigned long *physp;
281 unsigned int is_io, got, pgorder;
282 struct vm_area_struct *vma;
283 unsigned long pfn, i, npages;
284
285 physp = memslot->arch.slot_phys;
286 if (!physp)
287 return -EINVAL;
288 if (physp[gfn - memslot->base_gfn])
289 return 0;
290
291 is_io = 0;
292 got = 0;
293 page = NULL;
294 pgsize = psize;
295 err = -EINVAL;
296 start = gfn_to_hva_memslot(memslot, gfn);
297
298 /* Instantiate and get the page we want access to */
299 np = get_user_pages_fast(start, 1, 1, pages);
300 if (np != 1) {
301 /* Look up the vma for the page */
302 down_read(&current->mm->mmap_sem);
303 vma = find_vma(current->mm, start);
304 if (!vma || vma->vm_start > start ||
305 start + psize > vma->vm_end ||
306 !(vma->vm_flags & VM_PFNMAP))
307 goto up_err;
308 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
309 pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
310 /* check alignment of pfn vs. requested page size */
311 if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
312 goto up_err;
313 up_read(&current->mm->mmap_sem);
314
315 } else {
316 page = pages[0];
317 got = KVMPPC_GOT_PAGE;
318
319 /* See if this is a large page */
320 s = PAGE_SIZE;
321 if (PageHuge(page)) {
322 hpage = compound_head(page);
323 s <<= compound_order(hpage);
324 /* Get the whole large page if slot alignment is ok */
325 if (s > psize && slot_is_aligned(memslot, s) &&
326 !(memslot->userspace_addr & (s - 1))) {
327 start &= ~(s - 1);
328 pgsize = s;
329 get_page(hpage);
330 put_page(page);
331 page = hpage;
332 }
333 }
334 if (s < psize)
335 goto out;
336 pfn = page_to_pfn(page);
337 }
338
339 npages = pgsize >> PAGE_SHIFT;
340 pgorder = __ilog2(npages);
341 physp += (gfn - memslot->base_gfn) & ~(npages - 1);
342 spin_lock(&kvm->arch.slot_phys_lock);
343 for (i = 0; i < npages; ++i) {
344 if (!physp[i]) {
345 physp[i] = ((pfn + i) << PAGE_SHIFT) +
346 got + is_io + pgorder;
347 got = 0;
348 }
349 }
350 spin_unlock(&kvm->arch.slot_phys_lock);
351 err = 0;
352
353 out:
354 if (got)
355 put_page(page);
356 return err;
357
358 up_err:
359 up_read(&current->mm->mmap_sem);
360 return err;
361 }
362
363 long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
364 long pte_index, unsigned long pteh,
365 unsigned long ptel, unsigned long *pte_idx_ret)
366 {
367 unsigned long psize, gpa, gfn;
368 struct kvm_memory_slot *memslot;
369 long ret;
370
371 if (kvm->arch.using_mmu_notifiers)
372 goto do_insert;
373
374 psize = hpte_page_size(pteh, ptel);
375 if (!psize)
376 return H_PARAMETER;
377
378 pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
379
380 /* Find the memslot (if any) for this address */
381 gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
382 gfn = gpa >> PAGE_SHIFT;
383 memslot = gfn_to_memslot(kvm, gfn);
384 if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
385 if (!slot_is_aligned(memslot, psize))
386 return H_PARAMETER;
387 if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
388 return H_PARAMETER;
389 }
390
391 do_insert:
392 /* Protect linux PTE lookup from page table destruction */
393 rcu_read_lock_sched(); /* this disables preemption too */
394 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
395 current->mm->pgd, false, pte_idx_ret);
396 rcu_read_unlock_sched();
397 if (ret == H_TOO_HARD) {
398 /* this can't happen */
399 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
400 ret = H_RESOURCE; /* or something */
401 }
402 return ret;
403
404 }
405
406 /*
407 * We come here on a H_ENTER call from the guest when we are not
408 * using mmu notifiers and we don't have the requested page pinned
409 * already.
