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0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
0004  *
0005  * Authors:
0006  *     Alexander Graf <agraf@suse.de>
0007  *     Kevin Wolf <mail@kevin-wolf.de>
0008  */
0009 
0010 #include <linux/kvm_host.h>
0011 #include <linux/pkeys.h>
0012 
0013 #include <asm/kvm_ppc.h>
0014 #include <asm/kvm_book3s.h>
0015 #include <asm/book3s/64/mmu-hash.h>
0016 #include <asm/machdep.h>
0017 #include <asm/mmu_context.h>
0018 #include <asm/hw_irq.h>
0019 #include "trace_pr.h"
0020 #include "book3s.h"
0021 
0022 #define PTE_SIZE 12
0023 
0024 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
0025 {
0026     mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
0027                      pte->pagesize, pte->pagesize,
0028                      MMU_SEGSIZE_256M, false);
0029 }
0030 
0031 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
0032  * a hash, so we don't waste cycles on looping */
0033 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
0034 {
0035     return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
0036              ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
0037              ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
0038              ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
0039              ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
0040              ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
0041              ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
0042              ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
0043 }
0044 
0045 
0046 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
0047 {
0048     struct kvmppc_sid_map *map;
0049     u16 sid_map_mask;
0050 
0051     if (kvmppc_get_msr(vcpu) & MSR_PR)
0052         gvsid |= VSID_PR;
0053 
0054     sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
0055     map = &to_book3s(vcpu)->sid_map[sid_map_mask];
0056     if (map->valid && (map->guest_vsid == gvsid)) {
0057         trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
0058         return map;
0059     }
0060 
0061     map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
0062     if (map->valid && (map->guest_vsid == gvsid)) {
0063         trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
0064         return map;
0065     }
0066 
0067     trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
0068     return NULL;
0069 }
0070 
0071 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
0072             bool iswrite)
0073 {
0074     unsigned long vpn;
0075     kvm_pfn_t hpaddr;
0076     ulong hash, hpteg;
0077     u64 vsid;
0078     int ret;
0079     int rflags = 0x192;
0080     int vflags = 0;
0081     int attempt = 0;
0082     struct kvmppc_sid_map *map;
0083     int r = 0;
0084     int hpsize = MMU_PAGE_4K;
0085     bool writable;
0086     unsigned long mmu_seq;
0087     struct kvm *kvm = vcpu->kvm;
0088     struct hpte_cache *cpte;
0089     unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
0090     unsigned long pfn;
0091 
0092     /* used to check for invalidations in progress */
0093     mmu_seq = kvm->mmu_invalidate_seq;
0094     smp_rmb();
0095 
0096     /* Get host physical address for gpa */
0097     pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
0098     if (is_error_noslot_pfn(pfn)) {
0099         printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
0100                orig_pte->raddr);
0101         r = -EINVAL;
0102         goto out;
0103     }
0104     hpaddr = pfn << PAGE_SHIFT;
0105 
0106     /* and write the mapping ea -> hpa into the pt */
0107     vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
0108     map = find_sid_vsid(vcpu, vsid);
0109     if (!map) {
0110         ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
0111         WARN_ON(ret < 0);
0112         map = find_sid_vsid(vcpu, vsid);
0113     }
0114     if (!map) {
0115         printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
0116                 vsid, orig_pte->eaddr);
0117         WARN_ON(true);
0118         r = -EINVAL;
0119         goto out;
0120     }
0121 
0122     vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
0123 
0124     kvm_set_pfn_accessed(pfn);
0125     if (!orig_pte->may_write || !writable)
0126         rflags |= PP_RXRX;
0127     else {
0128         mark_page_dirty(vcpu->kvm, gfn);
0129         kvm_set_pfn_dirty(pfn);
0130     }
0131 
0132     if (!orig_pte->may_execute)
0133         rflags |= HPTE_R_N;
0134     else
0135         kvmppc_mmu_flush_icache(pfn);
0136 
0137     rflags |= pte_to_hpte_pkey_bits(0, HPTE_USE_KERNEL_KEY);
0138     rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
0139 
0140     /*
0141      * Use 64K pages if possible; otherwise, on 64K page kernels,
0142      * we need to transfer 4 more bits from guest real to host real addr.
