LXR linux/arch/powerpc/kvm/book3s_64_mmu

   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_pr.h"
  31
  32#define PTE_SIZE 12
  33
  34void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  35{
  36        ppc_md.hpte_invalidate(pte->slot, pte->host_vpn,
  37                               pte->pagesize, pte->pagesize, 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 */
  43static 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
  56static 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
  81int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
  82                        bool iswrite)
  83{
  84        unsigned long vpn;
  85        pfn_t hpaddr;
  86        ulong hash, hpteg;
  87        u64 vsid;
  88        int ret;
  89        int rflags = 0x192;
  90        int vflags = 0;
  91        int attempt = 0;
  92        struct kvmppc_sid_map *map;
  93        int r = 0;
  94        int hpsize = MMU_PAGE_4K;
  95        bool writable;
  96        unsigned long mmu_seq;
  97        struct kvm *kvm = vcpu->kvm;
  98        struct hpte_cache *cpte;
  99        unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
 100        unsigned long pfn;
 101
 102        /* used to check for invalidations in progress */
 103        mmu_seq = kvm->mmu_notifier_seq;
 104        smp_rmb();
 105
 106        /* Get host physical address for gpa */
 107        pfn = kvmppc_gfn_to_pfn(vcpu, gfn, iswrite, &writable);
 108        if (is_error_noslot_pfn(pfn)) {
 109                printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n", gfn);
 110                r = -EINVAL;
 111                goto out;
 112        }
 113        hpaddr = pfn << PAGE_SHIFT;
 114
 115        /* and write the mapping ea -> hpa into the pt */
 116        vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 117        map = find_sid_vsid(vcpu, vsid);
 118        if (!map) {
 119                ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 120                WARN_ON(ret < 0);
 121                map = find_sid_vsid(vcpu, vsid);
 122        }
 123        if (!map) {
 124                printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 125                                vsid, orig_pte->eaddr);
 126                WARN_ON(true);
 127                r = -EINVAL;
 128                goto out;
 129        }
 130
 131        vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
 132
 133        kvm_set_pfn_accessed(pfn);
 134        if (!orig_pte->may_write || !writable)
 135                rflags |= PP_RXRX;
 136        else {
 137                mark_page_dirty(vcpu->kvm, gfn);
 138                kvm_set_pfn_dirty(pfn);
 139        }
 140
 141        if (!orig_pte->may_execute)
 142                rflags |= HPTE_R_N;
 143        else
 144                kvmppc_mmu_flush_icache(pfn);
 145
 146        /*
 147         * Use 64K pages if possible; otherwise, on 64K page kernels,
 148         * we need to transfer 4 more bits from guest real to host real addr.
 149         */
 150        if (vsid & VSID_64K)
 151                hpsize = MMU_PAGE_64K;
 152        else
 153                hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 154
 155        hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
 156
 157        cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 158
 159        spin_lock(&kvm->mmu_lock);
 160        if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
 161                r = -EAGAIN;
 162                goto out_unlock;
 163        }
 164
 165map_again:
 166        hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 167
 168        /* In case we tried normal mapping already, let's nuke old entries */
 169        if (attempt > 1)
 170                if (ppc_md.hpte_remove(hpteg) < 0) {
 171                        r = -1;
 172                        goto out_unlock;
 173                }
 174
 175        ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 176                                 hpsize, hpsize, MMU_SEGSIZE_256M);
 177
 178        if (ret < 0) {
 179                /* If we couldn't map a primary PTE, try a secondary */
 180                hash = ~hash;
 181                vflags ^= HPTE_V_SECONDARY;
 182                attempt++;
 183                goto map_again;
 184        } else {
 185                trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 186                                            vpn, hpaddr, orig_pte);
 187
 188                /* The ppc_md code may give us a secondary entry even though we
 189                   asked for a primary. Fix up. */
 190                if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 191                        hash = ~hash;
 192                        hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 193                }
 194
 195                cpte->slot = hpteg + (ret & 7);
 196                cpte->host_vpn = vpn;
 197                cpte->pte = *orig_pte;
 198                cpte->pfn = pfn;
 199                cpte->pagesize = hpsize;
 200
 201                kvmppc_mmu_hpte_cache_map(vcpu, cpte);
 202                cpte = NULL;
 203        }
 204
 205out_unlock:
 206        spin_unlock(&kvm->mmu_lock);
 207        kvm_release_pfn_clean(pfn);
 208        if (cpte)
 209                kvmppc_mmu_hpte_cache_free(cpte);
 210
 211out:
 212        return r;
 213}
 214
 215void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 216{
 217        u64 mask = 0xfffffffffULL;
 218        u64 vsid;
 219
 220        vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
 221        if (vsid & VSID_64K)
 222                mask = 0xffffffff0ULL;
 223        kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
 224}
 225
 226static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 227{
 228        struct kvmppc_sid_map *map;