410 */
411 long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
412 long pte_index, unsigned long pteh,
413 unsigned long ptel)
414 {
415 return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index,
416 pteh, ptel, &vcpu->arch.gpr[4]);
417 }
418
419 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
420 gva_t eaddr)
421 {
422 u64 mask;
423 int i;
424
425 for (i = 0; i < vcpu->arch.slb_nr; i++) {
426 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
427 continue;
428
429 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
430 mask = ESID_MASK_1T;
431 else
432 mask = ESID_MASK;
433
434 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
435 return &vcpu->arch.slb[i];
436 }
437 return NULL;
438 }
439
440 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
441 unsigned long ea)
442 {
443 unsigned long ra_mask;
444
445 ra_mask = hpte_page_size(v, r) - 1;
446 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
447 }
448
449 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
450 struct kvmppc_pte *gpte, bool data, bool iswrite)
451 {
452 struct kvm *kvm = vcpu->kvm;
453 struct kvmppc_slb *slbe;
454 unsigned long slb_v;
455 unsigned long pp, key;
456 unsigned long v, gr;
457 unsigned long *hptep;
458 int index;
459 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
460
461 /* Get SLB entry */
462 if (virtmode) {
463 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
464 if (!slbe)
465 return -EINVAL;
466 slb_v = slbe->origv;
467 } else {
468 /* real mode access */
469 slb_v = vcpu->kvm->arch.vrma_slb_v;
470 }
471
472 preempt_disable();
473 /* Find the HPTE in the hash table */
474 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
475 HPTE_V_VALID | HPTE_V_ABSENT);
476 if (index < 0) {
477 preempt_enable();
478 return -ENOENT;
479 }
480 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
481 v = hptep[0] & ~HPTE_V_HVLOCK;
482 gr = kvm->arch.revmap[index].guest_rpte;
483
484 /* Unlock the HPTE */
485 asm volatile("lwsync" : : : "memory");
486 hptep[0] = v;
487 preempt_enable();
488
489 gpte->eaddr = eaddr;
490 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
491
492 /* Get PP bits and key for permission check */
493 pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
494 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
495 key &= slb_v;
496
497 /* Calculate permissions */
498 gpte->may_read = hpte_read_permission(pp, key);
499 gpte->may_write = hpte_write_permission(pp, key);
500 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
501
502 /* Storage key permission check for POWER7 */
503 if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
504 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
505 if (amrfield & 1)
506 gpte->may_read = 0;
507 if (amrfield & 2)
508 gpte->may_write = 0;
509 }
510
511 /* Get the guest physical address */
512 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
513 return 0;
514 }
515
516 /*
517 * Quick test for whether an instruction is a load or a store.
518 * If the instruction is a load or a store, then this will indicate
519 * which it is, at least on server processors. (Embedded processors
520 * have some external PID instructions that don't follow the rule
521 * embodied here.) If the instruction isn't a load or store, then
522 * this doesn't return anything useful.
523 */
524 static int instruction_is_store(unsigned int instr)
525 {
526 unsigned int mask;
527
528 mask = 0x10000000;
529 if ((instr & 0xfc000000) == 0x7c000000)
530 mask = 0x100; /* major opcode 31 */
531 return (instr & mask) != 0;
532 }
533
534 static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
535 unsigned long gpa, gva_t ea, int is_store)
536 {
537 int ret;
538 u32 last_inst;
539 unsigned long srr0 = kvmppc_get_pc(vcpu);
540
541 /* We try to load the last instruction. We don't let
542 * emulate_instruction do it as it doesn't check what
543 * kvmppc_ld returns.
544 * If we fail, we just return to the guest and try executing it again.
545 */
546 if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) {
547 ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
548 if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED)
549 return RESUME_GUEST;
550 vcpu->arch.last_inst = last_inst;
551 }
552
553 /*
554 * WARNING: We do not know for sure whether the instruction we just
555 * read from memory is the same that caused the fault in the first
556 * place. If the instruction we read is neither an load or a store,
557 * then it can't access memory, so we don't need to worry about
558 * enforcing access permissions. So, assuming it is a load or
559 * store, we just check that its direction (load or store) is
560 * consistent with the original fault, since that's what we
561 * checked the access permissions against. If there is a mismatch
562 * we just return and retry the instruction.
563 */
564
565 if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store)
566 return RESUME_GUEST;
567
568 /*
569 * Emulated accesses are emulated by looking at the hash for
570 * translation once, then performing the access later. The
571 * translation could be invalidated in the meantime in which
572 * point performing the subsequent memory access on the old
573 * physical address could possibly be a security hole for the
574 * guest (but not the host).
575 *
576 * This is less of an issue for MMIO stores since they aren't
577 * globally visible. It could be an issue for MMIO loads to
578 * a certain extent but we'll ignore it for now.
579 */
580
581 vcpu->arch.paddr_accessed = gpa;
582 vcpu->arch.vaddr_accessed = ea;
583 return kvmppc_emulate_mmio(run, vcpu);
584 }
585
586 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
587 unsigned long ea, unsigned long dsisr)
588 {
589 struct kvm *kvm = vcpu->kvm;
590 unsigned long *hptep, hpte[3], r;
591 unsigned long mmu_seq, psize, pte_size;
592 unsigned long gpa, gfn, hva, pfn;
593 struct kvm_memory_slot *memslot;
594 unsigned long *rmap;
595 struct revmap_entry *rev;
596 struct page *page, *pages[1];
597 long index, ret, npages;
598 unsigned long is_io;
599 unsigned int writing, write_ok;
600 struct vm_area_struct *vma;
601 unsigned long rcbits;
602
603 /*
604 * Real-mode code has already searched the HPT and found the
605 * entry we're interested in. Lock the entry and check that
606 * it hasn't changed. If it has, just return and re-execute the
607 * instruction.
