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 #include <linux/debugfs.h>
31
32 #include <asm/tlbflush.h>
33 #include <asm/kvm_ppc.h>
34 #include <asm/kvm_book3s.h>
35 #include <asm/book3s/64/mmu-hash.h>
36 #include <asm/hvcall.h>
37 #include <asm/synch.h>
38 #include <asm/ppc-opcode.h>
39 #include <asm/cputable.h>
40 #include <asm/pte-walk.h>
41
42 #include "trace_hv.h"
43
44 //#define DEBUG_RESIZE_HPT 1
45
46 #ifdef DEBUG_RESIZE_HPT
47 #define resize_hpt_debug(resize, ...) \
48 do { \
49 printk(KERN_DEBUG "RESIZE HPT %p: ", resize); \
50 printk(__VA_ARGS__); \
51 } while (0)
52 #else
53 #define resize_hpt_debug(resize, ...) \
54 do { } while (0)
55 #endif
56
57 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
58 long pte_index, unsigned long pteh,
59 unsigned long ptel, unsigned long *pte_idx_ret);
60
61 struct kvm_resize_hpt {
62 /* These fields read-only after init */
63 struct kvm *kvm;
64 struct work_struct work;
65 u32 order;
66
67 /* These fields protected by kvm->lock */
68
69 /* Possible values and their usage:
70 * <0 an error occurred during allocation,
71 * -EBUSY allocation is in the progress,
72 * 0 allocation made successfuly.
73 */
74 int error;
75
76 /* Private to the work thread, until error != -EBUSY,
77 * then protected by kvm->lock.
78 */
79 struct kvm_hpt_info hpt;
80 };
81
82 static void kvmppc_rmap_reset(struct kvm *kvm);
83
kvmppc_allocate_hpt(struct kvm_hpt_info * info,u32 order)84 int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order)
85 {
86 unsigned long hpt = 0;
87 int cma = 0;
88 struct page *page = NULL;
89 struct revmap_entry *rev;
90 unsigned long npte;
91
92 if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER))
93 return -EINVAL;
94
95 page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT));
96 if (page) {
97 hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
98 memset((void *)hpt, 0, (1ul << order));
99 cma = 1;
100 }
101
102 if (!hpt)
103 hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL
104 |__GFP_NOWARN, order - PAGE_SHIFT);
105
106 if (!hpt)
107 return -ENOMEM;
108
109 /* HPTEs are 2**4 bytes long */
110 npte = 1ul << (order - 4);
111
112 /* Allocate reverse map array */
113 rev = vmalloc(sizeof(struct revmap_entry) * npte);
114 if (!rev) {
115 pr_err("kvmppc_allocate_hpt: Couldn't alloc reverse map array\n");
116 if (cma)
117 kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT));
118 else
119 free_pages(hpt, order - PAGE_SHIFT);
120 return -ENOMEM;
121 }
122
123 info->order = order;
124 info->virt = hpt;
125 info->cma = cma;
126 info->rev = rev;
127
128 return 0;
129 }
130
kvmppc_set_hpt(struct kvm * kvm,struct kvm_hpt_info * info)131 void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info)
132 {
133 atomic64_set(&kvm->arch.mmio_update, 0);
134 kvm->arch.hpt = *info;
135 kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18);
136
137 pr_debug("KVM guest htab at %lx (order %ld), LPID %x\n",
138 info->virt, (long)info->order, kvm->arch.lpid);
139 }
140
kvmppc_alloc_reset_hpt(struct kvm * kvm,int order)141 long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
142 {
143 long err = -EBUSY;
144 struct kvm_hpt_info info;
145
146 if (kvm_is_radix(kvm))
147 return -EINVAL;
148
149 mutex_lock(&kvm->lock);
150 if (kvm->arch.hpte_setup_done) {
151 kvm->arch.hpte_setup_done = 0;
152 /* order hpte_setup_done vs. vcpus_running */
153 smp_mb();
154 if (atomic_read(&kvm->arch.vcpus_running)) {
155 kvm->arch.hpte_setup_done = 1;
156 goto out;
157 }
158 }
159 if (kvm->arch.hpt.order == order) {
160 /* We already have a suitable HPT */
161
162 /* Set the entire HPT to 0, i.e. invalid HPTEs */
163 memset((void *)kvm->arch.hpt.virt, 0, 1ul << order);
164 /*
165 * Reset all the reverse-mapping chains for all memslots
166 */
167 kvmppc_rmap_reset(kvm);
168 err = 0;
169 goto out;
170 }
171
172 if (kvm->arch.hpt.virt) {
173 kvmppc_free_hpt(&kvm->arch.hpt);
174 kvmppc_rmap_reset(kvm);
175 }
176
177 err = kvmppc_allocate_hpt(&info, order);
178 if (err < 0)
179 goto out;
180 kvmppc_set_hpt(kvm, &info);
181
182 out:
183 if (err == 0)
184 /* Ensure that each vcpu will flush its TLB on next entry. */
185 cpumask_setall(&kvm->arch.need_tlb_flush);
186
187 mutex_unlock(&kvm->lock);
188 return err;
189 }
190
kvmppc_free_hpt(struct kvm_hpt_info * info)191 void kvmppc_free_hpt(struct kvm_hpt_info *info)
192 {
193 vfree(info->rev);
194 if (info->cma)
195 kvm_free_hpt_cma(virt_to_page(info->virt),
196 1 << (info->order - PAGE_SHIFT));
197 else if (info->virt)
198 free_pages(info->virt, info->order - PAGE_SHIFT);
199 info->virt = 0;
200 info->order = 0;
201 }
202
203 /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
hpte0_pgsize_encoding(unsigned long pgsize)204 static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
205 {
206 return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
207 }
208
209 /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
hpte1_pgsize_encoding(unsigned long pgsize)210 static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
211 {
212 return (pgsize == 0x10000) ? 0x1000 : 0;
213 }
214
kvmppc_map_vrma(struct kvm_vcpu * vcpu,struct kvm_memory_slot * memslot,unsigned long porder)215 void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
216 unsigned long porder)
217 {
218 unsigned long i;
219 unsigned long npages;
220 unsigned long hp_v, hp_r;
221 unsigned long addr, hash;
222 unsigned long psize;
223 unsigned long hp0, hp1;
224 unsigned long idx_ret;
225 long ret;
226 struct kvm *kvm = vcpu->kvm;
227
228 psize = 1ul << porder;
229 npages = memslot->npages >> (porder - PAGE_SHIFT);
230
231 /* VRMA can't be > 1TB */
232 if (npages > 1ul << (40 - porder))
233 npages = 1ul << (40 - porder);
234 /* Can't use more than 1 HPTE per HPTEG */
235 if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
236 npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
237
238 hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
239 HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
240 hp1 = hpte1_pgsize_encoding(psize) |
241 HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
242
243 for (i = 0; i < npages; ++i) {
244 addr = i << porder;
245 /* can't use hpt_hash since va > 64 bits */
246 hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
247 & kvmppc_hpt_mask(&kvm->arch.hpt);
248 /*
249 * We assume that the hash table is empty and no
250 * vcpus are using it at this stage. Since we create
251 * at most one HPTE per HPTEG, we just assume entry 7
252 * is available and use it.
