arch/powerpc/kvm/book3s_64_mmu_host.c

   1 /*
   2  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
   3  *
   4  * Authors:
   5  *     Alexander Graf <agraf@suse.de>
   6  *     Kevin Wolf <mail@kevin-wolf.de>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License, version 2, as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  */
  21
  22 #include <linux/kvm_host.h>
  23
  24 #include <asm/kvm_ppc.h>
  25 #include <asm/kvm_book3s.h>
  26 #include <asm/mmu-hash64.h>
  27 #include <asm/machdep.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/hw_irq.h>
  30 #include "trace_pr.h"
  31
  32 #define PTE_SIZE 12
  33
  34 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  35 {
  36         ppc_md.hpte_invalidate(pte->slot, pte->host_vpn,
  37                                pte->pagesize, pte->pagesize, MMU_SEGSIZE_256M,
  38                                false);
  39 }
  40
  41 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  42  * a hash, so we don't waste cycles on looping */
  43 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
  44 {
  45         return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
  46                      ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
  47                      ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
  48                      ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
  49                      ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
  50                      ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
  51                      ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
  52                      ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
  53 }
  54
  55
  56 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
  57 {
  58         struct kvmppc_sid_map *map;
  59         u16 sid_map_mask;
  60
  61         if (kvmppc_get_msr(vcpu) & MSR_PR)
  62                 gvsid |= VSID_PR;
  63
  64         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
  65         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
  66         if (map->valid && (map->guest_vsid == gvsid)) {
  67                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  68                 return map;
  69         }
  70
  71         map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
  72         if (map->valid && (map->guest_vsid == gvsid)) {
  73                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  74                 return map;
  75         }
  76
  77         trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
  78         return NULL;
  79 }
  80
  81 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
  82                         bool iswrite)
  83 {
  84         unsigned long vpn;
  85         pfn_t hpaddr;
  86         ulong hash, hpteg;
  87         u64 vsid;
  88         int ret;
  89         int rflags = 0x192;
  90         int vflags = 0;
  91         int attempt = 0;
  92         struct kvmppc_sid_map *map;
  93         int r = 0;
  94         int hpsize = MMU_PAGE_4K;
  95         bool writable;
  96         unsigned long mmu_seq;
  97         struct kvm *kvm = vcpu->kvm;
  98         struct hpte_cache *cpte;
  99         unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
 100         unsigned long pfn;
 101
 102         /* used to check for invalidations in progress */
 103         mmu_seq = kvm->mmu_notifier_seq;
 104         smp_rmb();
 105
 106         /* Get host physical address for gpa */
 107         pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
 108         if (is_error_noslot_pfn(pfn)) {
 109                 printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
 110                        orig_pte->raddr);
 111                 r = -EINVAL;
 112                 goto out;
 113         }
 114         hpaddr = pfn << PAGE_SHIFT;
 115
 116         /* and write the mapping ea -> hpa into the pt */
 117         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 118         map = find_sid_vsid(vcpu, vsid);
 119         if (!map) {
 120                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 121                 WARN_ON(ret < 0);
 122                 map = find_sid_vsid(vcpu, vsid);
 123         }
 124         if (!map) {
 125                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 126                                 vsid, orig_pte->eaddr);
 127                 WARN_ON(true);
 128                 r = -EINVAL;
 129                 goto out;
 130         }
 131
 132         vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
 133
 134         kvm_set_pfn_accessed(pfn);
 135         if (!orig_pte->may_write || !writable)
 136                 rflags |= PP_RXRX;
 137         else {
 138                 mark_page_dirty(vcpu->kvm, gfn);
 139                 kvm_set_pfn_dirty(pfn);
 140         }
 141
 142         if (!orig_pte->may_execute)
 143                 rflags |= HPTE_R_N;
 144         else
 145                 kvmppc_mmu_flush_icache(pfn);
 146
 147         /*
 148          * Use 64K pages if possible; otherwise, on 64K page kernels,
 149          * we need to transfer 4 more bits from guest real to host real addr.