608 */
609 if (ea != vcpu->arch.pgfault_addr)
610 return RESUME_GUEST;
611 index = vcpu->arch.pgfault_index;
612 hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4));
613 rev = &kvm->arch.revmap[index];
614 preempt_disable();
615 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
616 cpu_relax();
617 hpte[0] = hptep[0] & ~HPTE_V_HVLOCK;
618 hpte[1] = hptep[1];
619 hpte[2] = r = rev->guest_rpte;
620 asm volatile("lwsync" : : : "memory");
621 hptep[0] = hpte[0];
622 preempt_enable();
623
624 if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
625 hpte[1] != vcpu->arch.pgfault_hpte[1])
626 return RESUME_GUEST;
627
628 /* Translate the logical address and get the page */
629 psize = hpte_page_size(hpte[0], r);
630 gpa = (r & HPTE_R_RPN & ~(psize - 1)) | (ea & (psize - 1));
631 gfn = gpa >> PAGE_SHIFT;
632 memslot = gfn_to_memslot(kvm, gfn);
633
634 /* No memslot means it's an emulated MMIO region */
635 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
636 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
637 dsisr & DSISR_ISSTORE);
638
639 if (!kvm->arch.using_mmu_notifiers)
640 return -EFAULT; /* should never get here */
641
642 /* used to check for invalidations in progress */
643 mmu_seq = kvm->mmu_notifier_seq;
644 smp_rmb();
645
646 is_io = 0;
647 pfn = 0;
648 page = NULL;
649 pte_size = PAGE_SIZE;
650 writing = (dsisr & DSISR_ISSTORE) != 0;
651 /* If writing != 0, then the HPTE must allow writing, if we get here */
652 write_ok = writing;
653 hva = gfn_to_hva_memslot(memslot, gfn);
654 npages = get_user_pages_fast(hva, 1, writing, pages);
655 if (npages < 1) {
656 /* Check if it's an I/O mapping */
657 down_read(&current->mm->mmap_sem);
658 vma = find_vma(current->mm, hva);
659 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
660 (vma->vm_flags & VM_PFNMAP)) {
661 pfn = vma->vm_pgoff +
662 ((hva - vma->vm_start) >> PAGE_SHIFT);
663 pte_size = psize;
664 is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
665 write_ok = vma->vm_flags & VM_WRITE;
666 }
667 up_read(&current->mm->mmap_sem);
668 if (!pfn)
669 return -EFAULT;
670 } else {
671 page = pages[0];
672 pfn = page_to_pfn(page);
673 if (PageHuge(page)) {
674 page = compound_head(page);
675 pte_size <<= compound_order(page);
676 }
677 /* if the guest wants write access, see if that is OK */
678 if (!writing && hpte_is_writable(r)) {
679 unsigned int hugepage_shift;
680 pte_t *ptep, pte;
681
682 /*
683 * We need to protect against page table destruction
684 * while looking up and updating the pte.
685 */
686 rcu_read_lock_sched();
687 ptep = find_linux_pte_or_hugepte(current->mm->pgd,
688 hva, &hugepage_shift);
689 if (ptep) {
690 pte = kvmppc_read_update_linux_pte(ptep, 1,
691 hugepage_shift);
692 if (pte_write(pte))
693 write_ok = 1;
694 }
695 rcu_read_unlock_sched();
696 }
697 }
698
699 ret = -EFAULT;
700 if (psize > pte_size)
701 goto out_put;
702
703 /* Check WIMG vs. the actual page we're accessing */
704 if (!hpte_cache_flags_ok(r, is_io)) {
705 if (is_io)
706 return -EFAULT;
707 /*
708 * Allow guest to map emulated device memory as
709 * uncacheable, but actually make it cacheable.
710 */
711 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
712 }
713
714 /*
715 * Set the HPTE to point to pfn.
716 * Since the pfn is at PAGE_SIZE granularity, make sure we
717 * don't mask out lower-order bits if psize < PAGE_SIZE.
718 */
719 if (psize < PAGE_SIZE)
720 psize = PAGE_SIZE;
721 r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1));
722 if (hpte_is_writable(r) && !write_ok)
723 r = hpte_make_readonly(r);
724 ret = RESUME_GUEST;
725 preempt_disable();
726 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
727 cpu_relax();
728 if ((hptep[0] & ~HPTE_V_HVLOCK) != hpte[0] || hptep[1] != hpte[1] ||
729 rev->guest_rpte != hpte[2])
730 /* HPTE has been changed under us; let the guest retry */
731 goto out_unlock;
732 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
733
734 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
735 lock_rmap(rmap);
736
737 /* Check if we might have been invalidated; let the guest retry if so */
738 ret = RESUME_GUEST;
739 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
740 unlock_rmap(rmap);
741 goto out_unlock;
742 }
743
744 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
745 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
746 r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
747
748 if (hptep[0] & HPTE_V_VALID) {
749 /* HPTE was previously valid, so we need to invalidate it */
750 unlock_rmap(rmap);
751 hptep[0] |= HPTE_V_ABSENT;
752 kvmppc_invalidate_hpte(kvm, hptep, index);
753 /* don't lose previous R and C bits */
754 r |= hptep[1] & (HPTE_R_R | HPTE_R_C);
755 } else {
756 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
757 }
758
759 hptep[1] = r;
760 eieio();
761 hptep[0] = hpte[0];
762 asm volatile("ptesync" : : : "memory");
763 preempt_enable();
764 if (page && hpte_is_writable(r))
765 SetPageDirty(page);
766
767 out_put:
768 if (page) {
769 /*
770 * We drop pages[0] here, not page because page might
771 * have been set to the head page of a compound, but
772 * we have to drop the reference on the correct tail
773 * page to match the get inside gup()
774 */
775 put_page(pages[0]);
776 }
777 return ret;
778
779 out_unlock:
780 hptep[0] &= ~HPTE_V_HVLOCK;
781 preempt_enable();
782 goto out_put;
783 }
784
785 static void kvmppc_rmap_reset(struct kvm *kvm)
786 {
787 struct kvm_memslots *slots;
788 struct kvm_memory_slot *memslot;
789 int srcu_idx;
790
791 srcu_idx = srcu_read_lock(&kvm->srcu);
792 slots = kvm->memslots;
793 kvm_for_each_memslot(memslot, slots) {
794 /*
795 * This assumes it is acceptable to lose reference and
796 * change bits across a reset.