253 */
254 hash = (hash << 3) + 7;
255 hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
256 hp_r = hp1 | addr;
257 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
258 &idx_ret);
259 if (ret != H_SUCCESS) {
260 pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
261 addr, ret);
262 break;
263 }
264 }
265 }
266
kvmppc_mmu_hv_init(void)267 int kvmppc_mmu_hv_init(void)
268 {
269 unsigned long host_lpid, rsvd_lpid;
270
271 if (!cpu_has_feature(CPU_FTR_HVMODE))
272 return -EINVAL;
273
274 /* POWER7 has 10-bit LPIDs (12-bit in POWER8) */
275 host_lpid = mfspr(SPRN_LPID);
276 rsvd_lpid = LPID_RSVD;
277
278 kvmppc_init_lpid(rsvd_lpid + 1);
279
280 kvmppc_claim_lpid(host_lpid);
281 /* rsvd_lpid is reserved for use in partition switching */
282 kvmppc_claim_lpid(rsvd_lpid);
283
284 return 0;
285 }
286
kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu * vcpu)287 static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
288 {
289 unsigned long msr = vcpu->arch.intr_msr;
290
291 /* If transactional, change to suspend mode on IRQ delivery */
292 if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
293 msr |= MSR_TS_S;
294 else
295 msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
296 kvmppc_set_msr(vcpu, msr);
297 }
298
kvmppc_virtmode_do_h_enter(struct kvm * kvm,unsigned long flags,long pte_index,unsigned long pteh,unsigned long ptel,unsigned long * pte_idx_ret)299 static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
300 long pte_index, unsigned long pteh,
301 unsigned long ptel, unsigned long *pte_idx_ret)
302 {
303 long ret;
304
305 /* Protect linux PTE lookup from page table destruction */
306 rcu_read_lock_sched(); /* this disables preemption too */
307 ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
308 current->mm->pgd, false, pte_idx_ret);
309 rcu_read_unlock_sched();
310 if (ret == H_TOO_HARD) {
311 /* this can't happen */
312 pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
313 ret = H_RESOURCE; /* or something */
314 }
315 return ret;
316
317 }
318
kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu * vcpu,gva_t eaddr)319 static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
320 gva_t eaddr)
321 {
322 u64 mask;
323 int i;
324
325 for (i = 0; i < vcpu->arch.slb_nr; i++) {
326 if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
327 continue;
328
329 if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
330 mask = ESID_MASK_1T;
331 else
332 mask = ESID_MASK;
333
334 if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
335 return &vcpu->arch.slb[i];
336 }
337 return NULL;
338 }
339
kvmppc_mmu_get_real_addr(unsigned long v,unsigned long r,unsigned long ea)340 static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
341 unsigned long ea)
342 {
343 unsigned long ra_mask;
344
345 ra_mask = hpte_page_size(v, r) - 1;
346 return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
347 }
348
kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,bool data,bool iswrite)349 static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
350 struct kvmppc_pte *gpte, bool data, bool iswrite)
351 {
352 struct kvm *kvm = vcpu->kvm;
353 struct kvmppc_slb *slbe;
354 unsigned long slb_v;
355 unsigned long pp, key;
356 unsigned long v, orig_v, gr;
357 __be64 *hptep;
358 long int index;
359 int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
360
361 /* Get SLB entry */
362 if (virtmode) {
363 slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
364 if (!slbe)
365 return -EINVAL;
366 slb_v = slbe->origv;
367 } else {
368 /* real mode access */
369 slb_v = vcpu->kvm->arch.vrma_slb_v;
370 }
371
372 preempt_disable();
373 /* Find the HPTE in the hash table */
374 index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
375 HPTE_V_VALID | HPTE_V_ABSENT);
376 if (index < 0) {
377 preempt_enable();
378 return -ENOENT;
379 }
380 hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
381 v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
382 if (cpu_has_feature(CPU_FTR_ARCH_300))
383 v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1]));
384 gr = kvm->arch.hpt.rev[index].guest_rpte;
385
386 unlock_hpte(hptep, orig_v);
387 preempt_enable();
388
389 gpte->eaddr = eaddr;
390 gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
391
392 /* Get PP bits and key for permission check */
393 pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
394 key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
395 key &= slb_v;
396
397 /* Calculate permissions */
398 gpte->may_read = hpte_read_permission(pp, key);
399 gpte->may_write = hpte_write_permission(pp, key);
400 gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
401
402 /* Storage key permission check for POWER7 */
403 if (data && virtmode) {
404 int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
405 if (amrfield & 1)
406 gpte->may_read = 0;
407 if (amrfield & 2)
408 gpte->may_write = 0;
409 }
410
411 /* Get the guest physical address */
412 gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
413 return 0;
414 }
415
416 /*
417 * Quick test for whether an instruction is a load or a store.
418 * If the instruction is a load or a store, then this will indicate
419 * which it is, at least on server processors. (Embedded processors
420 * have some external PID instructions that don't follow the rule
421 * embodied here.) If the instruction isn't a load or store, then
422 * this doesn't return anything useful.
423 */
instruction_is_store(unsigned int instr)424 static int instruction_is_store(unsigned int instr)
425 {
426 unsigned int mask;
427
428 mask = 0x10000000;
429 if ((instr & 0xfc000000) == 0x7c000000)
430 mask = 0x100; /* major opcode 31 */
431 return (instr & mask) != 0;
432 }
433
kvmppc_hv_emulate_mmio(struct kvm_run * run,struct kvm_vcpu * vcpu,unsigned long gpa,gva_t ea,int is_store)434 int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
435 unsigned long gpa, gva_t ea, int is_store)
436 {
437 u32 last_inst;
438
439 /*
440 * If we fail, we just return to the guest and try executing it again.
441 */
442 if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
443 EMULATE_DONE)
444 return RESUME_GUEST;
445
446 /*
447 * WARNING: We do not know for sure whether the instruction we just
448 * read from memory is the same that caused the fault in the first
449 * place. If the instruction we read is neither an load or a store,
450 * then it can't access memory, so we don't need to worry about
451 * enforcing access permissions. So, assuming it is a load or
452 * store, we just check that its direction (load or store) is
453 * consistent with the original fault, since that's what we
454 * checked the access permissions against. If there is a mismatch
455 * we just return and retry the instruction.
456 */
457
458 if (instruction_is_store(last_inst) != !!is_store)
459 return RESUME_GUEST;
460
461 /*
462 * Emulated accesses are emulated by looking at the hash for
463 * translation once, then performing the access later. The
464 * translation could be invalidated in the meantime in which
465 * point performing the subsequent memory access on the old
466 * physical address could possibly be a security hole for the
467 * guest (but not the host).
468 *
469 * This is less of an issue for MMIO stores since they aren't
470 * globally visible. It could be an issue for MMIO loads to
471 * a certain extent but we'll ignore it for now.
472 */
473
474 vcpu->arch.paddr_accessed = gpa;
475 vcpu->arch.vaddr_accessed = ea;
476 return kvmppc_emulate_mmio(run, vcpu);
477 }
478
kvmppc_book3s_hv_page_fault(struct kvm_run * run,struct kvm_vcpu * vcpu,unsigned long ea,unsigned long dsisr)479 int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
480 unsigned long ea, unsigned long dsisr)
481 {
482 struct kvm *kvm = vcpu->kvm;
483 unsigned long hpte[3], r;
484 unsigned long hnow_v, hnow_r;
485 __be64 *hptep;
486 unsigned long mmu_seq, psize, pte_size;
487 unsigned long gpa_base, gfn_base;
488 unsigned long gpa, gfn, hva, pfn;
489 struct kvm_memory_slot *memslot;
490 unsigned long *rmap;
491 struct revmap_entry *rev;
492 struct page *page, *pages[1];
493 long index, ret, npages;
494 bool is_ci;
495 unsigned int writing, write_ok;
496 struct vm_area_struct *vma;
497 unsigned long rcbits;
498 long mmio_update;
499
500 if (kvm_is_radix(kvm))
501 return kvmppc_book3s_radix_page_fault(run, vcpu, ea, dsisr);
502
503 /*
504 * Real-mode code has already searched the HPT and found the
505 * entry we're interested in. Lock the entry and check that
506 * it hasn't changed. If it has, just return and re-execute the
507 * instruction.
508 */
509 if (ea != vcpu->arch.pgfault_addr)
510 return RESUME_GUEST;
511
512 if (vcpu->arch.pgfault_cache) {
513 mmio_update = atomic64_read(&kvm->arch.mmio_update);
514 if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) {
515 r = vcpu->arch.pgfault_cache->rpte;
516 psize = hpte_page_size(vcpu->arch.pgfault_hpte[0], r);
517 gpa_base = r & HPTE_R_RPN & ~(psize - 1);
518 gfn_base = gpa_base >> PAGE_SHIFT;
519 gpa = gpa_base | (ea & (psize - 1));
520 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
521 dsisr & DSISR_ISSTORE);
522 }
523 }
524 index = vcpu->arch.pgfault_index;
525 hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4));
526 rev = &kvm->arch.hpt.rev[index];
527 preempt_disable();
528 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
529 cpu_relax();
530 hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
531 hpte[1] = be64_to_cpu(hptep[1]);
532 hpte[2] = r = rev->guest_rpte;
533 unlock_hpte(hptep, hpte[0]);
534 preempt_enable();
535
536 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
537 hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]);
538 hpte[1] = hpte_new_to_old_r(hpte[1]);
539 }
540 if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
541 hpte[1] != vcpu->arch.pgfault_hpte[1])
542 return RESUME_GUEST;
543
544 /* Translate the logical address and get the page */
545 psize = hpte_page_size(hpte[0], 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 gfn = gpa >> PAGE_SHIFT;
550 memslot = gfn_to_memslot(kvm, gfn);
551
552 trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr);
553
554 /* No memslot means it's an emulated MMIO region */
555 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
556 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
557 dsisr & DSISR_ISSTORE);
558
559 /*
560 * This should never happen, because of the slot_is_aligned()
561 * check in kvmppc_do_h_enter().
