release/src-rt-6.x.4708/linux/linux-2.6.36/arch/powerpc/kvm/book3s_32_mmu_host.c

   1 /*
   2  * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
   3  *
   4  * Authors:
   5  *     Alexander Graf <agraf@suse.de>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License, version 2, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  */
  20
  21 #include <linux/kvm_host.h>
  22 #include <linux/hash.h>
  23
  24 #include <asm/kvm_ppc.h>
  25 #include <asm/kvm_book3s.h>
  26 #include <asm/mmu-hash32.h>
  27 #include <asm/machdep.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/hw_irq.h>
  30
  31 /* #define DEBUG_MMU */
  32 /* #define DEBUG_SR */
  33
  34 #ifdef DEBUG_MMU
  35 #define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
  36 #else
  37 #define dprintk_mmu(a, ...) do { } while(0)
  38 #endif
  39
  40 #ifdef DEBUG_SR
  41 #define dprintk_sr(a, ...) printk(KERN_INFO a, __VA_ARGS__)
  42 #else
  43 #define dprintk_sr(a, ...) do { } while(0)
  44 #endif
  45
  46 #if PAGE_SHIFT != 12
  47 #error Unknown page size
  48 #endif
  49
  50 #ifdef CONFIG_SMP
  51 #error XXX need to grab mmu_hash_lock
  52 #endif
  53
  54 #ifdef CONFIG_PTE_64BIT
  55 #error Only 32 bit pages are supported for now
  56 #endif
  57
  58 static ulong htab;
  59 static u32 htabmask;
  60
  61 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  62 {
  63         volatile u32 *pteg;
  64
  65         /* Remove from host HTAB */
  66         pteg = (u32*)pte->slot;
  67         pteg[0] = 0;
  68
  69         /* And make sure it's gone from the TLB too */
  70         asm volatile ("sync");
  71         asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
  72         asm volatile ("sync");
  73         asm volatile ("tlbsync");
  74 }
  75
  76 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  77  * a hash, so we don't waste cycles on looping */
  78 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
  79 {
  80         return hash_64(gvsid, SID_MAP_BITS);
  81 }
  82
  83
  84 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
  85 {
  86         struct kvmppc_sid_map *map;
  87         u16 sid_map_mask;
  88
  89         if (vcpu->arch.msr & MSR_PR)
  90                 gvsid |= VSID_PR;
  91
  92         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
  93         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
  94         if (map->guest_vsid == gvsid) {
  95                 dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
  96                             gvsid, map->host_vsid);
  97                 return map;
  98         }
  99
 100         map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
 101         if (map->guest_vsid == gvsid) {
 102                 dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
 103                             gvsid, map->host_vsid);
 104                 return map;
 105         }
 106
 107         dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
 108         return NULL;
 109 }
 110
 111 static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
 112                                 bool primary)
 113 {
 114         u32 page, hash;
 115         ulong pteg = htab;
 116
 117         page = (eaddr & ~ESID_MASK) >> 12;
 118
 119         hash = ((vsid ^ page) << 6);
 120         if (!primary)
 121                 hash = ~hash;
 122
 123         hash &= htabmask;
 124
 125         pteg |= hash;
 126
 127         dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
 128                 htab, hash, htabmask, pteg);
 129
 130         return (u32*)pteg;
 131 }
 132
 133 extern char etext[];
 134
 135 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
 136 {
 137         pfn_t hpaddr;
 138         u64 va;
 139         u64 vsid;
 140         struct kvmppc_sid_map *map;
 141         volatile u32 *pteg;
 142         u32 eaddr = orig_pte->eaddr;
 143         u32 pteg0, pteg1;
 144         register int rr = 0;
 145         bool primary = false;
 146         bool evict = false;
 147         struct hpte_cache *pte;
 148
 149         /* Get host physical address for gpa */
 150         hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 151         if (kvm_is_error_hva(hpaddr)) {
 152                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
 153                                  orig_pte->eaddr);
 154                 return -EINVAL;
 155         }
 156         hpaddr <<= PAGE_SHIFT;
 157
 158         /* and write the mapping ea -> hpa into the pt */
 159         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 160         map = find_sid_vsid(vcpu, vsid);
 161         if (!map) {
 162                 kvmppc_mmu_map_segment(vcpu, eaddr);
 163                 map = find_sid_vsid(vcpu, vsid);
 164         }
 165         BUG_ON(!map);
 166
 167         vsid = map->host_vsid;
 168         va = (vsid << SID_SHIFT) | (eaddr & ~ESID_MASK);
 169
 170 next_pteg:
 171         if (rr == 16) {
 172                 primary = !primary;
 173                 evict = true;
 174                 rr = 0;
 175         }
 176
 177         pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
 178
 179         /* not evicting yet */
 180         if (!evict && (pteg[rr] & PTE_V)) {
 181                 rr += 2;
 182                 goto next_pteg;
 183         }
 184
 185         dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
 186         dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
 187         dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
 188         dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
 189         dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
 190         dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
 191         dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
 192         dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
 193         dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
 194
 195         pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
 196                 (primary ? 0 : PTE_SEC);
