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-rw-r--r--kernel/arch/s390/kvm/gaccess.c915
1 files changed, 915 insertions, 0 deletions
diff --git a/kernel/arch/s390/kvm/gaccess.c b/kernel/arch/s390/kvm/gaccess.c
new file mode 100644
index 000000000..a7559f720
--- /dev/null
+++ b/kernel/arch/s390/kvm/gaccess.c
@@ -0,0 +1,915 @@
+/*
+ * guest access functions
+ *
+ * Copyright IBM Corp. 2014
+ *
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/err.h>
+#include <asm/pgtable.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 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_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 co : 1; /* Change-Recording Override */
+ 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 */
+} __packed;
+
+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 */
+} __packed;
+
+int ipte_lock_held(struct kvm_vcpu *vcpu)
+{
+ union ipte_control *ic = &vcpu->kvm->arch.sca->ipte_control;
+
+ if (vcpu->arch.sie_block->eca & 1)
+ return ic->kh != 0;
+ 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;
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ old = READ_ONCE(*ic);
+ while (old.k) {
+ cond_resched();
+ old = READ_ONCE(*ic);
+ }
+ new = old;
+ new.k = 1;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+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;
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ old = READ_ONCE(*ic);
+ new = old;
+ new.k = 0;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+ 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;
+
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ do {
+ old = READ_ONCE(*ic);
+ while (old.kg) {
+ cond_resched();
+ old = READ_ONCE(*ic);
+ }
+ new = old;
+ new.k = 1;
+ new.kh++;
+ } while (cmpxchg(&ic->val, old.val, new.val) != old.val);
+}
+
+static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
+{
+ union ipte_control old, new, *ic;
+
+ ic = &vcpu->kvm->arch.sca->ipte_control;
+ 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);
+ if (!new.kh)
+ wake_up(&vcpu->kvm->arch.ipte_wq);
+}
+
+void ipte_lock(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.sie_block->eca & 1)
+ ipte_lock_siif(vcpu);
+ else
+ ipte_lock_simple(vcpu);
+}
+
+void ipte_unlock(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.sie_block->eca & 1)
+ ipte_unlock_siif(vcpu);
+ else
+ ipte_unlock_simple(vcpu);
+}
+
+static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce, ar_t ar,
+ int write)
+{
+ 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 && write)
+ 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 : 6;
+ 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 */
+};
+
+static int get_vcpu_asce(struct kvm_vcpu *vcpu, union asce *asce,
+ ar_t ar, int write)
+{
+ int rc;
+ psw_t *psw = &vcpu->arch.sie_block->gpsw;
+ struct kvm_s390_pgm_info *pgm = &vcpu->arch.pgm;
+ struct trans_exc_code_bits *tec_bits;
+
+ memset(pgm, 0, sizeof(*pgm));
+ tec_bits = (struct trans_exc_code_bits *)&pgm->trans_exc_code;
+ tec_bits->fsi = write ? FSI_STORE : FSI_FETCH;
+ tec_bits->as = psw_bits(*psw).as;
+
+ if (!psw_bits(*psw).t) {
+ asce->val = 0;
+ asce->r = 1;
+ return 0;
+ }
+
+ switch (psw_bits(vcpu->arch.sie_block->gpsw).as) {
+ case PSW_AS_PRIMARY:
+ asce->val = vcpu->arch.sie_block->gcr[1];
+ return 0;
+ case PSW_AS_SECONDARY:
+ asce->val = vcpu->arch.sie_block->gcr[7];
+ return 0;
+ case PSW_AS_HOME:
+ asce->val = vcpu->arch.sie_block->gcr[13];
+ return 0;
+ case PSW_AS_ACCREG:
+ rc = ar_translation(vcpu, asce, ar, write);
+ switch (rc) {
+ case PGM_ALEN_TRANSLATION:
+ case PGM_ALE_SEQUENCE:
+ case PGM_ASTE_VALIDITY:
+ case PGM_ASTE_SEQUENCE:
+ case PGM_EXTENDED_AUTHORITY:
+ vcpu->arch.pgm.exc_access_id = ar;
+ break;
+ case PGM_PROTECTION:
+ tec_bits->b60 = 1;
+ tec_bits->b61 = 1;
+ break;
+ }
+ if (rc > 0)
+ pgm->code = rc;
+ 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
+ * @write: indicates if access is a write access
+ *
+ * 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,
+ int write)
+{
+ union vaddress vaddr = {.addr = gva};
+ union raddress raddr = {.addr = gva};
+ union page_table_entry pte;
+ int dat_protection = 0;
+ union ctlreg0 ctlreg0;
+ unsigned long ptr;
+ int edat1, edat2;
+
+ 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);
+ if (asce.r)
+ goto real_address;
+ ptr = asce.origin * 4096;
+ 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 * 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;
+}