562 */
563 if (gfn_base < memslot->base_gfn)
564 return -EFAULT;
565
566 /* used to check for invalidations in progress */
567 mmu_seq = kvm->mmu_notifier_seq;
568 smp_rmb();
569
570 ret = -EFAULT;
571 is_ci = false;
572 pfn = 0;
573 page = NULL;
574 pte_size = PAGE_SIZE;
575 writing = (dsisr & DSISR_ISSTORE) != 0;
576 /* If writing != 0, then the HPTE must allow writing, if we get here */
577 write_ok = writing;
578 hva = gfn_to_hva_memslot(memslot, gfn);
579 npages = get_user_pages_fast(hva, 1, writing, pages);
580 if (npages < 1) {
581 /* Check if it's an I/O mapping */
582 down_read(¤t->mm->mmap_sem);
583 vma = find_vma(current->mm, hva);
584 if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
585 (vma->vm_flags & VM_PFNMAP)) {
586 pfn = vma->vm_pgoff +
587 ((hva - vma->vm_start) >> PAGE_SHIFT);
588 pte_size = psize;
589 is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
590 write_ok = vma->vm_flags & VM_WRITE;
591 }
592 up_read(¤t->mm->mmap_sem);
593 if (!pfn)
594 goto out_put;
595 } else {
596 page = pages[0];
597 pfn = page_to_pfn(page);
598 if (PageHuge(page)) {
599 page = compound_head(page);
600 pte_size <<= compound_order(page);
601 }
602 /* if the guest wants write access, see if that is OK */
603 if (!writing && hpte_is_writable(r)) {
604 pte_t *ptep, pte;
605 unsigned long flags;
606 /*
607 * We need to protect against page table destruction
608 * hugepage split and collapse.
609 */
610 local_irq_save(flags);
611 ptep = find_current_mm_pte(current->mm->pgd,
612 hva, NULL, NULL);
613 if (ptep) {
614 pte = kvmppc_read_update_linux_pte(ptep, 1);
615 if (__pte_write(pte))
616 write_ok = 1;
617 }
618 local_irq_restore(flags);
619 }
620 }
621
622 if (psize > pte_size)
623 goto out_put;
624
625 /* Check WIMG vs. the actual page we're accessing */
626 if (!hpte_cache_flags_ok(r, is_ci)) {
627 if (is_ci)
628 goto out_put;
629 /*
630 * Allow guest to map emulated device memory as
631 * uncacheable, but actually make it cacheable.
632 */
633 r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
634 }
635
636 /*
637 * Set the HPTE to point to pfn.
638 * Since the pfn is at PAGE_SIZE granularity, make sure we
639 * don't mask out lower-order bits if psize < PAGE_SIZE.
640 */
641 if (psize < PAGE_SIZE)
642 psize = PAGE_SIZE;
643 r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) |
644 ((pfn << PAGE_SHIFT) & ~(psize - 1));
645 if (hpte_is_writable(r) && !write_ok)
646 r = hpte_make_readonly(r);
647 ret = RESUME_GUEST;
648 preempt_disable();
649 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
650 cpu_relax();
651 hnow_v = be64_to_cpu(hptep[0]);
652 hnow_r = be64_to_cpu(hptep[1]);
653 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
654 hnow_v = hpte_new_to_old_v(hnow_v, hnow_r);
655 hnow_r = hpte_new_to_old_r(hnow_r);
656 }
657
658 /*
659 * If the HPT is being resized, don't update the HPTE,
660 * instead let the guest retry after the resize operation is complete.
661 * The synchronization for hpte_setup_done test vs. set is provided
662 * by the HPTE lock.
663 */
664 if (!kvm->arch.hpte_setup_done)
665 goto out_unlock;
666
667 if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] ||
668 rev->guest_rpte != hpte[2])
669 /* HPTE has been changed under us; let the guest retry */
670 goto out_unlock;
671 hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
672
673 /* Always put the HPTE in the rmap chain for the page base address */
674 rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
675 lock_rmap(rmap);
676
677 /* Check if we might have been invalidated; let the guest retry if so */
678 ret = RESUME_GUEST;
679 if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
680 unlock_rmap(rmap);
681 goto out_unlock;
682 }
683
684 /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
685 rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
686 r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
687
688 if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
689 /* HPTE was previously valid, so we need to invalidate it */
690 unlock_rmap(rmap);
691 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
692 kvmppc_invalidate_hpte(kvm, hptep, index);
693 /* don't lose previous R and C bits */
694 r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
695 } else {
696 kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
697 }
698
699 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
700 r = hpte_old_to_new_r(hpte[0], r);
701 hpte[0] = hpte_old_to_new_v(hpte[0]);
702 }
703 hptep[1] = cpu_to_be64(r);
704 eieio();
705 __unlock_hpte(hptep, hpte[0]);
706 asm volatile("ptesync" : : : "memory");
707 preempt_enable();
708 if (page && hpte_is_writable(r))
709 SetPageDirty(page);
710
711 out_put:
712 trace_kvm_page_fault_exit(vcpu, hpte, ret);
713
714 if (page) {
715 /*
716 * We drop pages[0] here, not page because page might
717 * have been set to the head page of a compound, but
718 * we have to drop the reference on the correct tail
719 * page to match the get inside gup()
720 */
721 put_page(pages[0]);
722 }
723 return ret;
724
725 out_unlock:
726 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
727 preempt_enable();
728 goto out_put;
729 }
730
kvmppc_rmap_reset(struct kvm * kvm)731 static void kvmppc_rmap_reset(struct kvm *kvm)
732 {
733 struct kvm_memslots *slots;
734 struct kvm_memory_slot *memslot;
735 int srcu_idx;
736
737 srcu_idx = srcu_read_lock(&kvm->srcu);
738 slots = kvm_memslots(kvm);
739 kvm_for_each_memslot(memslot, slots) {
740 /*
741 * This assumes it is acceptable to lose reference and
742 * change bits across a reset.
743 */
744 memset(memslot->arch.rmap, 0,
745 memslot->npages * sizeof(*memslot->arch.rmap));
746 }
747 srcu_read_unlock(&kvm->srcu, srcu_idx);
748 }
749
750 typedef int (*hva_handler_fn)(struct kvm *kvm, struct kvm_memory_slot *memslot,
751 unsigned long gfn);
752
kvm_handle_hva_range(struct kvm * kvm,unsigned long start,unsigned long end,hva_handler_fn handler)753 static int kvm_handle_hva_range(struct kvm *kvm,
754 unsigned long start,
755 unsigned long end,
756 hva_handler_fn handler)
757 {
758 int ret;
759 int retval = 0;
760 struct kvm_memslots *slots;
761 struct kvm_memory_slot *memslot;
762
763 slots = kvm_memslots(kvm);
764 kvm_for_each_memslot(memslot, slots) {
765 unsigned long hva_start, hva_end;
766 gfn_t gfn, gfn_end;
767
768 hva_start = max(start, memslot->userspace_addr);
769 hva_end = min(end, memslot->userspace_addr +
770 (memslot->npages << PAGE_SHIFT));
771 if (hva_start >= hva_end)
772 continue;
773 /*
774 * {gfn(page) | page intersects with [hva_start, hva_end)} =
775 * {gfn, gfn+1, ..., gfn_end-1}.
776 */
777 gfn = hva_to_gfn_memslot(hva_start, memslot);
778 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
779
780 for (; gfn < gfn_end; ++gfn) {
781 ret = handler(kvm, memslot, gfn);
782 retval |= ret;
783 }
784 }
785
786 return retval;
787 }
788
kvm_handle_hva(struct kvm * kvm,unsigned long hva,hva_handler_fn handler)789 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
790 hva_handler_fn handler)
791 {
792 return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
793 }
794
795 /* Must be called with both HPTE and rmap locked */
kvmppc_unmap_hpte(struct kvm * kvm,unsigned long i,unsigned long * rmapp,unsigned long gfn)796 static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
797 unsigned long *rmapp, unsigned long gfn)
798 {
799 __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
800 struct revmap_entry *rev = kvm->arch.hpt.rev;
801 unsigned long j, h;
802 unsigned long ptel, psize, rcbits;
803
804 j = rev[i].forw;
805 if (j == i) {
806 /* chain is now empty */
807 *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
808 } else {
809 /* remove i from chain */
810 h = rev[i].back;
811 rev[h].forw = j;
812 rev[j].back = h;
813 rev[i].forw = rev[i].back = i;
814 *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
815 }
816
817 /* Now check and modify the HPTE */
818 ptel = rev[i].guest_rpte;
819 psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
820 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
821 hpte_rpn(ptel, psize) == gfn) {
822 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
823 kvmppc_invalidate_hpte(kvm, hptep, i);
824 hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
825 /* Harvest R and C */
826 rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
827 *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
828 if (rcbits & HPTE_R_C)
829 kvmppc_update_rmap_change(rmapp, psize);
830 if (rcbits & ~rev[i].guest_rpte) {
831 rev[i].guest_rpte = ptel | rcbits;
832 note_hpte_modification(kvm, &rev[i]);
833 }
834 }
835 }
836
kvm_unmap_rmapp(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)837 static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
838 unsigned long gfn)
839 {
840 unsigned long i;
841 __be64 *hptep;
842 unsigned long *rmapp;
843
844 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
845 for (;;) {
846 lock_rmap(rmapp);
847 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
848 unlock_rmap(rmapp);
849 break;
850 }
851
852 /*
853 * To avoid an ABBA deadlock with the HPTE lock bit,
854 * we can't spin on the HPTE lock while holding the
855 * rmap chain lock.
