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 (vcpu->arch.shared->msr & 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_gfn_to_pfn(vcpu, gfn, iswrite, &writable);
 108         if (is_error_noslot_pfn(pfn)) {
 109                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", gfn);
 110                 r = -EINVAL;
 111                 goto out;
 112         }
 113         hpaddr = pfn << PAGE_SHIFT;
 114
 115         /* and write the mapping ea -> hpa into the pt */
 116         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 117         map = find_sid_vsid(vcpu, vsid);
 118         if (!map) {
 119                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 120                 WARN_ON(ret < 0);
 121                 map = find_sid_vsid(vcpu, vsid);
 122         }
 123         if (!map) {
 124                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 125                                 vsid, orig_pte->eaddr);
 126                 WARN_ON(true);
 127                 r = -EINVAL;
 128                 goto out;
 129         }
 130
 131         vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
 132
 133         kvm_set_pfn_accessed(pfn);
 134         if (!orig_pte->may_write || !writable)
 135                 rflags |= PP_RXRX;
 136         else {
 137                 mark_page_dirty(vcpu->kvm, gfn);
 138                 kvm_set_pfn_dirty(pfn);
 139         }
 140
 141         if (!orig_pte->may_execute)
 142                 rflags |= HPTE_R_N;
 143         else
 144                 kvmppc_mmu_flush_icache(pfn);
 145
 146         /*
 147          * Use 64K pages if possible; otherwise, on 64K page kernels,
 148          * we need to transfer 4 more bits from guest real to host real addr.
 149          */
 150         if (vsid & VSID_64K)
 151                 hpsize = MMU_PAGE_64K;
 152         else
 153                 hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 154
 155         hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
 156
 157         cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 158
 159         spin_lock(&kvm->mmu_lock);
 160         if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
 161                 r = -EAGAIN;
 162                 goto out_unlock;
 163         }
 164
 165 map_again:
 166         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 167
 168         /* In case we tried normal mapping already, let's nuke old entries */
 169         if (attempt > 1)
 170                 if (ppc_md.hpte_remove(hpteg) < 0) {
 171                         r = -1;
 172                         goto out_unlock;
 173                 }
 174
 175         ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 176                                  hpsize, hpsize, MMU_SEGSIZE_256M);
 177
 178         if (ret < 0) {
 179                 /* If we couldn't map a primary PTE, try a secondary */
 180                 hash = ~hash;
 181                 vflags ^= HPTE_V_SECONDARY;
 182                 attempt++;
 183                 goto map_again;
 184         } else {
 185                 trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 186                                             vpn, hpaddr, orig_pte);
 187
 188                 /* The ppc_md code may give us a secondary entry even though we
 189                    asked for a primary. Fix up. */
 190                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 191                         hash = ~hash;
 192                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 193                 }
 194
 195                 cpte->slot = hpteg + (ret & 7);
 196                 cpte->host_vpn = vpn;
 197                 cpte->pte = *orig_pte;
 198                 cpte->pfn = pfn;
 199                 cpte->pagesize = hpsize;
 200
 201                 kvmppc_mmu_hpte_cache_map(vcpu, cpte);
 202                 cpte = NULL;
 203         }
 204
 205 out_unlock:
 206         spin_unlock(&kvm->mmu_lock);
 207         kvm_release_pfn_clean(pfn);
 208         if (cpte)
 209                 kvmppc_mmu_hpte_cache_free(cpte);
 210
 211 out:
 212         return r;
 213 }
 214
 215 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 216 {
 217         u64 mask = 0xfffffffffULL;
 218         u64 vsid;
 219
 220         vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
 221         if (vsid & VSID_64K)
 222                 mask = 0xffffffff0ULL;
 223         kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
 224 }
 225
 226 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 227 {
 228         struct kvmppc_sid_map *map;
 229         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 230         u16 sid_map_mask;
 231         static int backwards_map = 0;
 232
 233         if (vcpu->arch.shared->msr & MSR_PR)
 234                 gvsid |= VSID_PR;
 235
 236         /* We might get collisions that trap in preceding order, so let's
 237            map them differently */
 238
 239         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 240         if (backwards_map)
 241                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 242
 243         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 244
 245         /* Make sure we're taking the other map next time */
