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/book3s/64/mmu-hash.h>
  27 #include <asm/machdep.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/hw_irq.h>
  30 #include "trace_pr.h"
  31 #include "book3s.h"
  32
  33 #define PTE_SIZE 12
  34
  35 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  36 {
  37         ppc_md.hpte_invalidate(pte->slot, pte->host_vpn,
  38                                pte->pagesize, pte->pagesize, MMU_SEGSIZE_256M,
  39                                false);
  40 }
  41
  42 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  43  * a hash, so we don't waste cycles on looping */
  44 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
  45 {
  46         return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
  47                      ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
  48                      ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
  49                      ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
  50                      ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
  51                      ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
  52                      ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
  53                      ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
  54 }
  55
  56
  57 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
  58 {
  59         struct kvmppc_sid_map *map;
  60         u16 sid_map_mask;
  61
  62         if (kvmppc_get_msr(vcpu) & MSR_PR)
  63                 gvsid |= VSID_PR;
  64
  65         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
  66         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
  67         if (map->valid && (map->guest_vsid == gvsid)) {
  68                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  69                 return map;
  70         }
  71
  72         map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
  73         if (map->valid && (map->guest_vsid == gvsid)) {
  74                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  75                 return map;
  76         }
  77
  78         trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
  79         return NULL;
  80 }
  81
  82 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
  83                         bool iswrite)
  84 {
  85         unsigned long vpn;
  86         kvm_pfn_t hpaddr;
  87         ulong hash, hpteg;
  88         u64 vsid;
  89         int ret;
  90         int rflags = 0x192;
  91         int vflags = 0;
  92         int attempt = 0;
  93         struct kvmppc_sid_map *map;
  94         int r = 0;
  95         int hpsize = MMU_PAGE_4K;
  96         bool writable;
  97         unsigned long mmu_seq;
  98         struct kvm *kvm = vcpu->kvm;
  99         struct hpte_cache *cpte;
 100         unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
 101         unsigned long pfn;
 102
 103         /* used to check for invalidations in progress */
 104         mmu_seq = kvm->mmu_notifier_seq;
 105         smp_rmb();
 106
 107         /* Get host physical address for gpa */
 108         pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
 109         if (is_error_noslot_pfn(pfn)) {
 110                 printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
 111                        orig_pte->raddr);
 112                 r = -EINVAL;
 113                 goto out;
 114         }
 115         hpaddr = pfn << PAGE_SHIFT;
 116
 117         /* and write the mapping ea -> hpa into the pt */
 118         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 119         map = find_sid_vsid(vcpu, vsid);
 120         if (!map) {
 121                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 122                 WARN_ON(ret < 0);
 123                 map = find_sid_vsid(vcpu, vsid);
 124         }
 125         if (!map) {
 126                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 127                                 vsid, orig_pte->eaddr);
 128                 WARN_ON(true);
 129                 r = -EINVAL;
 130                 goto out;
 131         }
 132
 133         vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
 134
 135         kvm_set_pfn_accessed(pfn);
 136         if (!orig_pte->may_write || !writable)
 137                 rflags |= PP_RXRX;
 138         else {
 139                 mark_page_dirty(vcpu->kvm, gfn);
 140                 kvm_set_pfn_dirty(pfn);
 141         }
 142
 143         if (!orig_pte->may_execute)
 144                 rflags |= HPTE_R_N;
 145         else
 146                 kvmppc_mmu_flush_icache(pfn);
 147
 148         /*
 149          * Use 64K pages if possible; otherwise, on 64K page kernels,
 150          * we need to transfer 4 more bits from guest real to host real addr.
 151          */
 152         if (vsid & VSID_64K)
 153                 hpsize = MMU_PAGE_64K;
 154         else
 155                 hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 156
 157         hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
 158
 159         cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 160
 161         spin_lock(&kvm->mmu_lock);
 162         if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
 163                 r = -EAGAIN;
 164                 goto out_unlock;
 165         }
 166
 167 map_again:
 168         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 169
 170         /* In case we tried normal mapping already, let's nuke old entries */
 171         if (attempt > 1)
 172                 if (ppc_md.hpte_remove(hpteg) < 0) {
 173                         r = -1;
 174                         goto out_unlock;
 175                 }
 176
 177         ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 178                                  hpsize, hpsize, MMU_SEGSIZE_256M);
 179
 180         if (ret < 0) {
 181                 /* If we couldn't map a primary PTE, try a secondary */
 182                 hash = ~hash;
 183                 vflags ^= HPTE_V_SECONDARY;
 184                 attempt++;
 185                 goto map_again;
 186         } else {
 187                 trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 188                                             vpn, hpaddr, orig_pte);
 189
 190                 /* The ppc_md code may give us a secondary entry even though we
 191                    asked for a primary. Fix up. */
 192                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 193                         hash = ~hash;
 194                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 195                 }
 196
 197                 cpte->slot = hpteg + (ret & 7);
 198                 cpte->host_vpn = vpn;
