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_vpn,
  37                                MMU_PAGE_4K, 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         unsigned long vpn;
  84         pfn_t hpaddr;
  85         ulong hash, hpteg;
  86         u64 vsid;
  87         int ret;
  88         int rflags = 0x192;
  89         int vflags = 0;
  90         int attempt = 0;
  91         struct kvmppc_sid_map *map;
  92         int r = 0;
  93
  94         /* Get host physical address for gpa */
  95         hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
  96         if (is_error_noslot_pfn(hpaddr)) {
  97                 printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", orig_pte->eaddr);
  98                 r = -EINVAL;
  99                 goto out;
 100         }
 101         hpaddr <<= PAGE_SHIFT;
 102         hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 103
 104         /* and write the mapping ea -> hpa into the pt */
 105         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 106         map = find_sid_vsid(vcpu, vsid);
 107         if (!map) {
 108                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 109                 WARN_ON(ret < 0);
 110                 map = find_sid_vsid(vcpu, vsid);
 111         }
 112         if (!map) {
 113                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 114                                 vsid, orig_pte->eaddr);
 115                 WARN_ON(true);
 116                 r = -EINVAL;
 117                 goto out;
 118         }
 119
 120         vsid = map->host_vsid;
 121         vpn = hpt_vpn(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);
 122
 123         if (!orig_pte->may_write)
 124                 rflags |= HPTE_R_PP;
 125         else
 126                 mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
 127
 128         if (!orig_pte->may_execute)
 129                 rflags |= HPTE_R_N;
 130         else
 131                 kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);
 132
 133         hash = hpt_hash(vpn, PTE_SIZE, MMU_SEGSIZE_256M);
 134
 135 map_again:
 136         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 137
 138         /* In case we tried normal mapping already, let's nuke old entries */
 139         if (attempt > 1)
 140                 if (ppc_md.hpte_remove(hpteg) < 0) {
 141                         r = -1;
 142                         goto out;
 143                 }
 144
 145         ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 146                                  MMU_PAGE_4K, MMU_PAGE_4K, MMU_SEGSIZE_256M);
 147
 148         if (ret < 0) {
 149                 /* If we couldn't map a primary PTE, try a secondary */
 150                 hash = ~hash;
 151                 vflags ^= HPTE_V_SECONDARY;
 152                 attempt++;
 153                 goto map_again;
 154         } else {
 155                 struct hpte_cache *pte = kvmppc_mmu_hpte_cache_next(vcpu);
 156
 157                 trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 158                                             vpn, hpaddr, orig_pte);
 159
 160                 /* The ppc_md code may give us a secondary entry even though we
 161                    asked for a primary. Fix up. */
 162                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 163                         hash = ~hash;
 164                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 165                 }
 166
 167                 pte->slot = hpteg + (ret & 7);
 168                 pte->host_vpn = vpn;
 169                 pte->pte = *orig_pte;
 170                 pte->pfn = hpaddr >> PAGE_SHIFT;
 171
 172                 kvmppc_mmu_hpte_cache_map(vcpu, pte);
 173         }
 174         kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
 175
 176 out:
 177         return r;
 178 }
 179
 180 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 181 {
 182         struct kvmppc_sid_map *map;
 183         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 184         u16 sid_map_mask;
 185         static int backwards_map = 0;
 186
 187         if (vcpu->arch.shared->msr & MSR_PR)
 188                 gvsid |= VSID_PR;
 189
 190         /* We might get collisions that trap in preceding order, so let's
 191            map them differently */
 192
 193         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 194         if (backwards_map)
 195                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 196
 197         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 198
 199         /* Make sure we're taking the other map next time */
 200         backwards_map = !backwards_map;
 201
 202         /* Uh-oh ... out of mappings. Let's flush! */
 203         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 204                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 205                 memset(vcpu_book3s->sid_map, 0,
 206                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 207                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 208                 kvmppc_mmu_flush_segments(vcpu);
 209         }
 210         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 211
 212         map->guest_vsid = gvsid;
 213         map->valid = true;
 214
 215         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 216
 217         return map;
 218 }
 219
 220 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 221 {
 222         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 223         int i;
 224         int max_slb_size = 64;
 225         int found_inval = -1;
 226         int r;
 227
 228         if (!svcpu->slb_max)
 229                 svcpu->slb_max = 1;
 230
 231         /* Are we overwriting? */
 232         for (i = 1; i < svcpu->slb_max; i++) {
 233                 if (!(svcpu->slb[i].esid & SLB_ESID_V))
 234                         found_inval = i;
 235                 else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 236                         r = i;
 237                         goto out;
 238                 }
 239         }
 240
 241         /* Found a spare entry that was invalidated before */
 242         if (found_inval > 0) {
 243                 r = found_inval;
 244                 goto out;
 245         }
 246
 247         /* No spare invalid entry, so create one */
 248
 249         if (mmu_slb_size < 64)
 250                 max_slb_size = mmu_slb_size;
 251
 252         /* Overflowing -> purge */
 253         if ((svcpu->slb_max) == max_slb_size)
 254                 kvmppc_mmu_flush_segments(vcpu);
 255
 256         r = svcpu->slb_max;
 257         svcpu->slb_max++;
 258
 259 out:
 260         svcpu_put(svcpu);
 261         return r;
 262 }
 263
 264 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 265 {
 266         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 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         int r = 0;
 274
 275         slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 276
 277         if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 278                 /* Invalidate an entry */
 279                 svcpu->slb[slb_index].esid = 0;
 280                 r = -ENOENT;
 281                 goto out;
 282         }
 283
 284         map = find_sid_vsid(vcpu, gvsid);
 285         if (!map)
 286                 map = create_sid_map(vcpu, gvsid);
 287
 288         map->guest_esid = esid;
 289
 290         slb_vsid |= (map->host_vsid << 12);
 291         slb_vsid &= ~SLB_VSID_KP;
 292         slb_esid |= slb_index;
 293
 294         svcpu->slb[slb_index].esid = slb_esid;
 295         svcpu->slb[slb_index].vsid = slb_vsid;
 296
 297         trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 298
 299 out:
 300         svcpu_put(svcpu);
 301         return r;
 302 }
 303
 304 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
 305 {
 306         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 307         ulong seg_mask = -seg_size;
 308         int i;
 309
 310         for (i = 1; i < svcpu->slb_max; i++) {
 311                 if ((svcpu->slb[i].esid & SLB_ESID_V) &&
 312                     (svcpu->slb[i].esid & seg_mask) == ea) {
 313                         /* Invalidate this entry */
 314                         svcpu->slb[i].esid = 0;
 315                 }
 316         }
 317
 318         svcpu_put(svcpu);
 319 }
 320
 321 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 322 {
 323         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 324         svcpu->slb_max = 1;
 325         svcpu->slb[0].esid = 0;
 326         svcpu_put(svcpu);
 327 }
 328
 329 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
 330 {
 331         kvmppc_mmu_hpte_destroy(vcpu);
 332         __destroy_context(to_book3s(vcpu)->context_id[0]);
 333 }
 334
 335 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 336 {
 337         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 338         int err;
 339
 340         err = __init_new_context();
 341         if (err < 0)
 342                 return -1;
 343         vcpu3s->context_id[0] = err;
 344
 345         vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 346                                   << ESID_BITS) - 1;
 347         vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 348         vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 349
 350         kvmppc_mmu_hpte_init(vcpu);
 351
 352         return 0;
 353 }