797 */
798 memset(memslot->arch.rmap, 0,
799 memslot->npages * sizeof(*memslot->arch.rmap));
800 }
801 srcu_read_unlock(&kvm->srcu, srcu_idx);
802 }
803
804 static int kvm_handle_hva_range(struct kvm *kvm,
805 unsigned long start,
806 unsigned long end,
807 int (*handler)(struct kvm *kvm,
808 unsigned long *rmapp,
809 unsigned long gfn))
810 {
811 int ret;
812 int retval = 0;
813 struct kvm_memslots *slots;
814 struct kvm_memory_slot *memslot;
815
816 slots = kvm_memslots(kvm);
817 kvm_for_each_memslot(memslot, slots) {
818 unsigned long hva_start, hva_end;
819 gfn_t gfn, gfn_end;
820
821 hva_start = max(start, memslot->userspace_addr);
822 hva_end = min(end, memslot->userspace_addr +
823 (memslot->npages << PAGE_SHIFT));
824 if (hva_start >= hva_end)
825 continue;
826 /*
827 * {gfn(page) | page intersects with [hva_start, hva_end)} =
828 * {gfn, gfn+1, ..., gfn_end-1}.
829 */
830 gfn = hva_to_gfn_memslot(hva_start, memslot);
831 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
832
833 for (; gfn < gfn_end; ++gfn) {
834 gfn_t gfn_offset = gfn - memslot->base_gfn;
835
836 ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
837 retval |= ret;
838 }
839 }
840
841 return retval;
842 }
843
844 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
845 int (*handler)(struct kvm *kvm, unsigned long *rmapp,
846 unsigned long gfn))
847 {
848 return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
849 }
850
851 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
852 unsigned long gfn)
853 {
854 struct revmap_entry *rev = kvm->arch.revmap;
855 unsigned long h, i, j;
856 unsigned long *hptep;
857 unsigned long ptel, psize, rcbits;
858
859 for (;;) {
860 lock_rmap(rmapp);
861 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
862 unlock_rmap(rmapp);
863 break;
864 }
865
866 /*
867 * To avoid an ABBA deadlock with the HPTE lock bit,
868 * we can't spin on the HPTE lock while holding the
869 * rmap chain lock.
870 */
871 i = *rmapp & KVMPPC_RMAP_INDEX;
872 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
873 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
874 /* unlock rmap before spinning on the HPTE lock */
875 unlock_rmap(rmapp);
876 while (hptep[0] & HPTE_V_HVLOCK)
877 cpu_relax();
878 continue;
879 }
880 j = rev[i].forw;
881 if (j == i) {
882 /* chain is now empty */
883 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
884 } else {
885 /* remove i from chain */
886 h = rev[i].back;
887 rev[h].forw = j;
888 rev[j].back = h;
889 rev[i].forw = rev[i].back = i;
890 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
891 }
892
893 /* Now check and modify the HPTE */
894 ptel = rev[i].guest_rpte;
895 psize = hpte_page_size(hptep[0], ptel);
896 if ((hptep[0] & HPTE_V_VALID) &&
897 hpte_rpn(ptel, psize) == gfn) {
898 if (kvm->arch.using_mmu_notifiers)
899 hptep[0] |= HPTE_V_ABSENT;
900 kvmppc_invalidate_hpte(kvm, hptep, i);
901 /* Harvest R and C */
902 rcbits = hptep[1] & (HPTE_R_R | HPTE_R_C);
903 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
904 if (rcbits & ~rev[i].guest_rpte) {
905 rev[i].guest_rpte = ptel | rcbits;
906 note_hpte_modification(kvm, &rev[i]);
907 }
908 }
909 unlock_rmap(rmapp);
910 hptep[0] &= ~HPTE_V_HVLOCK;
911 }
912 return 0;
913 }
914
915 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
916 {
917 if (kvm->arch.using_mmu_notifiers)
918 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
919 return 0;
920 }
921
922 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
923 {
924 if (kvm->arch.using_mmu_notifiers)
925 kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
926 return 0;
927 }
928
929 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
930 struct kvm_memory_slot *memslot)
931 {
932 unsigned long *rmapp;
933 unsigned long gfn;
934 unsigned long n;
935
936 rmapp = memslot->arch.rmap;
937 gfn = memslot->base_gfn;
938 for (n = memslot->npages; n; --n) {
939 /*
940 * Testing the present bit without locking is OK because
941 * the memslot has been marked invalid already, and hence
942 * no new HPTEs referencing this page can be created,
943 * thus the present bit can't go from 0 to 1.