0143      */
0144     if (vsid & VSID_64K)
0145         hpsize = MMU_PAGE_64K;
0146     else
0147         hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
0148 
0149     hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
0150 
0151     cpte = kvmppc_mmu_hpte_cache_next(vcpu);
0152 
0153     spin_lock(&kvm->mmu_lock);
0154     if (!cpte || mmu_invalidate_retry(kvm, mmu_seq)) {
0155         r = -EAGAIN;
0156         goto out_unlock;
0157     }
0158 
0159 map_again:
0160     hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
0161 
0162     /* In case we tried normal mapping already, let's nuke old entries */
0163     if (attempt > 1)
0164         if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
0165             r = -1;
0166             goto out_unlock;
0167         }
0168 
0169     ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
0170                        hpsize, hpsize, MMU_SEGSIZE_256M);
0171 
0172     if (ret == -1) {
0173         /* If we couldn't map a primary PTE, try a secondary */
0174         hash = ~hash;
0175         vflags ^= HPTE_V_SECONDARY;
0176         attempt++;
0177         goto map_again;
0178     } else if (ret < 0) {
0179         r = -EIO;
0180         goto out_unlock;
0181     } else {
0182         trace_kvm_book3s_64_mmu_map(rflags, hpteg,
0183                         vpn, hpaddr, orig_pte);
0184 
0185         /*
0186          * The mmu_hash_ops code may give us a secondary entry even
0187          * though we asked for a primary. Fix up.
0188          */
0189         if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
0190             hash = ~hash;
0191             hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
0192         }
0193 
0194         cpte->slot = hpteg + (ret & 7);
0195         cpte->host_vpn = vpn;
0196         cpte->pte = *orig_pte;
0197         cpte->pfn = pfn;
0198         cpte->pagesize = hpsize;
0199 
0200         kvmppc_mmu_hpte_cache_map(vcpu, cpte);
0201         cpte = NULL;
0202     }
0203 
0204 out_unlock:
0205     spin_unlock(&kvm->mmu_lock);
0206     kvm_release_pfn_clean(pfn);
0207     if (cpte)
0208         kvmppc_mmu_hpte_cache_free(cpte);
0209 
0210 out:
0211     return r;
0212 }
0213 
0214 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
0215 {
0216     u64 mask = 0xfffffffffULL;
0217     u64 vsid;
0218 
0219     vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
0220     if (vsid & VSID_64K)
0221         mask = 0xffffffff0ULL;
0222     kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
0223 }
0224 
0225 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
0226 {
0227     unsigned long vsid_bits = VSID_BITS_65_256M;
0228     struct kvmppc_sid_map *map;
0229     struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
0230     u16 sid_map_mask;
0231     static int backwards_map;
0232 
0233     if (kvmppc_get_msr(vcpu) & MSR_PR)
0234         gvsid |= VSID_PR;
0235 
0236     /* We might get collisions that trap in preceding order, so let's
0237        map them differently */
0238 
0239     sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
0240     if (backwards_map)
0241         sid_map_mask = SID_MAP_MASK - sid_map_mask;
0242 
0243     map = &to_book3s(vcpu)->sid_map[sid_map_mask];
0244 
0245     /* Make sure we're taking the other map next time */
0246     backwards_map = !backwards_map;
0247 
0248     /* Uh-oh ... out of mappings. Let's flush! */
0249     if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
0250         vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
0251         memset(vcpu_book3s->sid_map, 0,
0252                sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
0253         kvmppc_mmu_pte_flush(vcpu, 0, 0);
0254         kvmppc_mmu_flush_segments(vcpu);
0255     }
0256 
0257     if (mmu_has_feature(MMU_FTR_68_BIT_VA))
0258         vsid_bits = VSID_BITS_256M;
0259 
0260     map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
0261                        VSID_MULTIPLIER_256M, vsid_bits);
0262 
0263     map->guest_vsid = gvsid;
0264     map->valid = true;
0265 
0266     trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
