diff options
Diffstat (limited to 'arch/s390/kvm/gaccess.c')
| -rw-r--r-- | arch/s390/kvm/gaccess.c | 1227 |
1 files changed, 1227 insertions, 0 deletions
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c new file mode 100644 index 000000000..b9f85b2dc --- /dev/null +++ b/arch/s390/kvm/gaccess.c @@ -0,0 +1,1227 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * guest access functions + * + * Copyright IBM Corp. 2014 + * + */ + +#include <linux/vmalloc.h> +#include <linux/mm_types.h> +#include <linux/err.h> +#include <linux/pgtable.h> + +#include <asm/gmap.h> +#include "kvm-s390.h" +#include "gaccess.h" +#include <asm/switch_to.h> + +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 iep: 1; /* Instruction-Execution-Protection */ + 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 iep: 1; /* Instruction-Execution-Protection */ + 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_REGION1 = 3 +}; + +union page_table_entry { + unsigned long val; + struct { + unsigned long pfra : 52; /* Page-Frame Real Address */ + unsigned long z : 1; /* Zero Bit */ + unsigned long i : 1; /* Page-Invalid Bit */ + unsigned long p : 1; /* DAT-Protection Bit */ + unsigned long iep: 1; /* Instruction-Execution-Protection */ + unsigned long : 8; + }; +}; + +/* + * vaddress union in order to easily decode a virtual address into its + * region first index, region second index etc. parts. + */ +union vaddress { + unsigned long addr; + struct { + unsigned long rfx : 11; + unsigned long rsx : 11; + unsigned long rtx : 11; + unsigned long sx : 11; + unsigned long px : 8; + unsigned long bx : 12; + }; + struct { + unsigned long rfx01 : 2; + unsigned long : 9; + unsigned long rsx01 : 2; + unsigned long : 9; + unsigned long rtx01 : 2; + unsigned long : 9; + unsigned long sx01 : 2; + unsigned long : 29; + }; +}; + +/* + * raddress union which will contain the result (real or absolute address) + * after a page table walk. The rfaa, sfaa and pfra members are used to + * simply assign them the value of a region, segment or page table entry. + */ +union raddress { + unsigned long addr; + unsigned long rfaa : 33; /* Region-Frame Absolute Address */ + unsigned long sfaa : 44; /* Segment-Frame Absolute Address */ + unsigned long pfra : 52; /* Page-Frame Real Address */ +}; + +union alet { + u32 val; + struct { + u32 reserved : 7; + u32 p : 1; + u32 alesn : 8; + u32 alen : 16; + }; +}; + +union ald { + u32 val; + struct { + u32 : 1; + u32 alo : 24; + u32 all : 7; + }; +}; + +struct ale { + unsigned long i : 1; /* ALEN-Invalid Bit */ + unsigned long : 5; + unsigned long fo : 1; /* Fetch-Only Bit */ + unsigned long p : 1; /* Private Bit */ + unsigned long alesn : 8; /* Access-List-Entry Sequence Number */ + unsigned long aleax : 16; /* Access-List-Entry Authorization Index */ + unsigned long : 32; + unsigned long : 1; + unsigned long asteo : 25; /* ASN-Second-Table-Entry Origin */ + unsigned long : 6; + unsigned long astesn : 32; /* ASTE Sequence Number */ +}; + +struct aste { + unsigned long i : 1; /* ASX-Invalid Bit */ + unsigned long ato : 29; /* Authority-Table Origin */ + unsigned long : 1; + unsigned long b : 1; /* Base-Space Bit */ + unsigned long ax : 16; /* Authorization Index */ + unsigned long atl : 12; /* Authority-Table Length */ + unsigned long : 2; + unsigned long