944 */
945 if (*rmapp & KVMPPC_RMAP_PRESENT)
946 kvm_unmap_rmapp(kvm, rmapp, gfn);
947 ++rmapp;
948 ++gfn;
949 }
950 }
951
952 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
953 unsigned long gfn)
954 {
955 struct revmap_entry *rev = kvm->arch.revmap;
956 unsigned long head, i, j;
957 unsigned long *hptep;
958 int ret = 0;
959
960 retry:
961 lock_rmap(rmapp);
962 if (*rmapp & KVMPPC_RMAP_REFERENCED) {
963 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
964 ret = 1;
965 }
966 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
967 unlock_rmap(rmapp);
968 return ret;
969 }
970
971 i = head = *rmapp & KVMPPC_RMAP_INDEX;
972 do {
973 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
974 j = rev[i].forw;
975
976 /* If this HPTE isn't referenced, ignore it */
977 if (!(hptep[1] & HPTE_R_R))
978 continue;
979
980 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
981 /* unlock rmap before spinning on the HPTE lock */
982 unlock_rmap(rmapp);
983 while (hptep[0] & HPTE_V_HVLOCK)
984 cpu_relax();
985 goto retry;
986 }
987
988 /* Now check and modify the HPTE */
989 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) {
990 kvmppc_clear_ref_hpte(kvm, hptep, i);
991 if (!(rev[i].guest_rpte & HPTE_R_R)) {
992 rev[i].guest_rpte |= HPTE_R_R;
993 note_hpte_modification(kvm, &rev[i]);
994 }
995 ret = 1;
996 }
997 hptep[0] &= ~HPTE_V_HVLOCK;
998 } while ((i = j) != head);
999
1000 unlock_rmap(rmapp);
1001 return ret;
1002 }
1003
1004 int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva)
1005 {
1006 if (!kvm->arch.using_mmu_notifiers)
1007 return 0;
1008 return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
1009 }
1010
1011 static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
1012 unsigned long gfn)
1013 {
1014 struct revmap_entry *rev = kvm->arch.revmap;
1015 unsigned long head, i, j;
1016 unsigned long *hp;
1017 int ret = 1;
1018
1019 if (*rmapp & KVMPPC_RMAP_REFERENCED)
1020 return 1;
1021
1022 lock_rmap(rmapp);
1023 if (*rmapp & KVMPPC_RMAP_REFERENCED)
1024 goto out;
1025
1026 if (*rmapp & KVMPPC_RMAP_PRESENT) {
1027 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1028 do {
1029 hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
1030 j = rev[i].forw;
1031 if (hp[1] & HPTE_R_R)
1032 goto out;
1033 } while ((i = j) != head);
1034 }
1035 ret = 0;
1036
1037 out:
1038 unlock_rmap(rmapp);
1039 return ret;
1040 }
1041
1042 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1043 {
1044 if (!kvm->arch.using_mmu_notifiers)
1045 return 0;
1046 return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
1047 }
1048
1049 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1050 {
1051 if (!kvm->arch.using_mmu_notifiers)
1052 return;
1053 kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
1054 }
1055
1056 static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp)
1057 {
1058 struct revmap_entry *rev = kvm->arch.revmap;
1059 unsigned long head, i, j;
1060 unsigned long *hptep;
1061 int ret = 0;
1062
1063 retry:
1064 lock_rmap(rmapp);
1065 if (*rmapp & KVMPPC_RMAP_CHANGED) {
1066 *rmapp &= ~KVMPPC_RMAP_CHANGED;
1067 ret = 1;
1068 }
1069 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1070 unlock_rmap(rmapp);
1071 return ret;
1072 }
1073
1074 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1075 do {
1076 hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4));
1077 j = rev[i].forw;
1078
1079 if (!(hptep[1] & HPTE_R_C))
1080 continue;
1081
1082 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1083 /* unlock rmap before spinning on the HPTE lock */
1084 unlock_rmap(rmapp);
1085 while (hptep[0] & HPTE_V_HVLOCK)
1086 cpu_relax();
1087 goto retry;
1088 }
1089
1090 /* Now check and modify the HPTE */
1091 if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_C)) {
1092 /* need to make it temporarily absent to clear C */
1093 hptep[0] |= HPTE_V_ABSENT;
1094 kvmppc_invalidate_hpte(kvm, hptep, i);
1095 hptep[1] &= ~HPTE_R_C;
1096 eieio();
1097 hptep[0] = (hptep[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
1098 if (!(rev[i].guest_rpte & HPTE_R_C)) {
1099 rev[i].guest_rpte |= HPTE_R_C;
1100 note_hpte_modification(kvm, &rev[i]);