856 */
857 i = *rmapp & KVMPPC_RMAP_INDEX;
858 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
859 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
860 /* unlock rmap before spinning on the HPTE lock */
861 unlock_rmap(rmapp);
862 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
863 cpu_relax();
864 continue;
865 }
866
867 kvmppc_unmap_hpte(kvm, i, rmapp, gfn);
868 unlock_rmap(rmapp);
869 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
870 }
871 return 0;
872 }
873
kvm_unmap_hva_hv(struct kvm * kvm,unsigned long hva)874 int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
875 {
876 hva_handler_fn handler;
877
878 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
879 kvm_handle_hva(kvm, hva, handler);
880 return 0;
881 }
882
kvm_unmap_hva_range_hv(struct kvm * kvm,unsigned long start,unsigned long end)883 int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
884 {
885 hva_handler_fn handler;
886
887 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
888 kvm_handle_hva_range(kvm, start, end, handler);
889 return 0;
890 }
891
kvmppc_core_flush_memslot_hv(struct kvm * kvm,struct kvm_memory_slot * memslot)892 void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
893 struct kvm_memory_slot *memslot)
894 {
895 unsigned long gfn;
896 unsigned long n;
897 unsigned long *rmapp;
898
899 gfn = memslot->base_gfn;
900 rmapp = memslot->arch.rmap;
901 for (n = memslot->npages; n; --n, ++gfn) {
902 if (kvm_is_radix(kvm)) {
903 kvm_unmap_radix(kvm, memslot, gfn);
904 continue;
905 }
906 /*
907 * Testing the present bit without locking is OK because
908 * the memslot has been marked invalid already, and hence
909 * no new HPTEs referencing this page can be created,
910 * thus the present bit can't go from 0 to 1.
911 */
912 if (*rmapp & KVMPPC_RMAP_PRESENT)
913 kvm_unmap_rmapp(kvm, memslot, gfn);
914 ++rmapp;
915 }
916 }
917
kvm_age_rmapp(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)918 static int kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
919 unsigned long gfn)
920 {
921 struct revmap_entry *rev = kvm->arch.hpt.rev;
922 unsigned long head, i, j;
923 __be64 *hptep;
924 int ret = 0;
925 unsigned long *rmapp;
926
927 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
928 retry:
929 lock_rmap(rmapp);
930 if (*rmapp & KVMPPC_RMAP_REFERENCED) {
931 *rmapp &= ~KVMPPC_RMAP_REFERENCED;
932 ret = 1;
933 }
934 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
935 unlock_rmap(rmapp);
936 return ret;
937 }
938
939 i = head = *rmapp & KVMPPC_RMAP_INDEX;
940 do {
941 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
942 j = rev[i].forw;
943
944 /* If this HPTE isn't referenced, ignore it */
945 if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
946 continue;
947
948 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
949 /* unlock rmap before spinning on the HPTE lock */
950 unlock_rmap(rmapp);
951 while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
952 cpu_relax();
953 goto retry;
954 }
955
956 /* Now check and modify the HPTE */
957 if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
958 (be64_to_cpu(hptep[1]) & HPTE_R_R)) {
959 kvmppc_clear_ref_hpte(kvm, hptep, i);
960 if (!(rev[i].guest_rpte & HPTE_R_R)) {
961 rev[i].guest_rpte |= HPTE_R_R;
962 note_hpte_modification(kvm, &rev[i]);
963 }
964 ret = 1;
965 }
966 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
967 } while ((i = j) != head);
968
969 unlock_rmap(rmapp);
970 return ret;
971 }
972
kvm_age_hva_hv(struct kvm * kvm,unsigned long start,unsigned long end)973 int kvm_age_hva_hv(struct kvm *kvm, unsigned long start, unsigned long end)
974 {
975 hva_handler_fn handler;
976
977 handler = kvm_is_radix(kvm) ? kvm_age_radix : kvm_age_rmapp;
978 return kvm_handle_hva_range(kvm, start, end, handler);
979 }
980
kvm_test_age_rmapp(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)981 static int kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
982 unsigned long gfn)
983 {
984 struct revmap_entry *rev = kvm->arch.hpt.rev;
985 unsigned long head, i, j;
986 unsigned long *hp;
987 int ret = 1;
988 unsigned long *rmapp;
989
990 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
991 if (*rmapp & KVMPPC_RMAP_REFERENCED)
992 return 1;
993
994 lock_rmap(rmapp);
995 if (*rmapp & KVMPPC_RMAP_REFERENCED)
996 goto out;
997
998 if (*rmapp & KVMPPC_RMAP_PRESENT) {
999 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1000 do {
1001 hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4));
1002 j = rev[i].forw;
1003 if (be64_to_cpu(hp[1]) & HPTE_R_R)
1004 goto out;
1005 } while ((i = j) != head);
1006 }
1007 ret = 0;
1008
1009 out:
1010 unlock_rmap(rmapp);
1011 return ret;
1012 }
1013
kvm_test_age_hva_hv(struct kvm * kvm,unsigned long hva)1014 int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
1015 {
1016 hva_handler_fn handler;
1017
1018 handler = kvm_is_radix(kvm) ? kvm_test_age_radix : kvm_test_age_rmapp;
1019 return kvm_handle_hva(kvm, hva, handler);
1020 }
1021
kvm_set_spte_hva_hv(struct kvm * kvm,unsigned long hva,pte_t pte)1022 void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
1023 {
1024 hva_handler_fn handler;
1025
1026 handler = kvm_is_radix(kvm) ? kvm_unmap_radix : kvm_unmap_rmapp;
1027 kvm_handle_hva(kvm, hva, handler);
1028 }
1029
vcpus_running(struct kvm * kvm)1030 static int vcpus_running(struct kvm *kvm)
1031 {
1032 return atomic_read(&kvm->arch.vcpus_running) != 0;
1033 }
1034
1035 /*
1036 * Returns the number of system pages that are dirty.
1037 * This can be more than 1 if we find a huge-page HPTE.
1038 */
kvm_test_clear_dirty_npages(struct kvm * kvm,unsigned long * rmapp)1039 static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
1040 {
1041 struct revmap_entry *rev = kvm->arch.hpt.rev;
1042 unsigned long head, i, j;
1043 unsigned long n;
1044 unsigned long v, r;
1045 __be64 *hptep;
1046 int npages_dirty = 0;
1047
1048 retry:
1049 lock_rmap(rmapp);
1050 if (*rmapp & KVMPPC_RMAP_CHANGED) {
1051 long change_order = (*rmapp & KVMPPC_RMAP_CHG_ORDER)
1052 >> KVMPPC_RMAP_CHG_SHIFT;
1053 *rmapp &= ~(KVMPPC_RMAP_CHANGED | KVMPPC_RMAP_CHG_ORDER);
1054 npages_dirty = 1;
1055 if (change_order > PAGE_SHIFT)
1056 npages_dirty = 1ul << (change_order - PAGE_SHIFT);
1057 }
1058 if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
1059 unlock_rmap(rmapp);
1060 return npages_dirty;
1061 }
1062
1063 i = head = *rmapp & KVMPPC_RMAP_INDEX;
1064 do {
1065 unsigned long hptep1;
1066 hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
1067 j = rev[i].forw;
1068
1069 /*
1070 * Checking the C (changed) bit here is racy since there
1071 * is no guarantee about when the hardware writes it back.
1072 * If the HPTE is not writable then it is stable since the
1073 * page can't be written to, and we would have done a tlbie
1074 * (which forces the hardware to complete any writeback)
1075 * when making the HPTE read-only.
1076 * If vcpus are running then this call is racy anyway
1077 * since the page could get dirtied subsequently, so we
1078 * expect there to be a further call which would pick up
1079 * any delayed C bit writeback.
1080 * Otherwise we need to do the tlbie even if C==0 in
1081 * order to pick up any delayed writeback of C.