 229        struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 230        u16 sid_map_mask;
 231        static int backwards_map = 0;
 232
 233        if (vcpu->arch.shared->msr & MSR_PR)
 234                gvsid |= VSID_PR;
 235
 236        /* We might get collisions that trap in preceding order, so let's
 237           map them differently */
 238
 239        sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 240        if (backwards_map)
 241                sid_map_mask = SID_MAP_MASK - sid_map_mask;
 242
 243        map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 244
 245        /* Make sure we're taking the other map next time */
 246        backwards_map = !backwards_map;
 247
 248        /* Uh-oh ... out of mappings. Let's flush! */
 249        if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 250                vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 251                memset(vcpu_book3s->sid_map, 0,
 252                       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 253                kvmppc_mmu_pte_flush(vcpu, 0, 0);
 254                kvmppc_mmu_flush_segments(vcpu);
 255        }
 256        map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
 257
 258        map->guest_vsid = gvsid;
 259        map->valid = true;
 260
 261        trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 262
 263        return map;
 264}
 265
 266static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 267{
 268        struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 269        int i;
 270        int max_slb_size = 64;
 271        int found_inval = -1;
 272        int r;
 273
 274        if (!svcpu->slb_max)
 275                svcpu->slb_max = 1;
 276
 277        /* Are we overwriting? */
 278        for (i = 1; i < svcpu->slb_max; i++) {
 279                if (!(svcpu->slb[i].esid & SLB_ESID_V))
 280                        found_inval = i;
 281                else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
 282                        r = i;
 283                        goto out;
 284                }
 285        }
 286
 287        /* Found a spare entry that was invalidated before */
 288        if (found_inval > 0) {
 289                r = found_inval;
 290                goto out;
 291        }
 292
 293        /* No spare invalid entry, so create one */
 294
 295        if (mmu_slb_size < 64)
 296                max_slb_size = mmu_slb_size;
 297
 298        /* Overflowing -> purge */
 299        if ((svcpu->slb_max) == max_slb_size)
 300                kvmppc_mmu_flush_segments(vcpu);
 301
 302        r = svcpu->slb_max;
 303        svcpu->slb_max++;
 304
 305out:
 306        svcpu_put(svcpu);
 307        return r;
 308}
 309
 310int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
 311{
 312        struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 313        u64 esid = eaddr >> SID_SHIFT;
 314        u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
 315        u64 slb_vsid = SLB_VSID_USER;
 316        u64 gvsid;
 317        int slb_index;
 318        struct kvmppc_sid_map *map;
 319        int r = 0;
 320
 321        slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
 322
 323        if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
 324                /* Invalidate an entry */
 325                svcpu->slb[slb_index].esid = 0;
 326                r = -ENOENT;
 327                goto out;
 328        }
 329
 330        map = find_sid_vsid(vcpu, gvsid);
 331        if (!map)
 332                map = create_sid_map(vcpu, gvsid);
 333
 334        map->guest_esid = esid;
 335
 336        slb_vsid |= (map->host_vsid << 12);
 337        slb_vsid &= ~SLB_VSID_KP;
 338        slb_esid |= slb_index;
 339
 340#ifdef CONFIG_PPC_64K_PAGES
 341        /* Set host segment base page size to 64K if possible */
 342        if (gvsid & VSID_64K)
 343                slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
 344#endif
 345
 346        svcpu->slb[slb_index].esid = slb_esid;
 347        svcpu->slb[slb_index].vsid = slb_vsid;
 348
 349        trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
 350
 351out:
 352        svcpu_put(svcpu);
 353        return r;
 354}
 355
 356void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
 357{
 358        struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 359        ulong seg_mask = -seg_size;
 360        int i;
 361
 362        for (i = 1; i < svcpu->slb_max; i++) {
 363                if ((svcpu->slb[i].esid & SLB_ESID_V) &&
 364                    (svcpu->slb[i].esid & seg_mask) == ea) {
 365                        /* Invalidate this entry */
 366                        svcpu->slb[i].esid = 0;
 367                }
 368        }
 369
 370        svcpu_put(svcpu);
 371}
 372
 373void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 374{
 375        struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 376        svcpu->slb_max = 1;
 377        svcpu->slb[0].esid = 0;
 378        svcpu_put(svcpu);
 379}
 380
 381void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
 382{
 383        kvmppc_mmu_hpte_destroy(vcpu);
 384        __destroy_context(to_book3s(vcpu)->context_id[0]);
 385}
 386
 387int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 388{
 389        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 390        int err;
 391
 392        err = __init_new_context();
 393        if (err < 0)
 394                return -1;
 395        vcpu3s->context_id[0] = err;
 396
 397        vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 398                                  << ESID_BITS) - 1;
 399        vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 400        vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 401
 402        kvmppc_mmu_hpte_init(vcpu);
 403
 404        return 0;
 405}
 406