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
  92         /* Get host physical address for gpa */
  93         hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
  94         if (is_error_pfn(hpaddr)) {
  95                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
  96                 return -EINVAL;
  97         }
  98         hpaddr <<= PAGE_SHIFT;
  99         hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 100
 101         /* and write the mapping ea -> hpa into the pt */
 102         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 103         map = find_sid_vsid(vcpu, vsid);
 104         if (!map) {
 105                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 106                 WARN_ON(ret < 0);
 107                 map = find_sid_vsid(vcpu, vsid);
 108         }
 109         if (!map) {
 110                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 111                                 vsid, orig_pte->eaddr);
 112                 WARN_ON(true);
 113                 return -EINVAL;
 114         }
 115
 116         vsid = map->host_vsid;
 117         va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);
 118
 119         if (!orig_pte->may_write)
 120                 rflags |= HPTE_R_PP;
 121         else
 122                 mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 123
 124         if (!orig_pte->may_execute)
 125                 rflags |= HPTE_R_N;
 126
 127         hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);
 128
 129 map_again:
 130         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 131
 132         /* In case we tried normal mapping already, let's nuke old entries */
 133         if (attempt > 1)
 134                 if (ppc_md.hpte_remove(hpteg) < 0)
 135                         return -1;
 136
 137         ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);
 138
 139         if (ret < 0) {
 140                 /* If we couldn't map a primary PTE, try a secondary */
 141                 hash = ~hash;
 142                 vflags ^= HPTE_V_SECONDARY;
 143                 attempt++;
 144                 goto map_again;
 145         } else {
 146                 struct hpte_cache *pte = kvmppc_mmu_hpte_cache_next(vcpu);
 147
 148                 trace_kvm_book3s_64_mmu_map(rflags, hpteg, va, hpaddr, orig_pte);
 149
 150                 /* The ppc_md code may give us a secondary entry even though we
 151                    asked for a primary. Fix up. */
 152                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 153                         hash = ~hash;
 154                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 155                 }
 156
 157                 pte->slot = hpteg + (ret & 7);
 158                 pte->host_va = va;
 159                 pte->pte = *orig_pte;
 160                 pte->pfn = hpaddr >> PAGE_SHIFT;
 161
 162                 kvmppc_mmu_hpte_cache_map(vcpu, pte);
 163         }
 164
 165         return 0;
 166 }
 167
 168 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 169 {
 170         struct kvmppc_sid_map *map;
 171         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 172         u16 sid_map_mask;
 173         static int backwards_map = 0;
 174
 175         if (vcpu->arch.shared->msr & MSR_PR)
 176                 gvsid |= VSID_PR;
 177
 178         /* We might get collisions that trap in preceding order, so let's
 179            map them differently */
 180
 181         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 182         if (backwards_map)
 183                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 184
 185         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 186
 187         /* Make sure we're taking the other map next time */
 188         backwards_map = !backwards_map;
 189
 190         /* Uh-oh ... out of mappings. Let's flush! */
 191         if (vcpu_book3s->vsid_next == vcpu_book3s->vsid_max) {
 192                 vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
 193                 memset(vcpu_book3s->sid_map, 0,
 194                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 195                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 196                 kvmppc_mmu_flush_segments(vcpu);
 197         }
 198         map->host_vsid = vcpu_book3s->vsid_next++;
 199
 200         map->guest_vsid = gvsid;
 201         map->valid = true;
 202
 203         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 204
 205         return map;
 206 }
 207
 208 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 209 {
 210         int i;
 211         int max_slb_size = 64;
 212         int found_inval = -1;
 213         int r;
 214
 215         if (!to_svcpu(vcpu)->slb_max)
 216                 to_svcpu(vcpu)->slb_max = 1;
 217
 218         /* Are we overwriting? */
 219         for (i = 1; i < to_svcpu(vcpu)->slb_max; i++) {
 220                 if (!(to_svcpu(vcpu)->slb[i].esid & SLB_ESID_V))
 221                         found_inval = i;
 222                 else if ((to_svcpu(vcpu)->slb[i].esid & ESID_MASK) == esid)
 223                         return i;
 224         }
 225
 226         /* Found a spare entry that was invalidated before */
 227         if (found_inval > 0)
 228                 return found_inval;
 229
 230         /* No spare invalid entry, so create one */
 231
 232         if (mmu_slb_size < 64)
 233                 max_slb_size = mmu_slb_size;
 234
 235         /* Overflowing -> purge */
 236         if ((to_svcpu(vcpu)->slb_max) == max_slb_size)
 237                 kvmppc_mmu_flush_segments(vcpu);
 238
 239         r = to_svcpu(vcpu)->slb_max;
 240         to_svcpu(vcpu)->slb_max++;
 241
 242         return r;
 243 }
 244
 245 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 246 {
 247         u64 esid = eaddr >> SID_SHIFT;
 248         u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 249         u64 slb_vsid = SLB_VSID_USER;
 250         u64 gvsid;
 251         int slb_index;
 252         struct kvmppc_sid_map *map;
 253
 254         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 255
 256         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 257                 /* Invalidate an entry */
 258                 to_svcpu(vcpu)->slb[slb_index].esid = 0;
 259                 return -ENOENT;
 260         }
 261
 262         map = find_sid_vsid(vcpu, gvsid);
 263         if (!map)
 264                 map = create_sid_map(vcpu, gvsid);
 265
 266         map->guest_esid = esid;
 267
 268         slb_vsid |= (map->host_vsid << 12);
 269         slb_vsid &= ~SLB_VSID_KP;
 270         slb_esid |= slb_index;
 271
 272         to_svcpu(vcpu)->slb[slb_index].esid = slb_esid;
 273         to_svcpu(vcpu)->slb[slb_index].vsid = slb_vsid;
 274
 275         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 276
 277         return 0;
 278 }
 279
 280 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 281 {
 282         to_svcpu(vcpu)->slb_max = 1;
 283         to_svcpu(vcpu)->slb[0].esid = 0;
 284 }
 285
 286 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 287 {
 288         kvmppc_mmu_hpte_destroy(vcpu);
 289         __destroy_context(to_book3s(vcpu)->context_id[0]);
 290 }
 291
 292 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 293 {
 294         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 295         int err;
 296
 297         err = __init_new_context();
 298         if (err < 0)
 299                 return -1;
 300         vcpu3s->context_id[0] = err;
 301
 302         vcpu3s->vsid_max = ((vcpu3s->context_id[0] + 1) << USER_ESID_BITS) - 1;
 303         vcpu3s->vsid_first = vcpu3s->context_id[0] << USER_ESID_BITS;
 304         vcpu3s->vsid_next = vcpu3s->vsid_first;
 305
 306         kvmppc_mmu_hpte_init(vcpu);
 307
 308         return 0;
 309 }