1101 }
1102 ret = 1;
1103 }
1104 hptep[0] &= ~HPTE_V_HVLOCK;
1105 } while ((i = j) != head);
1106
1107 unlock_rmap(rmapp);
1108 return ret;
1109 }
1110
1111 static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1112 struct kvm_memory_slot *memslot,
1113 unsigned long *map)
1114 {
1115 unsigned long gfn;
1116
1117 if (!vpa->dirty || !vpa->pinned_addr)
1118 return;
1119 gfn = vpa->gpa >> PAGE_SHIFT;
1120 if (gfn < memslot->base_gfn ||
1121 gfn >= memslot->base_gfn + memslot->npages)
1122 return;
1123
1124 vpa->dirty = false;
1125 if (map)
1126 __set_bit_le(gfn - memslot->base_gfn, map);
1127 }
1128
1129 long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
1130 unsigned long *map)
1131 {
1132 unsigned long i;
1133 unsigned long *rmapp;
1134 struct kvm_vcpu *vcpu;
1135
1136 preempt_disable();
1137 rmapp = memslot->arch.rmap;
1138 for (i = 0; i < memslot->npages; ++i) {
1139 if (kvm_test_clear_dirty(kvm, rmapp) && map)
1140 __set_bit_le(i, map);
1141 ++rmapp;
1142 }
1143
1144 /* Harvest dirty bits from VPA and DTL updates */
1145 /* Note: we never modify the SLB shadow buffer areas */
1146 kvm_for_each_vcpu(i, vcpu, kvm) {
1147 spin_lock(&vcpu->arch.vpa_update_lock);
1148 harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
1149 harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
1150 spin_unlock(&vcpu->arch.vpa_update_lock);
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 unsigned long pa;
1165 unsigned long *physp;
1166 int srcu_idx;
1167
1168 srcu_idx = srcu_read_lock(&kvm->srcu);
1169 memslot = gfn_to_memslot(kvm, gfn);
1170 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1171 goto err;
1172 if (!kvm->arch.using_mmu_notifiers) {
1173 physp = memslot->arch.slot_phys;
1174 if (!physp)
1175 goto err;
1176 physp += gfn - memslot->base_gfn;
1177 pa = *physp;
1178 if (!pa) {
1179 if (kvmppc_get_guest_page(kvm, gfn, memslot,
1180 PAGE_SIZE) < 0)
1181 goto err;
1182 pa = *physp;
1183 }
1184 page = pfn_to_page(pa >> PAGE_SHIFT);
1185 get_page(page);
1186 } else {
1187 hva = gfn_to_hva_memslot(memslot, gfn);
1188 npages = get_user_pages_fast(hva, 1, 1, pages);
1189 if (npages < 1)
1190 goto err;
1191 page = pages[0];
1192 }
1193 srcu_read_unlock(&kvm->srcu, srcu_idx);
1194
1195 offset = gpa & (PAGE_SIZE - 1);
1196 if (nb_ret)
1197 *nb_ret = PAGE_SIZE - offset;
1198 return page_address(page) + offset;
1199
1200 err:
1201 srcu_read_unlock(&kvm->srcu, srcu_idx);
1202 return NULL;
1203 }
1204
1205 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1206 bool dirty)
1207 {
1208 struct page *page = virt_to_page(va);
1209 struct kvm_memory_slot *memslot;
1210 unsigned long gfn;
1211 unsigned long *rmap;
1212 int srcu_idx;
1213
1214 put_page(page);
1215
1216 if (!dirty || !kvm->arch.using_mmu_notifiers)
1217 return;
1218
1219 /* We need to mark this page dirty in the rmap chain */
1220 gfn = gpa >> PAGE_SHIFT;
1221 srcu_idx = srcu_read_lock(&kvm->srcu);
1222 memslot = gfn_to_memslot(kvm, gfn);
1223 if (memslot) {
1224 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1225 lock_rmap(rmap);
1226 *rmap |= KVMPPC_RMAP_CHANGED;
1227 unlock_rmap(rmap);
1228 }
1229 srcu_read_unlock(&kvm->srcu, srcu_idx);
1230 }
1231
1232 /*
1233 * Functions for reading and writing the hash table via reads and
1234 * writes on a file descriptor.
1235 *
1236 * Reads return the guest view of the hash table, which has to be
1237 * pieced together from the real hash table and the guest_rpte
1238 * values in the revmap array.
1239 *
1240 * On writes, each HPTE written is considered in turn, and if it
1241 * is valid, it is written to the HPT as if an H_ENTER with the
1242 * exact flag set was done. When the invalid count is non-zero
1243 * in the header written to the stream, the kernel will make
1244 * sure that that many HPTEs are invalid, and invalidate them
1245 * if not.
1246 */
1247
1248 struct kvm_htab_ctx {
1249 unsigned long index;
1250 unsigned long flags;
1251 struct kvm *kvm;
1252 int first_pass;
1253 };
1254
1255 #define HPTE_SIZE (2 * sizeof(unsigned long))
1256
1257 /*
1258 * Returns 1 if this HPT entry has been modified or has pending
1259 * R/C bit changes.
