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.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_va,
  37                                MMU_PAGE_4K, 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 {
  83         pfn_t hpaddr;
  84         ulong hash, hpteg, va;
  85         u64 vsid;
  86         int ret;
  87         int rflags = 0x192;
  88         int vflags = 0;
  89         int attempt = 0;
  90         struct kvmppc_sid_map *map;
  91         int r = 0;
  92
  93         /* Get host physical address for gpa */
  94         hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
  95         if (is_error_pfn(hpaddr)) {
  96                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
  97                 r = -EINVAL;
  98                 goto out;
  99         }
 100         hpaddr <<= PAGE_SHIFT;
 101         hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 102
 103         /* and write the mapping ea -> hpa into the pt */
 104         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 105         map = find_sid_vsid(vcpu, vsid);
 106         if (!map) {
 107                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 108                 WARN_ON(ret < 0);
 109                 map = find_sid_vsid(vcpu, vsid);
 110         }
 111         if (!map) {
 112                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 113                                 vsid, orig_pte->eaddr);
 114                 WARN_ON(true);
 115                 r = -EINVAL;
 116                 goto out;
 117         }
 118
 119         vsid = map->host_vsid;
 120         va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);
 121
 122         if (!orig_pte->may_write)
 123                 rflags |= HPTE_R_PP;
 124         else
 125                 mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 126
 127         if (!orig_pte->may_execute)
 128                 rflags |= HPTE_R_N;
 129
 130         hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);
 131
 132 map_again:
 133         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 134
 135         /* In case we tried normal mapping already, let's nuke old entries */
 136         if (attempt > 1)
 137                 if (ppc_md.hpte_remove(hpteg) < 0) {
 138                         r = -1;
 139                         goto out;
 140                 }
 141
 142         ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);
 143
 144         if (ret < 0) {
 145                 /* If we couldn't map a primary PTE, try a secondary */
 146                 hash = ~hash;
 147                 vflags ^= HPTE_V_SECONDARY;
 148                 attempt++;
 149                 goto map_again;
 150         } else {
 151                 struct hpte_cache *pte = kvmppc_mmu_hpte_cache_next(vcpu);
 152
 153                 trace_kvm_book3s_64_mmu_map(rflags, hpteg, va, hpaddr, orig_pte);
 154
 155                 /* The ppc_md code may give us a secondary entry even though we
 156                    asked for a primary. Fix up. */
 157                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 158                         hash = ~hash;
 159                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 160                 }
 161
 162                 pte->slot = hpteg + (ret & 7);
 163                 pte->host_va = va;
 164                 pte->pte = *orig_pte;
 165                 pte->pfn = hpaddr >> PAGE_SHIFT;
 166
 167                 kvmppc_mmu_hpte_cache_map(vcpu, pte);
 168         }
 169
 170 out:
 171         return r;
 172 }
 173
 174 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 175 {
 176         struct kvmppc_sid_map *map;
 177         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 178         u16 sid_map_mask;
 179         static int backwards_map = 0;
 180
 181         if (vcpu->arch.shared->msr & MSR_PR)
 182                 gvsid |= VSID_PR;
 183
 184         /* We might get collisions that trap in preceding order, so let's
 185            map them differently */
 186
 187         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 188         if (backwards_map)
 189                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 190
 191         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 192
 193         /* Make sure we're taking the other map next time */
 194         backwards_map = !backwards_map;
 195
 196         /* Uh-oh ... out of mappings. Let's flush! */
 197         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 198                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 199                 memset(vcpu_book3s->sid_map, 0,
 200                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 201                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 202                 kvmppc_mmu_flush_segments(vcpu);
 203         }
 204         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 205
 206         map->guest_vsid = gvsid;
 207         map->valid = true;
 208
 209         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 210
 211         return map;
 212 }
 213
 214 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 215 {
 216         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 217         int i;
 218         int max_slb_size = 64;
 219         int found_inval = -1;
 220         int r;
 221
 222         if (!svcpu->slb_max)
 223                 svcpu->slb_max = 1;
 224
 225         /* Are we overwriting? */
 226         for (i = 1; i < svcpu->slb_max; i++) {
 227                 if (!(svcpu->slb[i].esid & SLB_ESID_V))
 228                         found_inval = i;
 229                 else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 230                         r = i;
 231                         goto out;
 232                 }
 233         }
 234
 235         /* Found a spare entry that was invalidated before */
 236         if (found_inval > 0) {
 237                 r = found_inval;
 238                 goto out;
 239         }
 240
 241         /* No spare invalid entry, so create one */
 242
 243         if (mmu_slb_size < 64)
 244                 max_slb_size = mmu_slb_size;
 245
 246         /* Overflowing -> purge */
 247         if ((svcpu->slb_max) == max_slb_size)
 248                 kvmppc_mmu_flush_segments(vcpu);
 249
 250         r = svcpu->slb_max;
 251         svcpu->slb_max++;
 252
 253 out:
 254         svcpu_put(svcpu);
 255         return r;
 256 }
 257
 258 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 259 {
 260         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 261         u64 esid = eaddr >> SID_SHIFT;
 262         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 263         u64 slb_vsid = SLB_VSID_USER;
 264         u64 gvsid;
 265         int slb_index;
 266         struct kvmppc_sid_map *map;
 267         int r = 0;
 268
 269         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 270
 271         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 272                 /* Invalidate an entry */
 273                 svcpu->slb[slb_index].esid = 0;
 274                 r = -ENOENT;
 275                 goto out;
 276         }
 277
 278         map = find_sid_vsid(vcpu, gvsid);
 279         if (!map)
 280                 map = create_sid_map(vcpu, gvsid);
 281
 282         map->guest_esid = esid;
 283
 284         slb_vsid |= (map->host_vsid << 12);
 285         slb_vsid &= ~SLB_VSID_KP;
 286         slb_esid |= slb_index;
 287
 288         svcpu->slb[slb_index].esid = slb_esid;
 289         svcpu->slb[slb_index].vsid = slb_vsid;
 290
 291         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 292
 293 out:
 294         svcpu_put(svcpu);
 295         return r;
 296 }
 297
 298 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 299 {
 300         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 301         svcpu->slb_max = 1;
 302         svcpu->slb[0].esid = 0;
 303         svcpu_put(svcpu);
 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[0]);
 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[0] = err;
 321
 322         vcpu3s->proto_vsid_max = ((vcpu3s->context_id[0] + 1)
 323                                   << USER_ESID_BITS) - 1;
 324         vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
 325         vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 326
 327         kvmppc_mmu_hpte_init(vcpu);
 328
 329         return 0;
 330 }