1082 */
1083 hptep1 = be64_to_cpu(hptep[1]);
1084 if (!(hptep1 & HPTE_R_C) &&
1085 (!hpte_is_writable(hptep1) || vcpus_running(kvm)))
1086 continue;
1087
1088 if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
1089 /* unlock rmap before spinning on the HPTE lock */
1090 unlock_rmap(rmapp);
1091 while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
1092 cpu_relax();
1093 goto retry;
1094 }
1095
1096 /* Now check and modify the HPTE */
1097 if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
1098 __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
1099 continue;
1100 }
1101
1102 /* need to make it temporarily absent so C is stable */
1103 hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
1104 kvmppc_invalidate_hpte(kvm, hptep, i);
1105 v = be64_to_cpu(hptep[0]);
1106 r = be64_to_cpu(hptep[1]);
1107 if (r & HPTE_R_C) {
1108 hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
1109 if (!(rev[i].guest_rpte & HPTE_R_C)) {
1110 rev[i].guest_rpte |= HPTE_R_C;
1111 note_hpte_modification(kvm, &rev[i]);
1112 }
1113 n = hpte_page_size(v, r);
1114 n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
1115 if (n > npages_dirty)
1116 npages_dirty = n;
1117 eieio();
1118 }
1119 v &= ~HPTE_V_ABSENT;
1120 v |= HPTE_V_VALID;
1121 __unlock_hpte(hptep, v);
1122 } while ((i = j) != head);
1123
1124 unlock_rmap(rmapp);
1125 return npages_dirty;
1126 }
1127
kvmppc_harvest_vpa_dirty(struct kvmppc_vpa * vpa,struct kvm_memory_slot * memslot,unsigned long * map)1128 void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
1129 struct kvm_memory_slot *memslot,
1130 unsigned long *map)
1131 {
1132 unsigned long gfn;
1133
1134 if (!vpa->dirty || !vpa->pinned_addr)
1135 return;
1136 gfn = vpa->gpa >> PAGE_SHIFT;
1137 if (gfn < memslot->base_gfn ||
1138 gfn >= memslot->base_gfn + memslot->npages)
1139 return;
1140
1141 vpa->dirty = false;
1142 if (map)
1143 __set_bit_le(gfn - memslot->base_gfn, map);
1144 }
1145
kvmppc_hv_get_dirty_log_hpt(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long * map)1146 long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
1147 struct kvm_memory_slot *memslot, unsigned long *map)
1148 {
1149 unsigned long i, j;
1150 unsigned long *rmapp;
1151
1152 preempt_disable();
1153 rmapp = memslot->arch.rmap;
1154 for (i = 0; i < memslot->npages; ++i) {
1155 int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
1156 /*
1157 * Note that if npages > 0 then i must be a multiple of npages,
1158 * since we always put huge-page HPTEs in the rmap chain
1159 * corresponding to their page base address.
1160 */
1161 if (npages && map)
1162 for (j = i; npages; ++j, --npages)
1163 __set_bit_le(j, map);
1164 ++rmapp;
1165 }
1166 preempt_enable();
1167 return 0;
1168 }
1169
kvmppc_pin_guest_page(struct kvm * kvm,unsigned long gpa,unsigned long * nb_ret)1170 void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
1171 unsigned long *nb_ret)
1172 {
1173 struct kvm_memory_slot *memslot;
1174 unsigned long gfn = gpa >> PAGE_SHIFT;
1175 struct page *page, *pages[1];
1176 int npages;
1177 unsigned long hva, offset;
1178 int srcu_idx;
1179
1180 srcu_idx = srcu_read_lock(&kvm->srcu);
1181 memslot = gfn_to_memslot(kvm, gfn);
1182 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
1183 goto err;
1184 hva = gfn_to_hva_memslot(memslot, gfn);
1185 npages = get_user_pages_fast(hva, 1, 1, pages);
1186 if (npages < 1)
1187 goto err;
1188 page = pages[0];
1189 srcu_read_unlock(&kvm->srcu, srcu_idx);
1190
1191 offset = gpa & (PAGE_SIZE - 1);
1192 if (nb_ret)
1193 *nb_ret = PAGE_SIZE - offset;
1194 return page_address(page) + offset;
1195
1196 err:
1197 srcu_read_unlock(&kvm->srcu, srcu_idx);
1198 return NULL;
1199 }
1200
kvmppc_unpin_guest_page(struct kvm * kvm,void * va,unsigned long gpa,bool dirty)1201 void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
1202 bool dirty)
1203 {
1204 struct page *page = virt_to_page(va);
1205 struct kvm_memory_slot *memslot;
1206 unsigned long gfn;
1207 unsigned long *rmap;
1208 int srcu_idx;
1209
1210 put_page(page);
1211
1212 if (!dirty)
1213 return;
1214
1215 /* We need to mark this page dirty in the rmap chain */
1216 gfn = gpa >> PAGE_SHIFT;
1217 srcu_idx = srcu_read_lock(&kvm->srcu);
1218 memslot = gfn_to_memslot(kvm, gfn);
1219 if (memslot) {
1220 if (!kvm_is_radix(kvm)) {
1221 rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
1222 lock_rmap(rmap);
1223 *rmap |= KVMPPC_RMAP_CHANGED;
1224 unlock_rmap(rmap);
1225 } else if (memslot->dirty_bitmap) {
1226 mark_page_dirty(kvm, gfn);
1227 }
1228 }
1229 srcu_read_unlock(&kvm->srcu, srcu_idx);
1230 }
1231
1232 /*
1233 * HPT resizing
1234 */
resize_hpt_allocate(struct kvm_resize_hpt * resize)1235 static int resize_hpt_allocate(struct kvm_resize_hpt *resize)
1236 {
1237 int rc;
1238
1239 rc = kvmppc_allocate_hpt(&resize->hpt, resize->order);
1240 if (rc < 0)
1241 return rc;
1242
1243 resize_hpt_debug(resize, "resize_hpt_allocate(): HPT @ 0x%lx\n",
1244 resize->hpt.virt);
1245
1246 return 0;
1247 }
1248
resize_hpt_rehash_hpte(struct kvm_resize_hpt * resize,unsigned long idx)1249 static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize,
1250 unsigned long idx)
1251 {
1252 struct kvm *kvm = resize->kvm;
1253 struct kvm_hpt_info *old = &kvm->arch.hpt;
1254 struct kvm_hpt_info *new = &resize->hpt;
1255 unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1;
1256 unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1;
1257 __be64 *hptep, *new_hptep;
1258 unsigned long vpte, rpte, guest_rpte;
1259 int ret;
1260 struct revmap_entry *rev;
1261 unsigned long apsize, psize, avpn, pteg, hash;
1262 unsigned long new_idx, new_pteg, replace_vpte;
1263
1264 hptep = (__be64 *)(old->virt + (idx << 4));
1265
1266 /* Guest is stopped, so new HPTEs can't be added or faulted
1267 * in, only unmapped or altered by host actions. So, it's
1268 * safe to check this before we take the HPTE lock */
1269 vpte = be64_to_cpu(hptep[0]);
1270 if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1271 return 0; /* nothing to do */
1272
1273 while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
1274 cpu_relax();
1275
1276 vpte = be64_to_cpu(hptep[0]);
1277
1278 ret = 0;
1279 if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT))
1280 /* Nothing to do */
1281 goto out;
1282
1283 /* Unmap */
1284 rev = &old->rev[idx];
1285 guest_rpte = rev->guest_rpte;
1286
1287 ret = -EIO;
1288 apsize = hpte_page_size(vpte, guest_rpte);
1289 if (!apsize)
1290 goto out;
1291
1292 if (vpte & HPTE_V_VALID) {
1293 unsigned long gfn = hpte_rpn(guest_rpte, apsize);
1294 int srcu_idx = srcu_read_lock(&kvm->srcu);
1295 struct kvm_memory_slot *memslot =
1296 __gfn_to_memslot(kvm_memslots(kvm), gfn);
1297
1298 if (memslot) {
1299 unsigned long *rmapp;
1300 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1301
1302 lock_rmap(rmapp);
1303 kvmppc_unmap_hpte(kvm, idx, rmapp, gfn);
1304 unlock_rmap(rmapp);
1305 }
1306
1307 srcu_read_unlock(&kvm->srcu, srcu_idx);
1308 }
1309
1310 /* Reload PTE after unmap */
1311 vpte = be64_to_cpu(hptep[0]);
1312
1313 BUG_ON(vpte & HPTE_V_VALID);
1314 BUG_ON(!(vpte & HPTE_V_ABSENT));
1315
1316 ret = 0;
1317 if (!(vpte & HPTE_V_BOLTED))
1318 goto out;
1319
1320 rpte = be64_to_cpu(hptep[1]);
1321 psize = hpte_base_page_size(vpte, rpte);
1322 avpn = HPTE_V_AVPN_VAL(vpte) & ~((psize - 1) >> 23);
1323 pteg = idx / HPTES_PER_GROUP;
1324 if (vpte & HPTE_V_SECONDARY)
1325 pteg = ~pteg;
1326
1327 if (!(vpte & HPTE_V_1TB_SEG)) {
1328 unsigned long offset, vsid;
1329
1330 /* We only have 28 - 23 bits of offset in avpn */
1331 offset = (avpn & 0x1f) << 23;
1332 vsid = avpn >> 5;
1333 /* We can find more bits from the pteg value */
1334 if (psize < (1ULL << 23))
1335 offset |= ((vsid ^ pteg) & old_hash_mask) * psize;
1336
1337 hash = vsid ^ (offset / psize);
1338 } else {
1339 unsigned long offset, vsid;
1340
1341 /* We only have 40 - 23 bits of seg_off in avpn */
1342 offset = (avpn & 0x1ffff) << 23;
1343 vsid = avpn >> 17;
1344 if (psize < (1ULL << 23))
1345 offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) * psize;
1346
1347 hash = vsid ^ (vsid << 25) ^ (offset / psize);
1348 }
1349
1350 new_pteg = hash & new_hash_mask;
1351 if (vpte & HPTE_V_SECONDARY)
1352 new_pteg = ~hash & new_hash_mask;
1353
1354 new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP);
1355 new_hptep = (__be64 *)(new->virt + (new_idx << 4));
1356
1357 replace_vpte = be64_to_cpu(new_hptep[0]);
1358
1359 if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1360 BUG_ON(new->order >= old->order);
1361
1362 if (replace_vpte & HPTE_V_BOLTED) {
1363 if (vpte & HPTE_V_BOLTED)
1364 /* Bolted collision, nothing we can do */
1365 ret = -ENOSPC;
1366 /* Discard the new HPTE */
1367 goto out;
1368 }
1369
1370 /* Discard the previous HPTE */
1371 }
1372
1373 new_hptep[1] = cpu_to_be64(rpte);
1374 new->rev[new_idx].guest_rpte = guest_rpte;
1375 /* No need for a barrier, since new HPT isn't active */
1376 new_hptep[0] = cpu_to_be64(vpte);
1377 unlock_hpte(new_hptep, vpte);
1378
1379 out:
1380 unlock_hpte(hptep, vpte);
1381 return ret;
1382 }
1383
resize_hpt_rehash(struct kvm_resize_hpt * resize)1384 static int resize_hpt_rehash(struct kvm_resize_hpt *resize)
1385 {
1386 struct kvm *kvm = resize->kvm;
1387 unsigned long i;
1388 int rc;
1389
1390 /*
1391 * resize_hpt_rehash_hpte() doesn't handle the new-format HPTEs
1392 * that POWER9 uses, and could well hit a BUG_ON on POWER9.