1260 */
1261 static int hpte_dirty(struct revmap_entry *revp, unsigned long *hptp)
1262 {
1263 unsigned long rcbits_unset;
1264
1265 if (revp->guest_rpte & HPTE_GR_MODIFIED)
1266 return 1;
1267
1268 /* Also need to consider changes in reference and changed bits */
1269 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1270 if ((hptp[0] & HPTE_V_VALID) && (hptp[1] & rcbits_unset))
1271 return 1;
1272
1273 return 0;
1274 }
1275
1276 static long record_hpte(unsigned long flags, unsigned long *hptp,
1277 unsigned long *hpte, struct revmap_entry *revp,
1278 int want_valid, int first_pass)
1279 {
1280 unsigned long v, r;
1281 unsigned long rcbits_unset;
1282 int ok = 1;
1283 int valid, dirty;
1284
1285 /* Unmodified entries are uninteresting except on the first pass */
1286 dirty = hpte_dirty(revp, hptp);
1287 if (!first_pass && !dirty)
1288 return 0;
1289
1290 valid = 0;
1291 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1292 valid = 1;
1293 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1294 !(hptp[0] & HPTE_V_BOLTED))
1295 valid = 0;
1296 }
1297 if (valid != want_valid)
1298 return 0;
1299
1300 v = r = 0;
1301 if (valid || dirty) {
1302 /* lock the HPTE so it's stable and read it */
1303 preempt_disable();
1304 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1305 cpu_relax();
1306 v = hptp[0];
1307
1308 /* re-evaluate valid and dirty from synchronized HPTE value */
1309 valid = !!(v & HPTE_V_VALID);
1310 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1311
1312 /* Harvest R and C into guest view if necessary */
1313 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1314 if (valid && (rcbits_unset & hptp[1])) {
1315 revp->guest_rpte |= (hptp[1] & (HPTE_R_R | HPTE_R_C)) |
1316 HPTE_GR_MODIFIED;
1317 dirty = 1;
1318 }
1319
1320 if (v & HPTE_V_ABSENT) {
1321 v &= ~HPTE_V_ABSENT;
1322 v |= HPTE_V_VALID;
1323 valid = 1;
1324 }
1325 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1326 valid = 0;
1327
1328 r = revp->guest_rpte;
1329 /* only clear modified if this is the right sort of entry */
1330 if (valid == want_valid && dirty) {
1331 r &= ~HPTE_GR_MODIFIED;
1332 revp->guest_rpte = r;
1333 }
1334 asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
1335 hptp[0] &= ~HPTE_V_HVLOCK;
1336 preempt_enable();
1337 if (!(valid == want_valid && (first_pass || dirty)))
1338 ok = 0;
1339 }
1340 hpte[0] = v;
1341 hpte[1] = r;
1342 return ok;
1343 }
1344
1345 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1346 size_t count, loff_t *ppos)
1347 {
1348 struct kvm_htab_ctx *ctx = file->private_data;
1349 struct kvm *kvm = ctx->kvm;
1350 struct kvm_get_htab_header hdr;
1351 unsigned long *hptp;
1352 struct revmap_entry *revp;
1353 unsigned long i, nb, nw;
1354 unsigned long __user *lbuf;
1355 struct kvm_get_htab_header __user *hptr;
1356 unsigned long flags;
1357 int first_pass;
1358 unsigned long hpte[2];
1359
1360 if (!access_ok(VERIFY_WRITE, buf, count))
1361 return -EFAULT;
1362
1363 first_pass = ctx->first_pass;
1364 flags = ctx->flags;
1365
1366 i = ctx->index;
1367 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1368 revp = kvm->arch.revmap + i;
1369 lbuf = (unsigned long __user *)buf;
1370
1371 nb = 0;
1372 while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1373 /* Initialize header */
1374 hptr = (struct kvm_get_htab_header __user *)buf;
1375 hdr.n_valid = 0;
1376 hdr.n_invalid = 0;
1377 nw = nb;
1378 nb += sizeof(hdr);
1379 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1380
1381 /* Skip uninteresting entries, i.e. clean on not-first pass */
1382 if (!first_pass) {
1383 while (i < kvm->arch.hpt_npte &&
1384 !hpte_dirty(revp, hptp)) {
1385 ++i;
1386 hptp += 2;
1387 ++revp;
1388 }
1389 }
1390 hdr.index = i;
1391
1392 /* Grab a series of valid entries */
1393 while (i < kvm->arch.hpt_npte &&
1394 hdr.n_valid < 0xffff &&
1395 nb + HPTE_SIZE < count &&
1396 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1397 /* valid entry, write it out */
1398 ++hdr.n_valid;
1399 if (__put_user(hpte[0], lbuf) ||
1400 __put_user(hpte[1], lbuf + 1))
1401 return -EFAULT;
1402 nb += HPTE_SIZE;
1403 lbuf += 2;
1404 ++i;
1405 hptp += 2;
1406 ++revp;
1407 }
1408 /* Now skip invalid entries while we can */
1409 while (i < kvm->arch.hpt_npte &&
1410 hdr.n_invalid < 0xffff &&
1411 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1412 /* found an invalid entry */
1413 ++hdr.n_invalid;
1414 ++i;
1415 hptp += 2;
1416 ++revp;
1417 }
1418
1419 if (hdr.n_valid || hdr.n_invalid) {
1420 /* write back the header */
1421 if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1422 return -EFAULT;
1423 nw = nb;
1424 buf = (char __user *)lbuf;
1425 } else {
1426 nb = nw;
1427 }
1428
1429 /* Check if we've wrapped around the hash table */
1430 if (i >= kvm->arch.hpt_npte) {
1431 i = 0;
1432 ctx->first_pass = 0;
1433 break;
1434 }
1435 }
1436
1437 ctx->index = i;
1438
1439 return nb;
1440 }
1441