 197         pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
 198
 199         if (orig_pte->may_write) {
 200                 pteg1 |= PP_RWRW;
 201                 mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 202         } else {
 203                 pteg1 |= PP_RWRX;
 204         }
 205
 206         local_irq_disable();
 207
 208         if (pteg[rr]) {
 209                 pteg[rr] = 0;
 210                 asm volatile ("sync");
 211         }
 212         pteg[rr + 1] = pteg1;
 213         pteg[rr] = pteg0;
 214         asm volatile ("sync");
 215
 216         local_irq_enable();
 217
 218         dprintk_mmu("KVM: new PTEG: %p\n", pteg);
 219         dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
 220         dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
 221         dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
 222         dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
 223         dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
 224         dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
 225         dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
 226         dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
 227
 228
 229         /* Now tell our Shadow PTE code about the new page */
 230
 231         pte = kvmppc_mmu_hpte_cache_next(vcpu);
 232
 233         dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
 234                     orig_pte->may_write ? 'w' : '-',
 235                     orig_pte->may_execute ? 'x' : '-',
 236                     orig_pte->eaddr, (ulong)pteg, va,
 237                     orig_pte->vpage, hpaddr);
 238
 239         pte->slot = (ulong)&pteg[rr];
 240         pte->host_va = va;
 241         pte->pte = *orig_pte;
 242         pte->pfn = hpaddr >> PAGE_SHIFT;
 243
 244         kvmppc_mmu_hpte_cache_map(vcpu, pte);
 245
 246         return 0;
 247 }
 248
 249 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 250 {
 251         struct kvmppc_sid_map *map;
 252         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 253         u16 sid_map_mask;
 254         static int backwards_map = 0;
 255
 256         if (vcpu->arch.msr & MSR_PR)
 257                 gvsid |= VSID_PR;
 258
 259         /* We might get collisions that trap in preceding order, so let's
 260            map them differently */
 261
 262         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 263         if (backwards_map)
 264                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 265
 266         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 267
 268         /* Make sure we're taking the other map next time */
 269         backwards_map = !backwards_map;
 270
 271         /* Uh-oh ... out of mappings. Let's flush! */
 272         if (vcpu_book3s->vsid_next >= vcpu_book3s->vsid_max) {
 273                 vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
 274                 memset(vcpu_book3s->sid_map, 0,
 275                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 276                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 277                 kvmppc_mmu_flush_segments(vcpu);
 278         }
 279         map->host_vsid = vcpu_book3s->vsid_next;
 280
 281         /* Would have to be 111 to be completely aligned with the rest of
 282            Linux, but that is just way too little space! */
 283         vcpu_book3s->vsid_next+=1;
 284
 285         map->guest_vsid = gvsid;
 286         map->valid = true;
 287
 288         return map;
 289 }
 290
 291 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 292 {
 293         u32 esid = eaddr >> SID_SHIFT;
 294         u64 gvsid;
 295         u32 sr;
 296         struct kvmppc_sid_map *map;
 297         struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);
 298
 299         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 300                 /* Invalidate an entry */
 301                 svcpu->sr[esid] = SR_INVALID;
 302                 return -ENOENT;
 303         }
 304
 305         map = find_sid_vsid(vcpu, gvsid);
 306         if (!map)
 307                 map = create_sid_map(vcpu, gvsid);
 308
 309         map->guest_esid = esid;
 310         sr = map->host_vsid | SR_KP;
 311         svcpu->sr[esid] = sr;
 312
 313         dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
 314
 315         return 0;
 316 }
 317
 318 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 319 {
 320         int i;
 321         struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);
 322
 323         dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
 324         for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
 325                 svcpu->sr[i] = SR_INVALID;
 326 }
 327
 328 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 329 {
 330         kvmppc_mmu_hpte_destroy(vcpu);
 331         preempt_disable();
 332         __destroy_context(to_book3s(vcpu)->context_id);
 333         preempt_enable();
 334 }
 335
 336 /* From mm/mmu_context_hash32.c */
 337 #define CTX_TO_VSID(ctx) (((ctx) * (897 * 16)) & 0xffffff)
 338
 339 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 340 {
 341         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 342         int err;
 343         ulong sdr1;
 344
 345         err = __init_new_context();
 346         if (err < 0)
 347                 return -1;
 348         vcpu3s->context_id = err;
 349
 350         vcpu3s->vsid_max = CTX_TO_VSID(vcpu3s->context_id + 1) - 1;
 351         vcpu3s->vsid_first = CTX_TO_VSID(vcpu3s->context_id);
 352
 353         BUG_ON(vcpu3s->vsid_max < vcpu3s->vsid_first);
 354
 355         vcpu3s->vsid_next = vcpu3s->vsid_first;
 356
 357         /* Remember where the HTAB is */
 358         asm ( "mfsdr1 %0" : "=r"(sdr1) );
 359         htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
 360         htab = (ulong)__va(sdr1 & 0xffff0000);
 361
 362         kvmppc_mmu_hpte_init(vcpu);
 363
 364         return 0;
 365 }