1393 */
1394 if (cpu_has_feature(CPU_FTR_ARCH_300))
1395 return -EIO;
1396 for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) {
1397 rc = resize_hpt_rehash_hpte(resize, i);
1398 if (rc != 0)
1399 return rc;
1400 }
1401
1402 return 0;
1403 }
1404
resize_hpt_pivot(struct kvm_resize_hpt * resize)1405 static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
1406 {
1407 struct kvm *kvm = resize->kvm;
1408 struct kvm_hpt_info hpt_tmp;
1409
1410 /* Exchange the pending tables in the resize structure with
1411 * the active tables */
1412
1413 resize_hpt_debug(resize, "resize_hpt_pivot()\n");
1414
1415 spin_lock(&kvm->mmu_lock);
1416 asm volatile("ptesync" : : : "memory");
1417
1418 hpt_tmp = kvm->arch.hpt;
1419 kvmppc_set_hpt(kvm, &resize->hpt);
1420 resize->hpt = hpt_tmp;
1421
1422 spin_unlock(&kvm->mmu_lock);
1423
1424 synchronize_srcu_expedited(&kvm->srcu);
1425
1426 resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
1427 }
1428
resize_hpt_release(struct kvm * kvm,struct kvm_resize_hpt * resize)1429 static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
1430 {
1431 if (WARN_ON(!mutex_is_locked(&kvm->lock)))
1432 return;
1433
1434 if (!resize)
1435 return;
1436
1437 if (resize->error != -EBUSY) {
1438 if (resize->hpt.virt)
1439 kvmppc_free_hpt(&resize->hpt);
1440 kfree(resize);
1441 }
1442
1443 if (kvm->arch.resize_hpt == resize)
1444 kvm->arch.resize_hpt = NULL;
1445 }
1446
resize_hpt_prepare_work(struct work_struct * work)1447 static void resize_hpt_prepare_work(struct work_struct *work)
1448 {
1449 struct kvm_resize_hpt *resize = container_of(work,
1450 struct kvm_resize_hpt,
1451 work);
1452 struct kvm *kvm = resize->kvm;
1453 int err = 0;
1454
1455 if (WARN_ON(resize->error != -EBUSY))
1456 return;
1457
1458 mutex_lock(&kvm->lock);
1459
1460 /* Request is still current? */
1461 if (kvm->arch.resize_hpt == resize) {
1462 /* We may request large allocations here:
1463 * do not sleep with kvm->lock held for a while.
1464 */
1465 mutex_unlock(&kvm->lock);
1466
1467 resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
1468 resize->order);
1469
1470 err = resize_hpt_allocate(resize);
1471
1472 /* We have strict assumption about -EBUSY
1473 * when preparing for HPT resize.
1474 */
1475 if (WARN_ON(err == -EBUSY))
1476 err = -EINPROGRESS;
1477
1478 mutex_lock(&kvm->lock);
1479 /* It is possible that kvm->arch.resize_hpt != resize
1480 * after we grab kvm->lock again.
1481 */
1482 }
1483
1484 resize->error = err;
1485
1486 if (kvm->arch.resize_hpt != resize)
1487 resize_hpt_release(kvm, resize);
1488
1489 mutex_unlock(&kvm->lock);
1490 }
1491
kvm_vm_ioctl_resize_hpt_prepare(struct kvm * kvm,struct kvm_ppc_resize_hpt * rhpt)1492 long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
1493 struct kvm_ppc_resize_hpt *rhpt)
1494 {
1495 unsigned long flags = rhpt->flags;
1496 unsigned long shift = rhpt->shift;
1497 struct kvm_resize_hpt *resize;
1498 int ret;
1499
1500 if (flags != 0)
1501 return -EINVAL;
1502
1503 if (shift && ((shift < 18) || (shift > 46)))
1504 return -EINVAL;
1505
1506 mutex_lock(&kvm->lock);
1507
1508 resize = kvm->arch.resize_hpt;
1509
1510 if (resize) {
1511 if (resize->order == shift) {
1512 /* Suitable resize in progress? */
1513 ret = resize->error;
1514 if (ret == -EBUSY)
1515 ret = 100; /* estimated time in ms */
1516 else if (ret)
1517 resize_hpt_release(kvm, resize);
1518
1519 goto out;
1520 }
1521
1522 /* not suitable, cancel it */
1523 resize_hpt_release(kvm, resize);
1524 }
1525
1526 ret = 0;
1527 if (!shift)
1528 goto out; /* nothing to do */
1529
1530 /* start new resize */
1531
1532 resize = kzalloc(sizeof(*resize), GFP_KERNEL);
1533 if (!resize) {
1534 ret = -ENOMEM;
1535 goto out;
1536 }
1537
1538 resize->error = -EBUSY;
1539 resize->order = shift;
1540 resize->kvm = kvm;
1541 INIT_WORK(&resize->work, resize_hpt_prepare_work);
1542 kvm->arch.resize_hpt = resize;
1543
1544 schedule_work(&resize->work);
1545
1546 ret = 100; /* estimated time in ms */
1547
1548 out:
1549 mutex_unlock(&kvm->lock);
1550 return ret;
1551 }
1552
resize_hpt_boot_vcpu(void * opaque)1553 static void resize_hpt_boot_vcpu(void *opaque)
1554 {
1555 /* Nothing to do, just force a KVM exit */
1556 }
1557
kvm_vm_ioctl_resize_hpt_commit(struct kvm * kvm,struct kvm_ppc_resize_hpt * rhpt)1558 long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
1559 struct kvm_ppc_resize_hpt *rhpt)
1560 {
1561 unsigned long flags = rhpt->flags;
1562 unsigned long shift = rhpt->shift;
1563 struct kvm_resize_hpt *resize;
1564 long ret;
1565
1566 if (flags != 0)
1567 return -EINVAL;
1568
1569 if (shift && ((shift < 18) || (shift > 46)))
1570 return -EINVAL;
1571
1572 mutex_lock(&kvm->lock);
1573
1574 resize = kvm->arch.resize_hpt;
1575
1576 /* This shouldn't be possible */
1577 ret = -EIO;
1578 if (WARN_ON(!kvm->arch.hpte_setup_done))
1579 goto out_no_hpt;
1580
1581 /* Stop VCPUs from running while we mess with the HPT */
1582 kvm->arch.hpte_setup_done = 0;
1583 smp_mb();
1584
1585 /* Boot all CPUs out of the guest so they re-read
1586 * hpte_setup_done */
1587 on_each_cpu(resize_hpt_boot_vcpu, NULL, 1);
1588
1589 ret = -ENXIO;
1590 if (!resize || (resize->order != shift))
1591 goto out;
1592
1593 ret = resize->error;
1594 if (ret)
1595 goto out;
1596
1597 ret = resize_hpt_rehash(resize);
1598 if (ret)
1599 goto out;
1600
1601 resize_hpt_pivot(resize);
1602
1603 out:
1604 /* Let VCPUs run again */
1605 kvm->arch.hpte_setup_done = 1;
1606 smp_mb();
1607 out_no_hpt:
1608 resize_hpt_release(kvm, resize);
1609 mutex_unlock(&kvm->lock);
1610 return ret;
1611 }
1612
1613 /*
1614 * Functions for reading and writing the hash table via reads and
1615 * writes on a file descriptor.