1442 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1443 size_t count, loff_t *ppos)
1444 {
1445 struct kvm_htab_ctx *ctx = file->private_data;
1446 struct kvm *kvm = ctx->kvm;
1447 struct kvm_get_htab_header hdr;
1448 unsigned long i, j;
1449 unsigned long v, r;
1450 unsigned long __user *lbuf;
1451 unsigned long *hptp;
1452 unsigned long tmp[2];
1453 ssize_t nb;
1454 long int err, ret;
1455 int rma_setup;
1456
1457 if (!access_ok(VERIFY_READ, buf, count))
1458 return -EFAULT;
1459
1460 /* lock out vcpus from running while we're doing this */
1461 mutex_lock(&kvm->lock);
1462 rma_setup = kvm->arch.rma_setup_done;
1463 if (rma_setup) {
1464 kvm->arch.rma_setup_done = 0; /* temporarily */
1465 /* order rma_setup_done vs. vcpus_running */
1466 smp_mb();
1467 if (atomic_read(&kvm->arch.vcpus_running)) {
1468 kvm->arch.rma_setup_done = 1;
1469 mutex_unlock(&kvm->lock);
1470 return -EBUSY;
1471 }
1472 }
1473
1474 err = 0;
1475 for (nb = 0; nb + sizeof(hdr) <= count; ) {
1476 err = -EFAULT;
1477 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1478 break;
1479
1480 err = 0;
1481 if (nb + hdr.n_valid * HPTE_SIZE > count)
1482 break;
1483
1484 nb += sizeof(hdr);
1485 buf += sizeof(hdr);
1486
1487 err = -EINVAL;
1488 i = hdr.index;
1489 if (i >= kvm->arch.hpt_npte ||
1490 i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
1491 break;
1492
1493 hptp = (unsigned long *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
1494 lbuf = (unsigned long __user *)buf;
1495 for (j = 0; j < hdr.n_valid; ++j) {
1496 err = -EFAULT;
1497 if (__get_user(v, lbuf) || __get_user(r, lbuf + 1))
1498 goto out;
1499 err = -EINVAL;
1500 if (!(v & HPTE_V_VALID))
1501 goto out;
1502 lbuf += 2;
1503 nb += HPTE_SIZE;
1504
1505 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1506 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1507 err = -EIO;
1508 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1509 tmp);
1510 if (ret != H_SUCCESS) {
1511 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1512 "r=%lx\n", ret, i, v, r);
1513 goto out;
1514 }
1515 if (!rma_setup && is_vrma_hpte(v)) {
1516 unsigned long psize = hpte_page_size(v, r);
1517 unsigned long senc = slb_pgsize_encoding(psize);
1518 unsigned long lpcr;
1519
1520 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1521 (VRMA_VSID << SLB_VSID_SHIFT_1T);
1522 lpcr = senc << (LPCR_VRMASD_SH - 4);
1523 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1524 rma_setup = 1;
1525 }
1526 ++i;
1527 hptp += 2;
1528 }
1529
1530 for (j = 0; j < hdr.n_invalid; ++j) {
1531 if (hptp[0] & (HPTE_V_VALID | HPTE_V_ABSENT))
1532 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1533 ++i;
1534 hptp += 2;
1535 }
1536 err = 0;
1537 }
1538
1539 out:
1540 /* Order HPTE updates vs. rma_setup_done */
1541 smp_wmb();
1542 kvm->arch.rma_setup_done = rma_setup;
1543 mutex_unlock(&kvm->lock);
1544
1545 if (err)
1546 return err;
1547 return nb;
1548 }
1549
1550 static int kvm_htab_release(struct inode *inode, struct file *filp)
1551 {
1552 struct kvm_htab_ctx *ctx = filp->private_data;
1553
1554 filp->private_data = NULL;
1555 if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1556 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1557 kvm_put_kvm(ctx->kvm);
1558 kfree(ctx);
1559 return 0;
1560 }
1561
1562 static const struct file_operations kvm_htab_fops = {
1563 .read = kvm_htab_read,
1564 .write = kvm_htab_write,
1565 .llseek = default_llseek,
1566 .release = kvm_htab_release,
1567 };
1568
1569 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1570 {
1571 int ret;
1572 struct kvm_htab_ctx *ctx;
1573 int rwflag;
1574
1575 /* reject flags we don't recognize */
1576 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1577 return -EINVAL;
1578 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1579 if (!ctx)
1580 return -ENOMEM;
1581 kvm_get_kvm(kvm);
1582 ctx->kvm = kvm;
1583 ctx->index = ghf->start_index;
1584 ctx->flags = ghf->flags;
1585 ctx->first_pass = 1;
1586
1587 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1588 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1589 if (ret < 0) {
1590 kvm_put_kvm(kvm);
1591 return ret;
1592 }
1593
1594 if (rwflag == O_RDONLY) {
1595 mutex_lock(&kvm->slots_lock);
1596 atomic_inc(&kvm->arch.hpte_mod_interest);
1597 /* make sure kvmppc_do_h_enter etc. see the increment */
1598 synchronize_srcu_expedited(&kvm->srcu);
1599 mutex_unlock(&kvm->slots_lock);
1600 }
1601
1602 return ret;
1603 }
1604
1605 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
1606 {
1607 struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
1608
1609 if (cpu_has_feature(CPU_FTR_ARCH_206))
1610 vcpu->arch.slb_nr = 32; /* POWER7 */
1611 else
1612 vcpu->arch.slb_nr = 64;
1613
1614 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
1615 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
1616
1617 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
1618 }
Linux with added FPC-III support