/* * guest access functions * * Copyright IBM Corp. 2014 * */ #include #include #include #include "kvm-s390.h" #include "gaccess.h" #include union asce { unsigned long val; struct { unsigned long origin : 52; /* Region- or Segment-Table Origin */ unsigned long : 2; unsigned long g : 1; /* Subspace Group Control */ unsigned long p : 1; /* Private Space Control */ unsigned long s : 1; /* Storage-Alteration-Event Control */ unsigned long x : 1; /* Space-Switch-Event Control */ unsigned long r : 1; /* Real-Space Control */ unsigned long : 1; unsigned long dt : 2; /* Designation-Type Control */ unsigned long tl : 2; /* Region- or Segment-Table Length */ }; }; enum { ASCE_TYPE_SEGMENT = 0, ASCE_TYPE_REGION3 = 1, ASCE_TYPE_REGION2 = 2, ASCE_TYPE_REGION1 = 3 }; union region1_table_entry { unsigned long val; struct { unsigned long rto: 52;/* Region-Table Origin */ unsigned long : 2; unsigned long p : 1; /* DAT-Protection Bit */ unsigned long : 1; unsigned long tf : 2; /* Region-Second-Table Offset */ unsigned long i : 1; /* Region-Invalid Bit */ unsigned long : 1; unsigned long tt : 2; /* Table-Type Bits */ unsigned long tl : 2; /* Region-Second-Table Length */ }; }; union region2_table_entry { unsigned long val; struct { unsigned long rto: 52;/* Region-Table Origin */ unsigned long : 2; unsigned long p : 1; /* DAT-Protection Bit */ unsigned long : 1; unsigned long tf : 2; /* Region-Third-Table Offset */ unsigned long i : 1; /* Region-Invalid Bit */ unsigned long : 1; unsigned long tt : 2; /* Table-Type Bits */ unsigned long tl : 2; /* Region-Third-Table Length */ }; }; struct region3_table_entry_fc0 { unsigned long sto: 52;/* Segment-Table Origin */ unsigned long : 1; unsigned long fc : 1; /* Format-Control */ unsigned long p : 1; /* DAT-Protection Bit */ unsigned long : 1; unsigned long tf : 2; /* Segment-Table Offset */ unsigned long i : 1; /* Region-Invalid Bit */ unsigned long cr : 1; /* Common-Region Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long tl : 2; /* Segment-Table Length */ }; struct region3_table_entry_fc1 { unsigned long rfaa : 33; /* Region-Frame Absolute Address */ unsigned long : 14; unsigned long av : 1; /* ACCF-Validity Control */ unsigned long acc: 4; /* Access-Control Bits */ unsigned long f : 1; /* Fetch-Protection Bit */ unsigned long fc : 1; /* Format-Control */ unsigned long p : 1; /* DAT-Protection Bit */ unsigned long co : 1; /* Change-Recording Override */ unsigned long : 2; unsigned long i : 1; /* Region-Invalid Bit */ unsigned long cr : 1; /* Common-Region Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long : 2; }; union region3_table_entry { unsigned long val; struct region3_table_entry_fc0 fc0; struct region3_table_entry_fc1 fc1; struct { unsigned long : 53; unsigned long fc : 1; /* Format-Control */ unsigned long : 4; unsigned long i : 1; /* Region-Invalid Bit */ unsigned long cr : 1; /* Common-Region Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long : 2; }; }; struct segment_entry_fc0 { unsigned long pto: 53;/* Page-Table Origin */ unsigned long fc : 1; /* Format-Control */ unsigned long p : 1; /* DAT-Protection Bit */ unsigned long : 3; unsigned long i : 1; /* Segment-Invalid Bit */ unsigned long cs : 1; /* Common-Segment Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long : 2; }; struct segment_entry_fc1 { unsigned long sfaa : 44; /* Segment-Frame Absolute Address */ unsigned long : 3; unsigned long av : 1; /* ACCF-Validity Control */ unsigned long acc: 4; /* Access-Control Bits */ unsigned long f : 1; /* Fetch-Protection Bit */ unsigned long fc : 1; /* Format-Control */ unsigned long p : 1; /* DAT-Protection Bit */ unsigned long co : 1; /* Change-Recording Override */ unsigned long : 2; unsigned long i : 1; /* Segment-Invalid Bit */ unsigned long cs : 1; /* Common-Segment Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long : 2; }; union segment_table_entry { unsigned long val; struct segment_entry_fc0 fc0; struct segment_entry_fc1 fc1; struct { unsigned long : 53; unsigned long fc : 1; /* Format-Control */ unsigned long : 4; unsigned long i : 1; /* Segment-Invalid Bit */ unsigned long cs : 1; /* Common-Segment Bit */ unsigned long tt : 2; /* Table-Type Bits */ unsigned long : 2; }; }; enum { TABLE_TYPE_SEGMENT = 0, TABLE_TYPE_REGION3 = 1, TABLE_TYPE_REGION2 = 2, TABLE_TYPE_R
