arch/powerpc/kvm/book3s_64_mmu_host.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
   4  *
   5  * Authors:
   6  *     Alexander Graf <agraf@suse.de>
   7  *     Kevin Wolf <mail@kevin-wolf.de>
   8  */
   9
  10 #include <linux/kvm_host.h>
  11
  12 #include <asm/kvm_ppc.h>
  13 #include <asm/kvm_book3s.h>
  14 #include <asm/book3s/64/mmu-hash.h>
  15 #include <asm/machdep.h>
  16 #include <asm/mmu_context.h>
  17 #include <asm/hw_irq.h>
  18 #include "trace_pr.h"
  19 #include "book3s.h"
  20
  21 #define PTE_SIZE 12
  22
  23 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
  24 {
  25         mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
  26                                      pte->pagesize, pte->pagesize,
  27                                      MMU_SEGSIZE_256M, false);
  28 }
  29
  30 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
  31  * a hash, so we don't waste cycles on looping */
  32 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
  33 {
  34         return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
  35                      ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
  36                      ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
  37                      ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
  38                      ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
  39                      ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
  40                      ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
  41                      ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
  42 }
  43
  44
  45 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
  46 {
  47         struct kvmppc_sid_map *map;
  48         u16 sid_map_mask;
  49
  50         if (kvmppc_get_msr(vcpu) & MSR_PR)
  51                 gvsid |= VSID_PR;
  52
  53         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
  54         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
  55         if (map->valid && (map->guest_vsid == gvsid)) {
  56                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  57                 return map;
  58         }
  59
  60         map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
  61         if (map->valid && (map->guest_vsid == gvsid)) {
  62                 trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
  63                 return map;
  64         }
  65
  66         trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
  67         return NULL;
  68 }
  69
  70 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
  71                         bool iswrite)
  72 {
  73         unsigned long vpn;
  74         kvm_pfn_t hpaddr;
  75         ulong hash, hpteg;
  76         u64 vsid;
  77         int ret;
  78         int rflags = 0x192;
  79         int vflags = 0;
  80         int attempt = 0;
  81         struct kvmppc_sid_map *map;
  82         int r = 0;
  83         int hpsize = MMU_PAGE_4K;
  84         bool writable;
  85         unsigned long mmu_seq;
  86         struct kvm *kvm = vcpu->kvm;
  87         struct hpte_cache *cpte;
  88         unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
  89         unsigned long pfn;
  90
  91         /* used to check for invalidations in progress */
  92         mmu_seq = kvm->mmu_notifier_seq;
  93         smp_rmb();
  94
  95         /* Get host physical address for gpa */
  96         pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
  97         if (is_error_noslot_pfn(pfn)) {
  98                 printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
  99                        orig_pte->raddr);
 100                 r = -EINVAL;
 101                 goto out;
 102         }
 103         hpaddr = pfn << PAGE_SHIFT;
 104
 105         /* and write the mapping ea -> hpa into the pt */
 106         vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
 107         map = find_sid_vsid(vcpu, vsid);
 108         if (!map) {
 109                 ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
 110                 WARN_ON(ret < 0);
 111                 map = find_sid_vsid(vcpu, vsid);
 112         }
 113         if (!map) {
 114                 printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
 115                                 vsid, orig_pte->eaddr);
 116                 WARN_ON(true);
 117                 r = -EINVAL;
 118                 goto out;
 119         }
 120
 121         vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
 122
 123         kvm_set_pfn_accessed(pfn);
 124         if (!orig_pte->may_write || !writable)
 125                 rflags |= PP_RXRX;
 126         else {
 127                 mark_page_dirty(vcpu->kvm, gfn);
 128                 kvm_set_pfn_dirty(pfn);
 129         }
 130
 131         if (!orig_pte->may_execute)
 132                 rflags |= HPTE_R_N;
 133         else
 134                 kvmppc_mmu_flush_icache(pfn);
 135
 136         rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
 137
 138         /*
 139          * Use 64K pages if possible; otherwise, on 64K page kernels,
 140          * we need to transfer 4 more bits from guest real to host real addr.