1616 *
1617 * Reads return the guest view of the hash table, which has to be
1618 * pieced together from the real hash table and the guest_rpte
1619 * values in the revmap array.
1620 *
1621 * On writes, each HPTE written is considered in turn, and if it
1622 * is valid, it is written to the HPT as if an H_ENTER with the
1623 * exact flag set was done. When the invalid count is non-zero
1624 * in the header written to the stream, the kernel will make
1625 * sure that that many HPTEs are invalid, and invalidate them
1626 * if not.
1627 */
1628
1629 struct kvm_htab_ctx {
1630 unsigned long index;
1631 unsigned long flags;
1632 struct kvm *kvm;
1633 int first_pass;
1634 };
1635
1636 #define HPTE_SIZE (2 * sizeof(unsigned long))
1637
1638 /*
1639 * Returns 1 if this HPT entry has been modified or has pending
1640 * R/C bit changes.
1641 */
hpte_dirty(struct revmap_entry * revp,__be64 * hptp)1642 static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
1643 {
1644 unsigned long rcbits_unset;
1645
1646 if (revp->guest_rpte & HPTE_GR_MODIFIED)
1647 return 1;
1648
1649 /* Also need to consider changes in reference and changed bits */
1650 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1651 if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
1652 (be64_to_cpu(hptp[1]) & rcbits_unset))
1653 return 1;
1654
1655 return 0;
1656 }
1657
record_hpte(unsigned long flags,__be64 * hptp,unsigned long * hpte,struct revmap_entry * revp,int want_valid,int first_pass)1658 static long record_hpte(unsigned long flags, __be64 *hptp,
1659 unsigned long *hpte, struct revmap_entry *revp,
1660 int want_valid, int first_pass)
1661 {
1662 unsigned long v, r, hr;
1663 unsigned long rcbits_unset;
1664 int ok = 1;
1665 int valid, dirty;
1666
1667 /* Unmodified entries are uninteresting except on the first pass */
1668 dirty = hpte_dirty(revp, hptp);
1669 if (!first_pass && !dirty)
1670 return 0;
1671
1672 valid = 0;
1673 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
1674 valid = 1;
1675 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
1676 !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
1677 valid = 0;
1678 }
1679 if (valid != want_valid)
1680 return 0;
1681
1682 v = r = 0;
1683 if (valid || dirty) {
1684 /* lock the HPTE so it's stable and read it */
1685 preempt_disable();
1686 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
1687 cpu_relax();
1688 v = be64_to_cpu(hptp[0]);
1689 hr = be64_to_cpu(hptp[1]);
1690 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1691 v = hpte_new_to_old_v(v, hr);
1692 hr = hpte_new_to_old_r(hr);
1693 }
1694
1695 /* re-evaluate valid and dirty from synchronized HPTE value */
1696 valid = !!(v & HPTE_V_VALID);
1697 dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
1698
1699 /* Harvest R and C into guest view if necessary */
1700 rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
1701 if (valid && (rcbits_unset & hr)) {
1702 revp->guest_rpte |= (hr &
1703 (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
1704 dirty = 1;
1705 }
1706
1707 if (v & HPTE_V_ABSENT) {
1708 v &= ~HPTE_V_ABSENT;
1709 v |= HPTE_V_VALID;
1710 valid = 1;
1711 }
1712 if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
1713 valid = 0;
1714
1715 r = revp->guest_rpte;
1716 /* only clear modified if this is the right sort of entry */
1717 if (valid == want_valid && dirty) {
1718 r &= ~HPTE_GR_MODIFIED;
1719 revp->guest_rpte = r;
1720 }
1721 unlock_hpte(hptp, be64_to_cpu(hptp[0]));
1722 preempt_enable();
1723 if (!(valid == want_valid && (first_pass || dirty)))
1724 ok = 0;
1725 }
1726 hpte[0] = cpu_to_be64(v);
1727 hpte[1] = cpu_to_be64(r);
1728 return ok;
1729 }
1730
kvm_htab_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1731 static ssize_t kvm_htab_read(struct file *file, char __user *buf,
1732 size_t count, loff_t *ppos)
1733 {
1734 struct kvm_htab_ctx *ctx = file->private_data;
1735 struct kvm *kvm = ctx->kvm;
1736 struct kvm_get_htab_header hdr;
1737 __be64 *hptp;
1738 struct revmap_entry *revp;
1739 unsigned long i, nb, nw;
1740 unsigned long __user *lbuf;
1741 struct kvm_get_htab_header __user *hptr;
1742 unsigned long flags;
1743 int first_pass;
1744 unsigned long hpte[2];
1745
1746 if (!access_ok(VERIFY_WRITE, buf, count))
1747 return -EFAULT;
1748
1749 first_pass = ctx->first_pass;
1750 flags = ctx->flags;
1751
1752 i = ctx->index;
1753 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1754 revp = kvm->arch.hpt.rev + i;
1755 lbuf = (unsigned long __user *)buf;
1756
1757 nb = 0;
1758 while (nb + sizeof(hdr) + HPTE_SIZE < count) {
1759 /* Initialize header */
1760 hptr = (struct kvm_get_htab_header __user *)buf;
1761 hdr.n_valid = 0;
1762 hdr.n_invalid = 0;
1763 nw = nb;
1764 nb += sizeof(hdr);
1765 lbuf = (unsigned long __user *)(buf + sizeof(hdr));
1766
1767 /* Skip uninteresting entries, i.e. clean on not-first pass */
1768 if (!first_pass) {
1769 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1770 !hpte_dirty(revp, hptp)) {
1771 ++i;
1772 hptp += 2;
1773 ++revp;
1774 }
1775 }
1776 hdr.index = i;
1777
1778 /* Grab a series of valid entries */
1779 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1780 hdr.n_valid < 0xffff &&
1781 nb + HPTE_SIZE < count &&
1782 record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
1783 /* valid entry, write it out */
1784 ++hdr.n_valid;
1785 if (__put_user(hpte[0], lbuf) ||
1786 __put_user(hpte[1], lbuf + 1))
1787 return -EFAULT;
1788 nb += HPTE_SIZE;
1789 lbuf += 2;
1790 ++i;
1791 hptp += 2;
1792 ++revp;
1793 }
1794 /* Now skip invalid entries while we can */
1795 while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
1796 hdr.n_invalid < 0xffff &&
1797 record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
1798 /* found an invalid entry */
1799 ++hdr.n_invalid;
1800 ++i;
1801 hptp += 2;
1802 ++revp;
1803 }
1804
1805 if (hdr.n_valid || hdr.n_invalid) {
1806 /* write back the header */
1807 if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
1808 return -EFAULT;
1809 nw = nb;
1810 buf = (char __user *)lbuf;
1811 } else {
1812 nb = nw;
1813 }
1814
1815 /* Check if we've wrapped around the hash table */
1816 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) {
1817 i = 0;
1818 ctx->first_pass = 0;
1819 break;
1820 }
1821 }
1822
1823 ctx->index = i;
1824
1825 return nb;
1826 }
1827
kvm_htab_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1828 static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
1829 size_t count, loff_t *ppos)
1830 {
1831 struct kvm_htab_ctx *ctx = file->private_data;
1832 struct kvm *kvm = ctx->kvm;
1833 struct kvm_get_htab_header hdr;
1834 unsigned long i, j;
1835 unsigned long v, r;
1836 unsigned long __user *lbuf;
1837 __be64 *hptp;
1838 unsigned long tmp[2];
1839 ssize_t nb;
1840 long int err, ret;
1841 int hpte_setup;
1842
1843 if (!access_ok(VERIFY_READ, buf, count))
1844 return -EFAULT;
1845
1846 /* lock out vcpus from running while we're doing this */
1847 mutex_lock(&kvm->lock);
1848 hpte_setup = kvm->arch.hpte_setup_done;
1849 if (hpte_setup) {
1850 kvm->arch.hpte_setup_done = 0; /* temporarily */
1851 /* order hpte_setup_done vs. vcpus_running */
1852 smp_mb();
1853 if (atomic_read(&kvm->arch.vcpus_running)) {
1854 kvm->arch.hpte_setup_done = 1;
1855 mutex_unlock(&kvm->lock);
1856 return -EBUSY;
1857 }
1858 }
1859
1860 err = 0;
1861 for (nb = 0; nb + sizeof(hdr) <= count; ) {
1862 err = -EFAULT;
1863 if (__copy_from_user(&hdr, buf, sizeof(hdr)))
1864 break;
1865
1866 err = 0;
1867 if (nb + hdr.n_valid * HPTE_SIZE > count)
1868 break;
1869
1870 nb += sizeof(hdr);
1871 buf += sizeof(hdr);
1872
1873 err = -EINVAL;
1874 i = hdr.index;