 150          */
 151         if (vsid & VSID_64K)
 152                 hpsize = MMU_PAGE_64K;
 153         else
 154                 hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 155
 156         hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
 157
 158         cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 159
 160         spin_lock(&kvm->mmu_lock);
 161         if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
 162                 r = -EAGAIN;
 163                 goto out_unlock;
 164         }
 165
 166 map_again:
 167         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 168
 169         /* In case we tried normal mapping already, let's nuke old entries */
 170         if (attempt > 1)
 171                 if (ppc_md.hpte_remove(hpteg) < 0) {
 172                         r = -1;
 173                         goto out_unlock;
 174                 }
 175
 176         ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 177                                  hpsize, hpsize, MMU_SEGSIZE_256M);
 178
 179         if (ret < 0) {
 180                 /* If we couldn't map a primary PTE, try a secondary */
 181                 hash = ~hash;
 182                 vflags ^= HPTE_V_SECONDARY;
 183                 attempt++;
 184                 goto map_again;
 185         } else {
 186                 trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 187                                             vpn, hpaddr, orig_pte);
 188
 189                 /* The ppc_md code may give us a secondary entry even though we
 190                    asked for a primary. Fix up. */
 191                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 192                         hash = ~hash;
 193                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 194                 }
 195
 196                 cpte->slot = hpteg + (ret & 7);
 197                 cpte->host_vpn = vpn;
 198                 cpte->pte = *orig_pte;
 199                 cpte->pfn = pfn;
 200                 cpte->pagesize = hpsize;
 201
 202                 kvmppc_mmu_hpte_cache_map(vcpu, cpte);
 203                 cpte = NULL;
 204         }
 205
 206 out_unlock:
 207         spin_unlock(&kvm->mmu_lock);
 208         kvm_release_pfn_clean(pfn);
 209         if (cpte)
 210                 kvmppc_mmu_hpte_cache_free(cpte);
 211
 212 out:
 213         return r;
 214 }
 215
 216 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 217 {
 218         u64 mask = 0xfffffffffULL;
 219         u64 vsid;
 220
 221         vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
 222         if (vsid & VSID_64K)
 223                 mask = 0xffffffff0ULL;
 224         kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
 225 }
 226
 227 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 228 {
 229         struct kvmppc_sid_map *map;
 230         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 231         u16 sid_map_mask;
 232         static int backwards_map = 0;
 233
 234         if (kvmppc_get_msr(vcpu) & MSR_PR)
 235                 gvsid |= VSID_PR;
 236
 237         /* We might get collisions that trap in preceding order, so let's
 238            map them differently */
 239
 240         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 241         if (backwards_map)
 242                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 243
 244         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 245
 246         /* Make sure we're taking the other map next time */
 247         backwards_map = !backwards_map;
 248
 249         /* Uh-oh ... out of mappings. Let's flush! */
 250         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 251                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 252                 memset(vcpu_book3s->sid_map, 0,
 253                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 254                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 255                 kvmppc_mmu_flush_segments(vcpu);
 256         }
 257         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 258
 259         map->guest_vsid = gvsid;
 260         map->valid = true;
 261
 262         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 263
 264         return map;
 265 }
 266
 267 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 268 {
 269         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 270         int i;
 271         int max_slb_size = 64;
 272         int found_inval = -1;
 273         int r;
 274
 275         /* Are we overwriting? */
 276         for (i = 0; i < svcpu->slb_max; i++) {
 277                 if (!(svcpu->slb[i].esid & SLB_ESID_V))
 278                         found_inval = i;
 279                 else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 280                         r = i;
 281                         goto out;
 282                 }
 283         }
 284
 285         /* Found a spare entry that was invalidated before */
 286         if (found_inval >= 0) {
 287                 r = found_inval;
 288                 goto out;
 289         }
 290
 291         /* No spare invalid entry, so create one */
 292
 293         if (mmu_slb_size < 64)
 294                 max_slb_size = mmu_slb_size;
 295
 296         /* Overflowing -> purge */
 297         if ((svcpu->slb_max) == max_slb_size)
 298                 kvmppc_mmu_flush_segments(vcpu);
 299
 300         r = svcpu->slb_max;
 301         svcpu->slb_max++;
 302
 303 out:
 304         svcpu_put(svcpu);
 305         return r;
 306 }
 307
 308 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 309 {
 310         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 311         u64 esid = eaddr >> SID_SHIFT;
 312         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 313         u64 slb_vsid = SLB_VSID_USER;
 314         u64 gvsid;
 315         int slb_index;
 316         struct kvmppc_sid_map *map;
 317         int r = 0;
 318
 319         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 320
 321         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 322                 /* Invalidate an entry */
 323                 svcpu->slb[slb_index].esid = 0;
 324                 r = -ENOENT;
 325                 goto out;
 326         }
 327
 328         map = find_sid_vsid(vcpu, gvsid);
 329         if (!map)
 330                 map = create_sid_map(vcpu, gvsid);
 331
 332         map->guest_esid = esid;
 333
 334         slb_vsid |= (map->host_vsid << 12);
 335         slb_vsid &= ~SLB_VSID_KP;
 336         slb_esid |= slb_index;
 337
 338 #ifdef CONFIG_PPC_64K_PAGES
 339         /* Set host segment base page size to 64K if possible */
 340         if (gvsid & VSID_64K)
 341                 slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
 342 #endif
 343
 344         svcpu->slb[slb_index].esid = slb_esid;
 345         svcpu->slb[slb_index].vsid = slb_vsid;
 346
 347         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 348
 349 out:
 350         svcpu_put(svcpu);
 351         return r;
 352 }
 353
 354 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
 355 {
 356         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 357         ulong seg_mask = -seg_size;
 358         int i;
 359
 360         for (i = 0; i < svcpu->slb_max; i++) {
 361                 if ((svcpu->slb[i].esid & SLB_ESID_V) &&
 362                     (svcpu->slb[i].esid & seg_mask) == ea) {
 363                         /* Invalidate this entry */
 364                         svcpu->slb[i].esid = 0;
 365                 }
 366         }
 367
 368         svcpu_put(svcpu);
 369 }
 370
 371 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 372 {
 373         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 374         svcpu->slb_max = 0;
 375         svcpu->slb[0].esid = 0;
 376         svcpu_put(svcpu);
 377 }
 378
 379 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
 380 {
 381         kvmppc_mmu_hpte_destroy(vcpu);
 382         __destroy_context(to_book3s(vcpu)->context_id[0]);
 383 }
 384
 385 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 386 {
 387         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 388         int err;
 389
 390         err = __init_new_context();
 391         if (err < 0)
 392                 return -1;
 393         vcpu3s->context_id[0] = err;
 394
 395         vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 396                                   << ESID_BITS) - 1;
 397         vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 398         vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 399
 400         kvmppc_mmu_hpte_init(vcpu);
 401
 402         return 0;
 403 }