0267 
0268     return map;
0269 }
0270 
0271 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
0272 {
0273     struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
0274     int i;
0275     int max_slb_size = 64;
0276     int found_inval = -1;
0277     int r;
0278 
0279     /* Are we overwriting? */
0280     for (i = 0; i < svcpu->slb_max; i++) {
0281         if (!(svcpu->slb[i].esid & SLB_ESID_V))
0282             found_inval = i;
0283         else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
0284             r = i;
0285             goto out;
0286         }
0287     }
0288 
0289     /* Found a spare entry that was invalidated before */
0290     if (found_inval >= 0) {
0291         r = found_inval;
0292         goto out;
0293     }
0294 
0295     /* No spare invalid entry, so create one */
0296 
0297     if (mmu_slb_size < 64)
0298         max_slb_size = mmu_slb_size;
0299 
0300     /* Overflowing -> purge */
0301     if ((svcpu->slb_max) == max_slb_size)
0302         kvmppc_mmu_flush_segments(vcpu);
0303 
0304     r = svcpu->slb_max;
0305     svcpu->slb_max++;
0306 
0307 out:
0308     svcpu_put(svcpu);
0309     return r;
0310 }
0311 
0312 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
0313 {
0314     struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
0315     u64 esid = eaddr >> SID_SHIFT;
0316     u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
0317     u64 slb_vsid = SLB_VSID_USER;
0318     u64 gvsid;
0319     int slb_index;
0320     struct kvmppc_sid_map *map;
0321     int r = 0;
0322 
0323     slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
0324 
0325     if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
0326         /* Invalidate an entry */
0327         svcpu->slb[slb_index].esid = 0;
0328         r = -ENOENT;
0329         goto out;
0330     }
0331 
0332     map = find_sid_vsid(vcpu, gvsid);
0333     if (!map)
0334         map = create_sid_map(vcpu, gvsid);
0335 
0336     map->guest_esid = esid;
0337 
0338     slb_vsid |= (map->host_vsid << 12);
0339     slb_vsid &= ~SLB_VSID_KP;
0340     slb_esid |= slb_index;
0341 
0342 #ifdef CONFIG_PPC_64K_PAGES
0343     /* Set host segment base page size to 64K if possible */
0344     if (gvsid & VSID_64K)
0345         slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
0346 #endif
0347 
0348     svcpu->slb[slb_index].esid = slb_esid;
0349     svcpu->slb[slb_index].vsid = slb_vsid;
0350 
0351     trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
0352 
0353 out:
0354     svcpu_put(svcpu);
0355     return r;
0356 }
0357 
0358 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
0359 {
0360     struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
0361     ulong seg_mask = -seg_size;
0362     int i;
0363 
0364     for (i = 0; i < svcpu->slb_max; i++) {
0365         if ((svcpu->slb[i].esid & SLB_ESID_V) &&
0366             (svcpu->slb[i].esid & seg_mask) == ea) {
0367             /* Invalidate this entry */
0368             svcpu->slb[i].esid = 0;
0369         }
0370     }
0371 
0372     svcpu_put(svcpu);
0373 }
0374 
0375 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
0376 {
0377     struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
0378     svcpu->slb_max = 0;
0379     svcpu->slb[0].esid = 0;
0380     svcpu_put(svcpu);
0381 }
0382 
0383 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
0384 {
0385     kvmppc_mmu_hpte_destroy(vcpu);
0386     __destroy_context(to_book3s(vcpu)->context_id[0]);
0387 }
0388 
0389 int kvmppc_mmu_init_pr(struct kvm_vcpu *vcpu)
0390 {
0391     struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
0392     int err;
0393 
0394     err = hash__alloc_context_id();
0395     if (err < 0)
0396         return -1;
0397     vcpu3s->context_id[0] = err;
0398 
0399     vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
0400                   << ESID_BITS) - 1;
0401     vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
0402     vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
0403 
0404     kvmppc_mmu_hpte_init(vcpu);
0405 
0406     return 0;
0407 }
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