1875 if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) ||
1876 i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt))
1877 break;
1878
1879 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
1880 lbuf = (unsigned long __user *)buf;
1881 for (j = 0; j < hdr.n_valid; ++j) {
1882 __be64 hpte_v;
1883 __be64 hpte_r;
1884
1885 err = -EFAULT;
1886 if (__get_user(hpte_v, lbuf) ||
1887 __get_user(hpte_r, lbuf + 1))
1888 goto out;
1889 v = be64_to_cpu(hpte_v);
1890 r = be64_to_cpu(hpte_r);
1891 err = -EINVAL;
1892 if (!(v & HPTE_V_VALID))
1893 goto out;
1894 lbuf += 2;
1895 nb += HPTE_SIZE;
1896
1897 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1898 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1899 err = -EIO;
1900 ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
1901 tmp);
1902 if (ret != H_SUCCESS) {
1903 pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
1904 "r=%lx\n", ret, i, v, r);
1905 goto out;
1906 }
1907 if (!hpte_setup && is_vrma_hpte(v)) {
1908 unsigned long psize = hpte_base_page_size(v, r);
1909 unsigned long senc = slb_pgsize_encoding(psize);
1910 unsigned long lpcr;
1911
1912 kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
1913 (VRMA_VSID << SLB_VSID_SHIFT_1T);
1914 lpcr = senc << (LPCR_VRMASD_SH - 4);
1915 kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
1916 hpte_setup = 1;
1917 }
1918 ++i;
1919 hptp += 2;
1920 }
1921
1922 for (j = 0; j < hdr.n_invalid; ++j) {
1923 if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
1924 kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
1925 ++i;
1926 hptp += 2;
1927 }
1928 err = 0;
1929 }
1930
1931 out:
1932 /* Order HPTE updates vs. hpte_setup_done */
1933 smp_wmb();
1934 kvm->arch.hpte_setup_done = hpte_setup;
1935 mutex_unlock(&kvm->lock);
1936
1937 if (err)
1938 return err;
1939 return nb;
1940 }
1941
kvm_htab_release(struct inode * inode,struct file * filp)1942 static int kvm_htab_release(struct inode *inode, struct file *filp)
1943 {
1944 struct kvm_htab_ctx *ctx = filp->private_data;
1945
1946 filp->private_data = NULL;
1947 if (!(ctx->flags & KVM_GET_HTAB_WRITE))
1948 atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
1949 kvm_put_kvm(ctx->kvm);
1950 kfree(ctx);
1951 return 0;
1952 }
1953
1954 static const struct file_operations kvm_htab_fops = {
1955 .read = kvm_htab_read,
1956 .write = kvm_htab_write,
1957 .llseek = default_llseek,
1958 .release = kvm_htab_release,
1959 };
1960
kvm_vm_ioctl_get_htab_fd(struct kvm * kvm,struct kvm_get_htab_fd * ghf)1961 int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
1962 {
1963 int ret;
1964 struct kvm_htab_ctx *ctx;
1965 int rwflag;
1966
1967 /* reject flags we don't recognize */
1968 if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
1969 return -EINVAL;
1970 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1971 if (!ctx)
1972 return -ENOMEM;
1973 kvm_get_kvm(kvm);
1974 ctx->kvm = kvm;
1975 ctx->index = ghf->start_index;
1976 ctx->flags = ghf->flags;
1977 ctx->first_pass = 1;
1978
1979 rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
1980 ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
1981 if (ret < 0) {
1982 kfree(ctx);
1983 kvm_put_kvm(kvm);
1984 return ret;
1985 }
1986
1987 if (rwflag == O_RDONLY) {
1988 mutex_lock(&kvm->slots_lock);
1989 atomic_inc(&kvm->arch.hpte_mod_interest);
1990 /* make sure kvmppc_do_h_enter etc. see the increment */
1991 synchronize_srcu_expedited(&kvm->srcu);
1992 mutex_unlock(&kvm->slots_lock);
1993 }
1994
1995 return ret;
1996 }
1997
1998 struct debugfs_htab_state {
1999 struct kvm *kvm;
2000 struct mutex mutex;
2001 unsigned long hpt_index;
2002 int chars_left;
2003 int buf_index;
2004 char buf[64];
2005 };
2006
debugfs_htab_open(struct inode * inode,struct file * file)2007 static int debugfs_htab_open(struct inode *inode, struct file *file)
2008 {
2009 struct kvm *kvm = inode->i_private;
2010 struct debugfs_htab_state *p;
2011
2012 p = kzalloc(sizeof(*p), GFP_KERNEL);
2013 if (!p)
2014 return -ENOMEM;
2015
2016 kvm_get_kvm(kvm);
2017 p->kvm = kvm;
2018 mutex_init(&p->mutex);
2019 file->private_data = p;
2020
2021 return nonseekable_open(inode, file);
2022 }
2023
debugfs_htab_release(struct inode * inode,struct file * file)2024 static int debugfs_htab_release(struct inode *inode, struct file *file)
2025 {
2026 struct debugfs_htab_state *p = file->private_data;
2027
2028 kvm_put_kvm(p->kvm);
2029 kfree(p);
2030 return 0;
2031 }
2032
debugfs_htab_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)2033 static ssize_t debugfs_htab_read(struct file *file, char __user *buf,
2034 size_t len, loff_t *ppos)
2035 {
2036 struct debugfs_htab_state *p = file->private_data;
2037 ssize_t ret, r;
2038 unsigned long i, n;
2039 unsigned long v, hr, gr;
2040 struct kvm *kvm;
2041 __be64 *hptp;
2042
2043 ret = mutex_lock_interruptible(&p->mutex);
2044 if (ret)
2045 return ret;
2046
2047 if (p->chars_left) {
2048 n = p->chars_left;
2049 if (n > len)
2050 n = len;
2051 r = copy_to_user(buf, p->buf + p->buf_index, n);
2052 n -= r;
2053 p->chars_left -= n;
2054 p->buf_index += n;
2055 buf += n;
2056 len -= n;
2057 ret = n;
2058 if (r) {
2059 if (!n)
2060 ret = -EFAULT;
2061 goto out;
2062 }
2063 }
2064
2065 kvm = p->kvm;
2066 i = p->hpt_index;
2067 hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE));
2068 for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt);
2069 ++i, hptp += 2) {
2070 if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)))
2071 continue;
2072
2073 /* lock the HPTE so it's stable and read it */
2074 preempt_disable();
2075 while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
2076 cpu_relax();
2077 v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK;
2078 hr = be64_to_cpu(hptp[1]);
2079 gr = kvm->arch.hpt.rev[i].guest_rpte;
2080 unlock_hpte(hptp, v);
2081 preempt_enable();
2082
2083 if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT)))
2084 continue;
2085
2086 n = scnprintf(p->buf, sizeof(p->buf),
2087 "%6lx %.16lx %.16lx %.16lx\n",
2088 i, v, hr, gr);
2089 p->chars_left = n;
2090 if (n > len)
2091 n = len;
2092 r = copy_to_user(buf, p->buf, n);
2093 n -= r;
2094 p->chars_left -= n;
2095 p->buf_index = n;
2096 buf += n;
2097 len -= n;
2098 ret += n;
2099 if (r) {
2100 if (!ret)
2101 ret = -EFAULT;
2102 goto out;
2103 }
2104 }
2105 p->hpt_index = i;
2106
2107 out:
2108 mutex_unlock(&p->mutex);
2109 return ret;
2110 }
2111
debugfs_htab_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)2112 static ssize_t debugfs_htab_write(struct file *file, const char __user *buf,
2113 size_t len, loff_t *ppos)
2114 {
2115 return -EACCES;
2116 }
2117
2118 static const struct file_operations debugfs_htab_fops = {
2119 .owner = THIS_MODULE,
2120 .open = debugfs_htab_open,
2121 .release = debugfs_htab_release,
2122 .read = debugfs_htab_read,
2123 .write = debugfs_htab_write,
2124 .llseek = generic_file_llseek,
2125 };
2126
kvmppc_mmu_debugfs_init(struct kvm * kvm)2127 void kvmppc_mmu_debugfs_init(struct kvm *kvm)
2128 {
2129 kvm->arch.htab_dentry = debugfs_create_file("htab", 0400,
2130 kvm->arch.debugfs_dir, kvm,
2131 &debugfs_htab_fops);
2132 }
2133
kvmppc_mmu_book3s_hv_init(struct kvm_vcpu * vcpu)2134 void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
2135 {
2136 struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
2137
2138 vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */
2139
2140 if (kvm_is_radix(vcpu->kvm))
2141 mmu->xlate = kvmppc_mmu_radix_xlate;
2142 else
2143 mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
2144 mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
2145
2146 vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
2147 }
2148