n PGM_REGION_FIRST_TRANS; ptr += vaddr.rfx * 8; break; case ASCE_TYPE_REGION2: if (vaddr.rfx) return PGM_ASCE_TYPE; if (vaddr.rsx01 > asce.tl) return PGM_REGION_SECOND_TRANS; ptr += vaddr.rsx * 8; break; case ASCE_TYPE_REGION3: if (vaddr.rfx || vaddr.rsx) return PGM_ASCE_TYPE; if (vaddr.rtx01 > asce.tl) return PGM_REGION_THIRD_TRANS; ptr += vaddr.rtx * 8; break; case ASCE_TYPE_SEGMENT: if (vaddr.rfx || vaddr.rsx || vaddr.rtx) return PGM_ASCE_TYPE; if (vaddr.sx01 > asce.tl) return PGM_SEGMENT_TRANSLATION; ptr += vaddr.sx * 8; break; } switch (asce.dt) { case ASCE_TYPE_REGION1: { union region1_table_entry rfte; if (kvm_is_error_gpa(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &rfte.val)) return -EFAULT; if (rfte.i) return PGM_REGION_FIRST_TRANS; if (rfte.tt != TABLE_TYPE_REGION1) return PGM_TRANSLATION_SPEC; if (vaddr.rsx01 < rfte.tf || vaddr.rsx01 > rfte.tl) return PGM_REGION_SECOND_TRANS; if (edat1) dat_protection |= rfte.p; ptr = rfte.rto * 4096 + vaddr.rsx * 8; } /* fallthrough */ case ASCE_TYPE_REGION2: { union region2_table_entry rste; if (kvm_is_error_gpa(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &rste.val)) return -EFAULT; if (rste.i) return PGM_REGION_SECOND_TRANS; if (rste.tt != TABLE_TYPE_REGION2) return PGM_TRANSLATION_SPEC; if (vaddr.rtx01 < rste.tf || vaddr.rtx01 > rste.tl) return PGM_REGION_THIRD_TRANS; if (edat1) dat_protection |= rste.p; ptr = rste.rto * 4096 + vaddr.rtx * 8; } /* fallthrough */ case ASCE_TYPE_REGION3: { union region3_table_entry rtte; if (kvm_is_error_gpa(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &rtte.val)) return -EFAULT; if (rtte.i) return PGM_REGION_THIRD_TRANS; if (rtte.tt != TABLE_TYPE_REGION3) return PGM_TRANSLATION_SPEC; if (rtte.cr && asce.p && edat2) return PGM_TRANSLATION_SPEC; if (rtte.fc && edat2) { dat_protection |= rtte.fc1.p; raddr.rfaa = rtte.fc1.rfaa; goto absolute_address; } if (vaddr.sx01 < rtte.fc0.tf) return PGM_SEGMENT_TRANSLATION; if (vaddr.sx01 > rtte.fc0.tl) return PGM_SEGMENT_TRANSLATION; if (edat1) dat_protection |= rtte.fc0.p; ptr = rtte.fc0.sto * 4096 + vaddr.sx * 8; } /* fallthrough */ case ASCE_TYPE_SEGMENT: { union segment_table_entry ste; if (kvm_is_error_gpa(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &ste.val)) return -EFAULT; if (ste.i) return PGM_SEGMENT_TRANSLATION; if (ste.tt != TABLE_TYPE_SEGMENT) return PGM_TRANSLATION_SPEC; if (ste.cs && asce.p) return PGM_TRANSLATION_SPEC; if (ste.fc && edat1) { dat_protection |= ste.fc1.p; raddr.sfaa = ste.fc1.sfaa; goto absolute_address; } dat_protection |= ste.fc0.p; ptr = ste.fc0.pto * 2048 + vaddr.px * 8; } } if (kvm_is_error_gpa(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &pte.val)) return -EFAULT; if (pte.i) return PGM_PAGE_TRANSLATION; if (pte.z) return PGM_TRANSLATION_SPEC; if (pte.co && !edat1) return PGM_TRANSLATION_SPEC; dat_protection |= pte.p; raddr.pfra = pte.pfra; real_address: raddr.addr = kvm_s390_real_to_abs(vcpu, raddr.addr); absolute_address: if (write && dat_protection) return PGM_PROTECTION; if (kvm_is_error_gpa(vcpu->kvm, raddr.addr)) return PGM_ADDRESSING; *gpa = raddr.addr; return 0; } static inline int is_low_address(unsigned long ga) { /* Check for address ranges 0..511 and 4096..4607 */ return (ga & ~0x11fful) == 0; } static int low_address_protection_enabled(struct kvm_vcpu *vcpu, const union asce asce) { union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]}; psw_t *psw = &vcpu->arch.sie_block->gpsw; if (!ctlreg0.lap) return 0; if (psw_bits(*psw).t && asce.p) return 0; return 1; } static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, unsigned long *pages, unsigned long nr_pages, const union asce asce, int write) { struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; psw_t *psw = &vcpu->arch.sie_block->gpsw; struct trans_exc_code_bits *tec_bits; int lap_enabled, rc; tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code; lap_enabled = low_address_protection_enabled(vcpu, asce); while (nr_pages) { ga = kvm_s390_logical_to_effective(vcpu, ga); tec_bits->addr = ga >> PAGE_SHIFT; if (write && lap_enabled && is_low_address(ga)) { pgm->code = PGM_PROTECTION; return pgm->code; } ga &= PAGE_MASK; if (psw_bits(*psw).t) { rc = guest_translate(vcpu, ga, pages, asce, write); if (rc < 0) return rc; if (rc == PGM_PROTECTION) tec_bits->b61 = 1; if (rc) pgm->code = rc; } else { *pages = kvm_s390_real_to_abs(vcpu, ga); if (kvm_is_error_gpa(vcpu->kvm, *pages)) pgm->code = PGM_ADDRESSING; } if (pgm->code) return pgm->code; ga += PAGE_SIZE; pages++; nr_pages--; } return 0; } int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data, unsigned long len, int write) { psw_t *psw = &vcpu->arch.sie_block->gpsw; unsigned long _len, nr_pages, gpa, idx; unsigned long pages_array[2]; unsigned long *pages; int need_ipte_lock; union asce asce; int rc; if (!len) return 0; rc = get_vcpu_asce(vcpu, &asce, ar, write); if (rc) return rc; nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1; pages = pages_array; if (nr_pages > ARRAY_SIZE(pages_array)) pages = vmalloc(nr_pages * sizeof(unsigned long)); if (!pages) return -ENOMEM; need_ipte_lock = psw_bits(*psw).t && !asce.r; if (need_ipte_lock) ipte_lock(vcpu); rc = guest_page_range(vcpu, ga, pages, nr_pages, asce, write); for (idx = 0; idx < nr_pages && !rc; idx++) { gpa = *(pages + idx) + (ga & ~PAGE_MASK); _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); if (write) rc = kvm_write_guest(vcpu->kvm, gpa, data, _len); else rc = kvm_read_guest(vcpu->kvm, gpa, data, _len); len -= _len; ga += _len; data += _len; } if (need_ipte_lock) ipte_unlock(vcpu); if (nr_pages > ARRAY_SIZE(pages_array)) vfree(pages); return rc; } int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, unsigned long len, int write) { unsigned long _len, gpa; int rc = 0; while (len && !rc) { gpa = kvm_s390_real_to_abs(vcpu, gra); _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); if (write) rc = write_guest_abs(vcpu, gpa, data, _len); else rc = read_guest_abs(vcpu, gpa, data, _len); len -= _len; gra += _len; data += _len; } return rc; } /** * guest_translate_address - translate guest logical into guest absolute address * * Parameter semantics are the same as the ones from guest_translate. * The memory contents at the guest address are not changed. * * Note: The IPTE lock is not taken during this function, so the caller * has to take care of this. */ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar, unsigned long *gpa, int write) { struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; psw_t *psw = &vcpu->arch.sie_block->gpsw; struct trans_exc_code_bits *tec; union asce asce; int rc; gva = kvm_s390_logical_to_effective(vcpu, gva); tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code; rc = get_vcpu_asce(vcpu, &asce, ar, write); tec->addr = gva >> PAGE_SHIFT; if (rc) return rc; if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) { if (write) { rc = pgm->code = PGM_PROTECTION; return rc; } } if (psw_bits(*psw).t && !asce.r) { /* Use DAT? */ rc = guest_translate(vcpu, gva, gpa, asce, write); if (rc > 0) { if (rc == PGM_PROTECTION) tec->b61 = 1; pgm->code = rc; } } else { rc = 0; *gpa = kvm_s390_real_to_abs(vcpu, gva); if (kvm_is_error_gpa(vcpu->kvm, *gpa)) rc = pgm->code = PGM_ADDRESSING; } return rc; } /** * check_gva_range - test a range of guest virtual addresses for accessibility */ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar, unsigned long length, int is_write) { unsigned long gpa; unsigned long currlen; int rc = 0; ipte_lock(vcpu); while (length > 0 && !rc) { currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE)); rc = guest_translate_address(vcpu, gva, ar, &gpa, is_write); gva += currlen; length -= currlen; } ipte_unlock(vcpu); return rc; } /** * kvm_s390_check_low_addr_prot_real - check for low-address protection * @gra: Guest real address * * Checks whether an address is subject to low-address protection and set * up vcpu->arch.pgm accordingly if necessary. * * Return: 0 if no protection exception, or PGM_PROTECTION if protected. */ int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra) { struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; psw_t *psw = &vcpu->arch.sie_block->gpsw; struct trans_exc_code_bits *tec_bits; union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]}; if (!ctlreg0.lap || !is_low_address(gra)) return 0; memset(pgm, 0, sizeof(*pgm)); tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code; tec_bits->fsi = FSI_STORE; tec_bits->as = psw_bits(*psw).as; tec_bits->addr = gra >> PAGE_SHIFT; pgm->code = PGM_PROTECTION; return pgm->code; }