 199                 cpte->pte = *orig_pte;
 200                 cpte->pfn = pfn;
 201                 cpte->pagesize = hpsize;
 202
 203                 kvmppc_mmu_hpte_cache_map(vcpu, cpte);
 204                 cpte = NULL;
 205         }
 206
 207 out_unlock:
 208         spin_unlock(&kvm->mmu_lock);
 209         kvm_release_pfn_clean(pfn);
 210         if (cpte)
 211                 kvmppc_mmu_hpte_cache_free(cpte);
 212
 213 out:
 214         return r;
 215 }
 216
 217 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 218 {
 219         u64 mask = 0xfffffffffULL;
 220         u64 vsid;
 221
 222         vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
 223         if (vsid & VSID_64K)
 224                 mask = 0xffffffff0ULL;
 225         kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
 226 }
 227
 228 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 229 {
 230         struct kvmppc_sid_map *map;
 231         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 232         u16 sid_map_mask;
 233         static int backwards_map = 0;
 234
 235         if (kvmppc_get_msr(vcpu) & MSR_PR)
 236                 gvsid |= VSID_PR;
 237
 238         /* We might get collisions that trap in preceding order, so let's
 239            map them differently */
 240
 241         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 242         if (backwards_map)
 243                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 244
 245         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 246
 247         /* Make sure we're taking the other map next time */
 248         backwards_map = !backwards_map;
 249
 250         /* Uh-oh ... out of mappings. Let's flush! */
 251         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 252                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 253                 memset(vcpu_book3s->sid_map, 0,
 254                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 255                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 256                 kvmppc_mmu_flush_segments(vcpu);
 257         }
 258         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 259
 260         map->guest_vsid = gvsid;
 261         map->valid = true;
 262
 263         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 264
 265         return map;
 266 }
 267
 268 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 269 {
 270         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 271         int i;
 272         int max_slb_size = 64;
 273         int found_inval = -1;
 274         int r;
 275
 276         /* Are we overwriting? */
 277         for (i = 0; i < svcpu->slb_max; i++) {
 278                 if (!(svcpu->slb[i].esid & SLB_ESID_V))
 279                         found_inval = i;
 280                 else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 281                         r = i;
 282                         goto out;
 283                 }
 284         }
 285
 286         /* Found a spare entry that was invalidated before */
 287         if (found_inval >= 0) {
 288                 r = found_inval;
 289                 goto out;
 290         }
 291
 292         /* No spare invalid entry, so create one */
 293
 294         if (mmu_slb_size < 64)
 295                 max_slb_size = mmu_slb_size;
 296
 297         /* Overflowing -> purge */
 298         if ((svcpu->slb_max) == max_slb_size)
 299                 kvmppc_mmu_flush_segments(vcpu);
 300
 301         r = svcpu->slb_max;
 302         svcpu->slb_max++;
 303
 304 out:
 305         svcpu_put(svcpu);
 306         return r;
 307 }
 308
 309 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 310 {
 311         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 312         u64 esid = eaddr >> SID_SHIFT;
 313         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 314         u64 slb_vsid = SLB_VSID_USER;
 315         u64 gvsid;
 316         int slb_index;
 317         struct kvmppc_sid_map *map;
 318         int r = 0;
 319
 320         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 321
 322         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 323                 /* Invalidate an entry */
 324                 svcpu->slb[slb_index].esid = 0;
 325                 r = -ENOENT;
 326                 goto out;
 327         }
 328
 329         map = find_sid_vsid(vcpu, gvsid);
 330         if (!map)
 331                 map = create_sid_map(vcpu, gvsid);
 332
 333         map->guest_esid = esid;
 334
 335         slb_vsid |= (map->host_vsid << 12);
 336         slb_vsid &= ~SLB_VSID_KP;
 337         slb_esid |= slb_index;
 338
 339 #ifdef CONFIG_PPC_64K_PAGES
 340         /* Set host segment base page size to 64K if possible */
 341         if (gvsid & VSID_64K)
 342                 slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
 343 #endif
 344
 345         svcpu->slb[slb_index].esid = slb_esid;
 346         svcpu->slb[slb_index].vsid = slb_vsid;
 347
 348         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 349
 350 out:
 351         svcpu_put(svcpu);
 352         return r;
 353 }
 354
 355 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
 356 {
 357         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 358         ulong seg_mask = -seg_size;
 359         int i;
 360
 361         for (i = 0; i < svcpu->slb_max; i++) {
 362                 if ((svcpu->slb[i].esid & SLB_ESID_V) &&
 363                     (svcpu->slb[i].esid & seg_mask) == ea) {
 364                         /* Invalidate this entry */
 365                         svcpu->slb[i].esid = 0;
 366                 }
 367         }
 368
 369         svcpu_put(svcpu);
 370 }
 371
 372 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 373 {
 374         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 375         svcpu->slb_max = 0;
 376         svcpu->slb[0].esid = 0;
 377         svcpu_put(svcpu);
 378 }
 379
 380 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
 381 {
 382         kvmppc_mmu_hpte_destroy(vcpu);
 383         __destroy_context(to_book3s(vcpu)->context_id[0]);
 384 }
 385
 386 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 387 {
 388         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 389         int err;
 390
 391         err = __init_new_context();
 392         if (err < 0)
 393                 return -1;
 394         vcpu3s->context_id[0] = err;
 395
 396         vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 397                                   << ESID_BITS) - 1;
 398         vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 399         vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 400
 401         kvmppc_mmu_hpte_init(vcpu);
 402
 403         return 0;
 404 }