release/src-rt-6.x.4708/linux/linux-2.6.36/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 #include <linux/hash.h>
  24
  25 #include <asm/kvm_ppc.h>
  26 #include <asm/kvm_book3s.h>
  27 #include <asm/mmu-hash64.h>
  28 #include <asm/machdep.h>
  29 #include <asm/mmu_context.h>
  30 #include <asm/hw_irq.h>
  31
  32 #define PTE_SIZE 12
  33 #define VSID_ALL 0
  34
  35 /* #define DEBUG_MMU */
  36 /* #define DEBUG_SLB */
  37
  38 #ifdef DEBUG_MMU
  39 #define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
  40 #else
  41 #define dprintk_mmu(a, ...) do { } while(0)
  42 #endif
  43
  44 #ifdef DEBUG_SLB
  45 #define dprintk_slb(a, ...) printk(KERN_INFO a, __VA_ARGS__)
  46 #else
  47 #define dprintk_slb(a, ...) do { } while(0)
  48 #endif
  49
  50 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  51 {
  52         ppc_md.hpte_invalidate(pte->slot, pte->host_va,
  53                                MMU_PAGE_4K, MMU_SEGSIZE_256M,
  54                                false);
  55 }
  56
  57 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  58  * a hash, so we don't waste cycles on looping */
  59 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
  60 {
  61         return hash_64(gvsid, SID_MAP_BITS);
  62 }
  63
  64 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
  65 {
  66         struct kvmppc_sid_map *map;
  67         u16 sid_map_mask;
  68
  69         if (vcpu->arch.msr & MSR_PR)
  70                 gvsid |= VSID_PR;
  71
  72         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
  73         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
  74         if (map->guest_vsid == gvsid) {
  75                 dprintk_slb("SLB: Searching: 0x%llx -> 0x%llx\n",
  76                             gvsid, map->host_vsid);
  77                 return map;
  78         }
  79
  80         map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
  81         if (map->guest_vsid == gvsid) {
  82                 dprintk_slb("SLB: Searching 0x%llx -> 0x%llx\n",
  83                             gvsid, map->host_vsid);
  84                 return map;
  85         }
  86
  87         dprintk_slb("SLB: Searching %d/%d: 0x%llx -> not found\n",
  88                     sid_map_mask, SID_MAP_MASK - sid_map_mask, gvsid);
  89         return NULL;
  90 }
  91
  92 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
  93 {
  94         pfn_t hpaddr;
  95         ulong hash, hpteg, va;
  96         u64 vsid;
  97         int ret;
  98         int rflags = 0x192;
  99         int vflags = 0;
 100         int attempt = 0;
 101         struct kvmppc_sid_map *map;
 102
 103         /* Get host physical address for gpa */
 104         hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 105         if (kvm_is_error_hva(hpaddr)) {
 106                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
 107                 return -EINVAL;
 108         }
 109         hpaddr <<= PAGE_SHIFT;
 110 #if PAGE_SHIFT == 12
 111 #elif PAGE_SHIFT == 16
 112         hpaddr |= orig_pte->raddr & 0xf000;
 113 #else
 114 #error Unknown page size
 115 #endif
 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                 return -EINVAL;
 130         }
 131
 132         vsid = map->host_vsid;
 133         va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);
 134
 135         if (!orig_pte->may_write)
 136                 rflags |= HPTE_R_PP;
 137         else
 138                 mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 139
 140         if (!orig_pte->may_execute)
 141                 rflags |= HPTE_R_N;
 142
 143         hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);
 144
 145 map_again:
 146         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 147
 148         /* In case we tried normal mapping already, let's nuke old entries */
 149         if (attempt > 1)
 150                 if (ppc_md.hpte_remove(hpteg) < 0)
 151                         return -1;
 152
 153         ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);
 154
 155         if (ret < 0) {
 156                 /* If we couldn't map a primary PTE, try a secondary */
 157                 hash = ~hash;
 158                 vflags ^= HPTE_V_SECONDARY;
 159                 attempt++;
 160                 goto map_again;
 161         } else {
 162                 struct hpte_cache *pte = kvmppc_mmu_hpte_cache_next(vcpu);
 163
 164                 dprintk_mmu("KVM: %c%c Map 0x%lx: [%lx] 0x%lx (0x%llx) -> %lx\n",
 165                             ((rflags & HPTE_R_PP) == 3) ? '-' : 'w',
 166                             (rflags & HPTE_R_N) ? '-' : 'x',
 167                             orig_pte->eaddr, hpteg, va, orig_pte->vpage, hpaddr);
 168
 169                 /* The ppc_md code may give us a secondary entry even though we
 170                    asked for a primary. Fix up. */
 171                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 172                         hash = ~hash;
 173                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 174                 }
 175
 176                 pte->slot = hpteg + (ret & 7);