ca : 1; /* Controlled-ASN Bit */ + unsigned long ra : 1; /* Reusable-ASN Bit */ + unsigned long asce : 64; /* Address-Space-Control Element */ + unsigned long ald : 32; + unsigned long astesn : 32; + /* .. more fields there */ +}; + +int ipte_lock_held(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.sie_block->eca & ECA_SII) { + int rc; + + read_lock(&vcpu->kvm->arch.sca_lock); + rc = kvm_s390_get_ipte_control(vcpu->kvm)->kh != 0; + read_unlock(&vcpu->kvm->arch.sca_lock); + return rc; + } + return vcpu->kvm->arch.ipte_lock_count != 0; +} + +static void ipte_lock_simple(struct kvm_vcpu *vcpu) +{ + union ipte_control old, new, *ic; + + mutex_lock(&vcpu->kvm->arch.ipte_mutex); + vcpu->kvm->arch.ipte_lock_count++; + if (vcpu->kvm->arch.ipte_lock_count > 1) + goto out; +retry: + read_lock(&vcpu->kvm->arch.sca_lock); + ic = kvm_s390_get_ipte_control(vcpu->kvm); + do { + old = READ_ONCE(*ic); + if (old.k) { + read_unlock(&vcpu->kvm->arch.sca_lock); + cond_resched(); + goto retry; + } + new = old; + new.k = 1; + } while (cmpxchg(&ic->val, old.val, new.val) != old.val); + read_unlock(&vcpu->kvm->arch.sca_lock); +out: + mutex_unlock(&vcpu->kvm->arch.ipte_mutex); +} + +static void ipte_unlock_simple(struct kvm_vcpu *vcpu) +{ + union ipte_control old, new, *ic; + + mutex_lock(&vcpu->kvm->arch.ipte_mutex); + vcpu->kvm->arch.ipte_lock_count--; + if (vcpu->kvm->arch.ipte_lock_count) + goto out; + read_lock(&vcpu->kvm->arch.sca_lock); + ic = kvm_s390_get_ipte_control(vcpu->kvm); + do { + old = READ_ONCE(*ic); + new = old; + new.k = 0; + } while (cmpxchg(&ic->val, old.val, new.val) != old.val); + read_unlock(&vcpu->kvm->arch.sca_lock); + wake_up(&vcpu->kvm->arch.ipte_wq); +out: + mutex_unlock(&vcpu->kvm->arch.ipte_mutex); +} + +static void ipte_lock_siif(struct kvm_vcpu *vcpu) +{ + union ipte_control old, new, *ic; + +retry: + read_lock(&vcpu->kvm->arch.sca_lock); + ic = kvm_s390_get_ipte_control(vcpu->kvm); + do { + old = READ_ONCE(*ic); + if (old.kg) { + read_unlock(&vcpu->kvm->arch.sca_lock); + cond_resched(); + goto retry; + } + new = old; + new.k = 1; + new.kh++; + } while (cmpxchg(&ic->val, old.val, new.val) != old.val); + read_unlock(&vcpu->kvm->arch.sca_lock); +} + +static void ipte_unlock_siif(struct kvm_vcpu *vcpu) +{ + union ipte_control old, new, *ic; + + read_lock(&vcpu->kvm->arch.sca_lock); + ic = kvm_s390_get_ipte_control(vcpu->kvm); + do { + old = READ_ONCE(*ic); + new = old; + new.kh--; + if (!new.kh) + new.k = 0; + } while (cmpxchg(&ic->val, old.val, new.val) != old.val); + read_unlock(&vcpu->kvm->arch.sca_lock); + if (!new.kh) + wake_up(&vcpu->kvm->arch.ipte_wq); +} + +void ipte_lock(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.sie_block->eca & ECA_SII) + ipte_lock_siif(vcpu); + else + ipte_lock_simple(vcpu); +} + +void ipte_unlock(struct kvm_vcpu *vcpu) +{ + if (vcpu->arch.sie_block->eca & ECA_SII) + ipte_unlock_siif(vcpu); + else + ipte_unlock_simple(vcpu); +} + +static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, u8 ar, + enum gacc_mode mode) +{ + union alet alet; + struct ale ale; + struct aste aste; + unsigned long ald_addr, authority_table_addr; + union ald ald; + int eax, rc; + u8 authority_table; + + if (ar >= NUM_ACRS) + return -EINVAL; + + save_access_regs(vcpu->run->s.regs.acrs); + alet.val = vcpu->run->s.regs.acrs[ar]; + + if (ar == 0 || alet.val == 0) { + asce->val = vcpu->arch.sie_block->gcr[1]; + return 0; + } else if (alet.val == 1) { + asce->val = vcpu->arch.sie_block->gcr[7]; + return 0; + } + + if (alet.reserved) + return PGM_ALET_SPECIFICATION; + + if (alet.p) + ald_addr = vcpu->arch.sie_block->gcr[5]; + else + ald_addr = vcpu->arch.sie_block->gcr[2]; + ald_addr &= 0x7fffffc0; + + rc = read_guest_real(vcpu, ald_addr + 16, &ald.val, sizeof(union ald)); + if (rc) + return rc; + + if (alet.alen / 8 > ald.all) + return PGM_ALEN_TRANSLATION; + + if (0x7fffffff - ald.alo * 128 < alet.alen * 16) + return PGM_ADDRESSING; + + rc = read_guest_real(vcpu, ald.alo * 128 + alet.alen * 16, &ale, + sizeof(struct ale)); + if (rc) + return rc; + + if (ale.i == 1) + return PGM_ALEN_TRANSLATION; + if (ale.alesn != alet.alesn) + return PGM_ALE_SEQUENCE; + + rc = read_guest_real(vcpu, ale.asteo * 64, &aste, sizeof(struct aste)); + if (rc) + return rc; + + if (aste.i) + return PGM_ASTE_VALIDITY; + if (aste.astesn != ale.astesn) + return PGM_ASTE_SEQUENCE; + + if (ale.p == 1) { + eax = (vcpu->arch.sie_block->gcr[8] >> 16) & 0xffff; + if (ale.aleax != eax) { + if (eax / 16 > aste.atl) + return PGM_EXTENDED_AUTHORITY; + + authority_table_addr = aste.ato * 4 + eax / 4; + + rc = read_guest_real(vcpu, authority_table_addr, + &authority_table, + sizeof(u8)); + if (rc) + return rc; + + if ((authority_table & (0x40 >> ((eax & 3) * 2))) == 0) + return PGM_EXTENDED_AUTHORITY; + } + } + + if (ale.fo == 1 && mode == GACC_STORE) + return PGM_PROTECTION; + + asce->val = aste.asce; + return 0; +} + +struct trans_exc_code_bits { + unsigned long addr : 52; /* Translation-exception Address */ + unsigned long fsi : 2; /* Access Exception Fetch/Store Indication */ + unsigned long : 2; + unsigned long b56 : 1; + unsigned long : 3; + unsigned long b60 : 1; + unsigned long b61 : 1; + unsigned long as : 2; /* ASCE Identifier */ +}; + +enum { + FSI_UNKNOWN = 0, /* Unknown wether fetch or store */ + FSI_STORE = 1, /* Exception was due to store operation */ + FSI_FETCH = 2 /* Exception was due to fetch operation */ +}; + +enum prot_type { + PROT_TYPE_LA = 0, + PROT_TYPE_KEYC = 1, + PROT_TYPE_ALC = 2, + PROT_TYPE_DAT = 3, + PROT_TYPE_IEP = 4, +}; + +static int trans_exc(struct kvm_vcpu *vcpu, int code, unsigned long gva, + u8 ar, enum gacc_mode mode, enum prot_type prot) +{ + struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm; + struct trans_exc_code_bits *tec; + + memset(pgm, 0, sizeof(*pgm)); + pgm->code = code; + tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code; + + switch (code) { + case PGM_PROTECTION: + switch (prot) { + case PROT_TYPE_IEP: + tec->b61 = 1; + fallthrough; + case PROT_TYPE_LA: + tec->b56 = 1; + break; + case PROT_TYPE_KEYC: + tec->b60 = 1; + break; + case PROT_TYPE_ALC: + tec->b60 = 1; + fallthrough; + case PROT_TYPE_DAT: + tec->b61 = 1; + break; + } + fallthrough; + case PGM_ASCE_TYPE: + case PGM_PAGE_TRANSLATION: + case PGM_REGION_FIRST_TRANS: + case PGM_REGION_SECOND_TRANS: + case PGM_REGION_THIRD_TRANS: + case PGM_SEGMENT_TRANSLATION: + /* + * op_access_id only applies to MOVE_PAGE -> set bit 61 + * exc_access_id has to be set to 0 for some instructions. Both + * cases have to be handled by the caller. + */ + tec->addr = gva >> PAGE_SHIFT; + tec->fsi = mode == GACC_STORE ? FSI_STORE : FSI_FETCH; + tec->as = psw_bits(vcpu->arch.sie_block->gpsw).as; + fallthrough; + case PGM_ALEN_TRANSLATION: + case PGM_ALE_SEQUENCE: + case PGM_ASTE_VALIDITY: + case PGM_ASTE_SEQUENCE: + case PGM_EXTENDED_AUTHORITY: + /* + * We can always store exc_access_id, as it is + * undefined for non-ar cases. It is undefined for + * most DAT protection exceptions. + */ + pgm->exc_access_id = ar; + break; + } + return code; +} + +static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce, + unsigned long ga, u8 ar, enum gacc_mode mode) +{ + int rc; + struct psw_bits psw = psw_bits(vcpu->arch.sie_block->gpsw); + + if (!psw.dat) { + asce->val = 0; + asce->r = 1; + return 0; + } + + if ((mode == GACC_IFETCH) && (psw.as != PSW_BITS_AS_HOME)) + psw.as = PSW_BITS_AS_PRIMARY; + + switch (psw.as) { + case PSW_BITS_AS_PRIMARY: + asce->val = vcpu->arch.sie_block->gcr[1]; + return 0; + case PSW_BITS_AS_SECONDARY: + asce->val = vcpu->arch.sie_block->gcr[7]; + return 0; + case PSW_BITS_AS_HOME: + asce->val = vcpu->arch.sie_block->gcr[13]; + return 0; + case PSW_BITS_AS_ACCREG: + rc = ar_translation(vcpu, asce, ar, mode); + if (rc > 0) + return trans_exc(vcpu, rc, ga, ar, mode, PROT_TYPE_ALC); + return rc; + } + return 0; +} + +static int deref_table(struct kvm *kvm, unsigned long gpa, unsigned long *val) +{ + return kvm_read_guest(kvm, gpa, val, sizeof(*val)); +} + +/** + * guest_translate - translate a guest virtual into a guest absolute address + * @vcpu: virtual cpu + * @gva: guest virtual address + * @gpa: points to where guest physical (absolute) address should be stored + * @asce: effective asce + * @mode: indicates the access mode to be used + * @prot: returns the type for protection exceptions + * + * Translate a guest virtual address into a guest absolute address by means + * of dynamic address translation as specified by the architecture. + * If the resulting absolute address is not available in the configuration + * an addressing exception is indicated and @gpa will not be changed. + * + * Returns: - zero on success; @gpa contains the resulting absolute address + * - a negative value if guest access failed due to e.g. broken + * guest mapping + * - a positve value if an access exception happened. In this case + * the returned value is the program interruption code as defined + * by the architecture + */ +static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, + unsigned long *gpa, const union asce asce, + enum gacc_mode mode, enum prot_type *prot) +{ + union vaddress vaddr = {.addr = gva}; + union raddress raddr = {.addr = gva}; + union page_table_entry pte; + int dat_protection = 0; + int iep_protection = 0; + union ctlreg0 ctlreg0; + unsigned long ptr; + int edat1, edat2, iep; + + ctlreg0.val = vcpu->arch.sie_block->gcr[0]; + edat1 = ctlreg0.edat && test_kvm_facility(vcpu->kvm, 8); + edat2 = edat1 && test_kvm_facility(vcpu->kvm, 78); + iep = ctlreg0.iep && test_kvm_facility(vcpu->kvm, 130); + if (asce.r) + goto real_address; + ptr = asce.origin * PAGE_SIZE; + switch (asce.dt) { + case ASCE_TYPE_REGION1: + if (vaddr.rfx01 > asce.tl) + return 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 * PAGE_SIZE + 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 * PAGE_SIZE + 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; + iep_protection = rtte.fc1.iep; + 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 * PAGE_SIZE + 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; + iep_protection = ste.fc1.iep; + raddr.sfaa = ste.fc1.sfaa; + goto absolute_address; + } + dat_protection |= ste.fc0.p; + ptr = ste.fc0.pto * (PAGE_SIZE / 2) + 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; + dat_protection |= pte.p; + iep_protection = pte.iep; + raddr.pfra = pte.pfra; +real_address: + raddr.addr = kvm_s390_real_to_abs(vcpu, raddr.addr); +absolute_address: + if (mode == GACC_STORE && dat_protection) { + *prot = PROT_TYPE_DAT; + return PGM_PROTECTION; + } + if (mode == GACC_IFETCH && iep_protection && iep) { + *prot = PROT_TYPE_IEP; + 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).dat && asce.p) + return 0; + return 1; +} + +static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, + unsigned long *pages, unsigned long nr_pages, + const union asce asce, enum gacc_mode mode) +{ + psw_t *psw = &vcpu->arch.sie_block->gpsw; + int lap_enabled, rc = 0; + enum prot_type prot; + + lap_enabled = low_address_protection_enabled(vcpu, asce); + while (nr_pages) { + ga = kvm_s390_logical_to_effective(vcpu, ga); + if (mode == GACC_STORE && lap_enabled && is_low_address(ga)) + return trans_exc(vcpu, PGM_PROTECTION, ga, ar, mode, + PROT_TYPE_LA); + ga &= PAGE_MASK; + if (psw_bits(*psw).dat) { + rc = guest_translate(vcpu, ga, pages, asce, mode, &prot); + if (rc < 0) + return rc; + } else { + *pages = kvm_s390_real_to_abs(vcpu, ga); + if (kvm_is_error_gpa(vcpu->kvm, *pages)) + rc = PGM_ADDRESSING; + } + if (rc) + return trans_exc(vcpu, rc, ga, ar, mode, prot); + ga += PAGE_SIZE; + pages++; + nr_pages--; + } + return 0; +} + +int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, + unsigned long len, enum gacc_mode mode) +{ + 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; + ga = kvm_s390_logical_to_effective(vcpu, ga); + rc = get_vcpu_asce(vcpu, &asce, ga, ar, mode); + 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(array_size(nr_pages, sizeof(unsigned long))); + if (!pages) + return -ENOMEM; + need_ipte_lock = psw_bits(*psw).dat && !asce.r; + if (need_ipte_lock) + ipte_lock(vcpu); + rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode); + for (idx = 0; idx < nr_pages && !rc; idx++) { + gpa = *(pages + idx) + (ga & ~PAGE_MASK); + _len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); + if (mode == GACC_STORE) + 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, enum gacc_mode mode) +{ + 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 (mode) + 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, u8 ar, + unsigned long *gpa, enum gacc_mode mode) +{ + psw_t *psw = &vcpu->arch.sie_block->gpsw; + enum prot_type prot; + union asce asce; + int rc; + + gva = kvm_s390_logical_to_effective(vcpu, gva); + rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode); + if (rc) + return rc; + if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) { + if (mode == GACC_STORE) + return trans_exc(vcpu, PGM_PROTECTION, gva, 0, + mode, PROT_TYPE_LA); + } + + if (psw_bits(*psw).dat && !asce.r) { /* Use DAT? */ + rc = guest_translate(vcpu, gva, gpa, asce, mode, &prot); + if (rc > 0) + return trans_exc(vcpu, rc, gva, 0, mode, prot); + } else { + *gpa = kvm_s390_real_to_abs(vcpu, gva); + if (kvm_is_error_gpa(vcpu->kvm, *gpa)) + return trans_exc(vcpu, rc, gva, PGM_ADDRESSING, mode, 0); + } + + 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, u8 ar, + unsigned long length, enum gacc_mode mode) +{ + 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, mode); + 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) +{ + union ctlreg0 ctlreg0 = {.val = vcpu->arch.sie_block->gcr[0]}; + + if (!ctlreg0.lap || !is_low_address(gra)) + return 0; + return trans_exc(vcpu, PGM_PROTECTION, gra, 0, GACC_STORE, PROT_TYPE_LA); +} + +/** + * kvm_s390_shadow_tables - walk the guest page table and create shadow tables + * @sg: pointer to the shadow guest address space structure + * @saddr: faulting address in the shadow gmap + * @pgt: pointer to the beginning of the page table for the given address if + * successful (return value 0), or to the first invalid DAT entry in + * case of exceptions (return value > 0) + * @fake: pgt references contiguous guest memory block, not a pgtable + */ +static int kvm_s390_shadow_tables(struct gmap *sg, unsigned long saddr, + unsigned long *pgt, int *dat_protection, + int *fake) +{ + struct gmap *parent; + union asce asce; + union vaddress vaddr; + unsigned long ptr; + int rc; + + *fake = 0; + *dat_protection = 0; + parent = sg->parent; + vaddr.addr = saddr; + asce.val = sg->orig_asce; + ptr = asce.origin * PAGE_SIZE; + if (asce.r) { + *fake = 1; + ptr = 0; + asce.dt = ASCE_TYPE_REGION1; + } + switch (asce.dt) { + case ASCE_TYPE_REGION1: + if (vaddr.rfx01 > asce.tl && !*fake) + return PGM_REGION_FIRST_TRANS; + break; + case ASCE_TYPE_REGION2: + if (vaddr.rfx) + return PGM_ASCE_TYPE; + if (vaddr.rsx01 > asce.tl) + return PGM_REGION_SECOND_TRANS; + break; + case ASCE_TYPE_REGION3: + if (vaddr.rfx || vaddr.rsx) + return PGM_ASCE_TYPE; + if (vaddr.rtx01 > asce.tl) + return PGM_REGION_THIRD_TRANS; + 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; + break; + } + + switch (asce.dt) { + case ASCE_TYPE_REGION1: { + union region1_table_entry rfte; + + if (*fake) { + ptr += vaddr.rfx * _REGION1_SIZE; + rfte.val = ptr; + goto shadow_r2t; + } + *pgt = ptr + vaddr.rfx * 8; + rc = gmap_read_table(parent, ptr + vaddr.rfx * 8, &rfte.val); + if (rc) + return rc; + 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 (sg->edat_level >= 1) + *dat_protection |= rfte.p; + ptr = rfte.rto * PAGE_SIZE; +shadow_r2t: + rc = gmap_shadow_r2t(sg, saddr, rfte.val, *fake); + if (rc) + return rc; + } + fallthrough; + case ASCE_TYPE_REGION2: { + union region2_table_entry rste; + + if (*fake) { + ptr += vaddr.rsx * _REGION2_SIZE; + rste.val = ptr; + goto shadow_r3t; + } + *pgt = ptr + vaddr.rsx * 8; + rc = gmap_read_table(parent, ptr + vaddr.rsx * 8, &rste.val); + if (rc) + return rc; + 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 (sg->edat_level >= 1) + *dat_protection |= rste.p; + ptr = rste.rto * PAGE_SIZE; +shadow_r3t: + rste.p |= *dat_protection; + rc = gmap_shadow_r3t(sg, saddr, rste.val, *fake); + if (rc) + return rc; + } + fallthrough; + case ASCE_TYPE_REGION3: { + union region3_table_entry rtte; + + if (*fake) { + ptr += vaddr.rtx * _REGION3_SIZE; + rtte.val = ptr; + goto shadow_sgt; + } + *pgt = ptr + vaddr.rtx * 8; + rc = gmap_read_table(parent, ptr + vaddr.rtx * 8, &rtte.val); + if (rc) + return rc; + if (rtte.i) + return PGM_REGION_THIRD_TRANS; + if (rtte.tt != TABLE_TYPE_REGION3) + return PGM_TRANSLATION_SPEC; + if (rtte.cr && asce.p && sg->edat_level >= 2) + return PGM_TRANSLATION_SPEC; + if (rtte.fc && sg->edat_level >= 2) { + *dat_protection |= rtte.fc0.p; + *fake = 1; + ptr = rtte.fc1.rfaa * _REGION3_SIZE; + rtte.val = ptr; + goto shadow_sgt; + } + if (vaddr.sx01 < rtte.fc0.tf || vaddr.sx01 > rtte.fc0.tl) + return PGM_SEGMENT_TRANSLATION; + if (sg->edat_level >= 1) + *dat_protection |= rtte.fc0.p; + ptr = rtte.fc0.sto * PAGE_SIZE; +shadow_sgt: + rtte.fc0.p |= *dat_protection; + rc = gmap_shadow_sgt(sg, saddr, rtte.val, *fake); + if (rc) + return rc; + } + fallthrough; + case ASCE_TYPE_SEGMENT: { + union segment_table_entry ste; + + if (*fake) { + ptr += vaddr.sx * _SEGMENT_SIZE; + ste.val = ptr; + goto shadow_pgt; + } + *pgt = ptr + vaddr.sx * 8; + rc = gmap_read_table(parent, ptr + vaddr.sx * 8, &ste.val); + if (rc) + return rc; + 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; + *dat_protection |= ste.fc0.p; + if (ste.fc && sg->edat_level >= 1) { + *fake = 1; + ptr = ste.fc1.sfaa * _SEGMENT_SIZE; + ste.val = ptr; + goto shadow_pgt; + } + ptr = ste.fc0.pto * (PAGE_SIZE / 2); +shadow_pgt: + ste.fc0.p |= *dat_protection; + rc = gmap_shadow_pgt(sg, saddr, ste.val, *fake); + if (rc) + return rc; + } + } + /* Return the parent address of the page table */ + *pgt = ptr; + return 0; +} + +/** + * kvm_s390_shadow_fault - handle fault on a shadow page table + * @vcpu: virtual cpu + * @sg: pointer to the shadow guest address space structure + * @saddr: faulting address in the shadow gmap + * @datptr: will contain the address of the faulting DAT table entry, or of + * the valid leaf, plus some flags + * + * Returns: - 0 if the shadow fault was successfully resolved + * - > 0 (pgm exception code) on exceptions while faulting + * - -EAGAIN if the caller can retry immediately + * - -EFAULT when accessing invalid guest addresses + * - -ENOMEM if out of memory + */ +int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg, + unsigned long saddr, unsigned long *datptr) +{ + union vaddress vaddr; + union page_table_entry pte; + unsigned long pgt = 0; + int dat_protection, fake; + int rc; + + mmap_read_lock(sg->mm); + /* + * We don't want any guest-2 tables to change - so the parent + * tables/pointers we read stay valid - unshadowing is however + * always possible - only guest_table_lock protects us. + */ + ipte_lock(vcpu); + + rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection, &fake); + if (rc) + rc = kvm_s390_shadow_tables(sg, saddr, &pgt, &dat_protection, + &fake); + + vaddr.addr = saddr; + if (fake) { + pte.val = pgt + vaddr.px * PAGE_SIZE; + goto shadow_page; + } + + switch (rc) { + case PGM_SEGMENT_TRANSLATION: + case PGM_REGION_THIRD_TRANS: + case PGM_REGION_SECOND_TRANS: + case PGM_REGION_FIRST_TRANS: + pgt |= PEI_NOT_PTE; + break; + case 0: + pgt += vaddr.px * 8; + rc = gmap_read_table(sg->parent, pgt, &pte.val); + } + if (datptr) + *datptr = pgt | dat_protection * PEI_DAT_PROT; + if (!rc && pte.i) + rc = PGM_PAGE_TRANSLATION; + if (!rc && pte.z) + rc = PGM_TRANSLATION_SPEC; +shadow_page: + pte.p |= dat_protection; + if (!rc) + rc = gmap_shadow_page(sg, saddr, __pte(pte.val)); + ipte_unlock(vcpu); + mmap_read_unlock(sg->mm); + return rc; +} |