 141          */
 142         if (vsid & VSID_64K)
 143                 hpsize = MMU_PAGE_64K;
 144         else
 145                 hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
 146
 147         hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
 148
 149         cpte = kvmppc_mmu_hpte_cache_next(vcpu);
 150
 151         spin_lock(&kvm->mmu_lock);
 152         if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
 153                 r = -EAGAIN;
 154                 goto out_unlock;
 155         }
 156
 157 map_again:
 158         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 159
 160         /* In case we tried normal mapping already, let's nuke old entries */
 161         if (attempt > 1)
 162                 if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
 163                         r = -1;
 164                         goto out_unlock;
 165                 }
 166
 167         ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
 168                                        hpsize, hpsize, MMU_SEGSIZE_256M);
 169
 170         if (ret == -1) {
 171                 /* If we couldn't map a primary PTE, try a secondary */
 172                 hash = ~hash;
 173                 vflags ^= HPTE_V_SECONDARY;
 174                 attempt++;
 175                 goto map_again;
 176         } else if (ret < 0) {
 177                 r = -EIO;
 178                 goto out_unlock;
 179         } else {
 180                 trace_kvm_book3s_64_mmu_map(rflags, hpteg,
 181                                             vpn, hpaddr, orig_pte);
 182
 183                 /*
 184                  * The mmu_hash_ops code may give us a secondary entry even
 185                  * though we asked for a primary. Fix up.
 186                  */
 187                 if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
 188                         hash = ~hash;
 189                         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 190                 }
 191
 192                 cpte->slot = hpteg + (ret & 7);
 193                 cpte->host_vpn = vpn;
 194                 cpte->pte = *orig_pte;
 195                 cpte->pfn = pfn;
 196                 cpte->pagesize = hpsize;
 197
 198                 kvmppc_mmu_hpte_cache_map(vcpu, cpte);
 199                 cpte = NULL;
 200         }
 201
 202 out_unlock:
 203         spin_unlock(&kvm->mmu_lock);
 204         kvm_release_pfn_clean(pfn);
 205         if (cpte)
 206                 kvmppc_mmu_hpte_cache_free(cpte);
 207
 208 out:
 209         return r;
 210 }
 211
 212 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 213 {
 214         u64 mask = 0xfffffffffULL;
 215         u64 vsid;
 216
 217         vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
 218         if (vsid & VSID_64K)
 219                 mask = 0xffffffff0ULL;
 220         kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
 221 }
 222
 223 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
 224 {
 225         unsigned long vsid_bits = VSID_BITS_65_256M;
 226         struct kvmppc_sid_map *map;
 227         struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 228         u16 sid_map_mask;
 229         static int backwards_map = 0;
 230
 231         if (kvmppc_get_msr(vcpu) & MSR_PR)
 232                 gvsid |= VSID_PR;
 233
 234         /* We might get collisions that trap in preceding order, so let's
 235            map them differently */
 236
 237         sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
 238         if (backwards_map)
 239                 sid_map_mask = SID_MAP_MASK - sid_map_mask;
 240
 241         map = &to_book3s(vcpu)->sid_map[sid_map_mask];
 242
 243         /* Make sure we're taking the other map next time */
 244         backwards_map = !backwards_map;
 245
 246         /* Uh-oh ... out of mappings. Let's flush! */
 247         if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
 248                 vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
 249                 memset(vcpu_book3s->sid_map, 0,
 250                        sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
 251                 kvmppc_mmu_pte_flush(vcpu, 0, 0);
 252                 kvmppc_mmu_flush_segments(vcpu);
 253         }
 254
 255         if (mmu_has_feature(MMU_FTR_68_BIT_VA))
 256                 vsid_bits = VSID_BITS_256M;
 257
 258         map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
 259                                        VSID_MULTIPLIER_256M, vsid_bits);
 260
 261         map->guest_vsid = gvsid;
 262         map->valid = true;
 263
 264         trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
 265
 266         return map;
 267 }
 268
 269 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
 270 {
 271         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 272         int i;
 273         int max_slb_size = 64;
 274         int found_inval = -1;
 275         int r;
 276
 277         /* Are we overwriting? */
 278         for (i = 0; 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
 305 out:
 306         svcpu_put(svcpu);
 307         return r;
 308 }
 309
 310 int 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
 351 out:
 352         svcpu_put(svcpu);
 353         return r;
 354 }
 355
 356 void 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 = 0; 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
 373 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
 374 {
 375         struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
 376         svcpu->slb_max = 0;
 377         svcpu->slb[0].esid = 0;
 378         svcpu_put(svcpu);
 379 }
 380
 381 void 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
 387 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 388 {
 389         struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 390         int err;
 391
 392         err = hash__alloc_context_id();
 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 }