 177                 pte->host_va = va;
 178                 pte->pte = *orig_pte;
 179                 pte->pfn = hpaddr >> PAGE_SHIFT;
 180
 181                 kvmppc_mmu_hpte_cache_map(vcpu, pte);
 182         }
 183
 184         return 0;
 185 }
 186
 187 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 188 {
 189         struct kvmppc_sid_map *map;
 190         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 191         u16 sid_map_mask;
 192         static int backwards_map = 0;
 193
 194         if (vcpu->arch.msr & MSR_PR)
 195                 gvsid |= VSID_PR;
 196
 197         /* We might get collisions that trap in preceding order, so let's
 198            map them differently */
 199
 200         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 201         if (backwards_map)
 202                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 203
 204         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 205
 206         /* Make sure we're taking the other map next time */
 207         backwards_map = !backwards_map;
 208
 209         /* Uh-oh ... out of mappings. Let's flush! */
 210         if (vcpu_book3s->vsid_next == vcpu_book3s->vsid_max) {
 211                 vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
 212                 memset(vcpu_book3s->sid_map, 0,
 213                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 214                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 215                 kvmppc_mmu_flush_segments(vcpu);
 216         }
 217         map->host_vsid = vcpu_book3s->vsid_next++;
 218
 219         map->guest_vsid = gvsid;
 220         map->valid = true;
 221
 222         dprintk_slb("SLB: New mapping at %d: 0x%llx -> 0x%llx\n",
 223                     sid_map_mask, gvsid, map->host_vsid);
 224
 225         return map;
 226 }
 227
 228 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 229 {
 230         int i;
 231         int max_slb_size = 64;
 232         int found_inval = -1;
 233         int r;
 234
 235         if (!to_svcpu(vcpu)->slb_max)
 236                 to_svcpu(vcpu)->slb_max = 1;
 237
 238         /* Are we overwriting? */
 239         for (i = 1; i < to_svcpu(vcpu)->slb_max; i++) {
 240                 if (!(to_svcpu(vcpu)->slb[i].esid & SLB_ESID_V))
 241                         found_inval = i;
 242                 else if ((to_svcpu(vcpu)->slb[i].esid & ESID_MASK) == esid)
 243                         return i;
 244         }
 245
 246         /* Found a spare entry that was invalidated before */
 247         if (found_inval > 0)
 248                 return found_inval;
 249
 250         /* No spare invalid entry, so create one */
 251
 252         if (mmu_slb_size < 64)
 253                 max_slb_size = mmu_slb_size;
 254
 255         /* Overflowing -> purge */
 256         if ((to_svcpu(vcpu)->slb_max) == max_slb_size)
 257                 kvmppc_mmu_flush_segments(vcpu);
 258
 259         r = to_svcpu(vcpu)->slb_max;
 260         to_svcpu(vcpu)->slb_max++;
 261
 262         return r;
 263 }
 264
 265 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 266 {
 267         u64 esid = eaddr >> SID_SHIFT;
 268         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 269         u64 slb_vsid = SLB_VSID_USER;
 270         u64 gvsid;
 271         int slb_index;
 272         struct kvmppc_sid_map *map;
 273
 274         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 275
 276         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 277                 /* Invalidate an entry */
 278                 to_svcpu(vcpu)->slb[slb_index].esid = 0;
 279                 return -ENOENT;
 280         }
 281
 282         map = find_sid_vsid(vcpu, gvsid);
 283         if (!map)
 284                 map = create_sid_map(vcpu, gvsid);
 285
 286         map->guest_esid = esid;
 287
 288         slb_vsid |= (map->host_vsid << 12);
 289         slb_vsid &= ~SLB_VSID_KP;
 290         slb_esid |= slb_index;
 291
 292         to_svcpu(vcpu)->slb[slb_index].esid = slb_esid;
 293         to_svcpu(vcpu)->slb[slb_index].vsid = slb_vsid;
 294
 295         dprintk_slb("slbmte %#llx, %#llx\n", slb_vsid, slb_esid);
 296
 297         return 0;
 298 }
 299
 300 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 301 {
 302         to_svcpu(vcpu)->slb_max = 1;
 303         to_svcpu(vcpu)->slb[0].esid = 0;
 304 }
 305
 306 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 307 {
 308         kvmppc_mmu_hpte_destroy(vcpu);
 309         __destroy_context(to_book3s(vcpu)->context_id);
 310 }
 311
 312 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 313 {
 314         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 315         int err;
 316
 317         err = __init_new_context();
 318         if (err < 0)
 319                 return -1;
 320         vcpu3s->context_id = err;
 321
 322         vcpu3s->vsid_max = ((vcpu3s->context_id + 1) << USER_ESID_BITS) - 1;
 323         vcpu3s->vsid_first = vcpu3s->context_id << USER_ESID_BITS;
 324         vcpu3s->vsid_next = vcpu3s->vsid_first;
 325
 326         kvmppc_mmu_hpte_init(vcpu);
 327
 328         return 0;
 329 }