 246         backwards_map = !backwards_map;
 247
 248         /* Uh-oh ... out of mappings. Let's flush! */
 249         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 250                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 251                 memset(vcpu_book3s->sid_map, 0,
 252                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 253                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 254                 kvmppc_mmu_flush_segments(vcpu);
 255         }
 256         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 257
 258         map->guest_vsid = gvsid;
 259         map->valid = true;
 260
 261         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 262
 263         return map;
 264 }
 265
 266 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 267 {
 268         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 269         int i;
 270         int max_slb_size = 64;
 271         int found_inval = -1;
 272         int r;
 273
 274         if (!svcpu->slb_max)
 275                 svcpu->slb_max = 1;
 276
 277         /* Are we overwriting? */
 278         for (i = 1; i < svcpu->slb_max; i++) {
 279                 if (!(svcpu->slb[i].esid & SLB_ESID_V))
 280                         found_inval = i;
 281                 else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 282                         r = i;
 283                         goto out;
 284                 }
 285         }
 286
 287         /* Found a spare entry that was invalidated before */
 288         if (found_inval > 0) {
 289                 r = found_inval;
 290                 goto out;
 291         }
 292
 293         /* No spare invalid entry, so create one */
 294
 295         if (mmu_slb_size < 64)
 296                 max_slb_size = mmu_slb_size;
 297
 298         /* Overflowing -> purge */
 299         if ((svcpu->slb_max) == max_slb_size)
 300                 kvmppc_mmu_flush_segments(vcpu);
 301
 302         r = svcpu->slb_max;
 303         svcpu->slb_max++;
 304
 305 out:
 306         svcpu_put(svcpu);
 307         return r;
 308 }
 309
 310 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 311 {
 312         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 313         u64 esid = eaddr >> SID_SHIFT;
 314         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 315         u64 slb_vsid = SLB_VSID_USER;
 316         u64 gvsid;
 317         int slb_index;
 318         struct kvmppc_sid_map *map;
 319         int r = 0;
 320
 321         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 322
 323         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 324                 /* Invalidate an entry */
 325                 svcpu->slb[slb_index].esid = 0;
 326                 r = -ENOENT;
 327                 goto out;
 328         }
 329
 330         map = find_sid_vsid(vcpu, gvsid);
 331         if (!map)
 332                 map = create_sid_map(vcpu, gvsid);
 333
 334         map->guest_esid = esid;
 335
 336         slb_vsid |= (map->host_vsid << 12);
 337         slb_vsid &= ~SLB_VSID_KP;
 338         slb_esid |= slb_index;
 339
 340 #ifdef CONFIG_PPC_64K_PAGES
 341         /* Set host segment base page size to 64K if possible */
 342         if (gvsid & VSID_64K)
 343                 slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
 344 #endif
 345
 346         svcpu->slb[slb_index].esid = slb_esid;
 347         svcpu->slb[slb_index].vsid = slb_vsid;
 348
 349         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 350
 351 out:
 352         svcpu_put(svcpu);
 353         return r;
 354 }
 355
 356 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
 357 {
 358         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 359         ulong seg_mask = -seg_size;
 360         int i;
 361
 362         for (i = 1; i < svcpu->slb_max; i++) {
 363                 if ((svcpu->slb[i].esid & SLB_ESID_V) &&
 364                     (svcpu->slb[i].esid & seg_mask) == ea) {
 365                         /* Invalidate this entry */
 366                         svcpu->slb[i].esid = 0;
 367                 }
 368         }
 369
 370         svcpu_put(svcpu);
 371 }
 372
 373 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 374 {
 375         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 376         svcpu->slb_max = 1;
 377         svcpu->slb[0].esid = 0;
 378         svcpu_put(svcpu);
 379 }
 380
 381 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
 382 {
 383         kvmppc_mmu_hpte_destroy(vcpu);
 384         __destroy_context(to_book3s(vcpu)->context_id[0]);
 385 }
 386
 387 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 388 {
 389         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 390         int err;
 391
 392         err = __init_new_context();
 393         if (err < 0)
 394                 return -1;
 395         vcpu3s->context_id[0] = err;
 396
 397         vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 398                                   << ESID_BITS) - 1;
 399         vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 400         vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 401
 402         kvmppc_mmu_hpte_init(vcpu);
 403
 404         return 0;
 405 }