From: Alexander Yarygin <yarygin@xxxxxxxxxxxxxxxxxx>
Access register mode is one of the modes that control dynamic address
translation. In this mode the address space is specified by values of
the access registers. The effective address-space-control element is
obtained from the result of the access register translation. See
the "Access-Register Introduction" section of the chapter 5 "Program
Execution" in "Principles of Operations" for more details.
Signed-off-by: Alexander Yarygin <yarygin@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/kvm/gaccess.c | 234 +++++++++++++++++++++++++++++++++++++++++-------
arch/s390/kvm/gaccess.h | 3 +-
2 files changed, 202 insertions(+), 35 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index c74462a..ea38d71 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -10,6 +10,7 @@
#include <asm/pgtable.h>
#include "kvm-s390.h"
#include "gaccess.h"
+#include <asm/switch_to.h>
union asce {
unsigned long val;
@@ -207,6 +208,54 @@ union raddress {
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)
{
@@ -307,15 +356,157 @@ void ipte_unlock(struct kvm_vcpu *vcpu)
ipte_unlock_simple(vcpu);
}
-static unsigned long get_vcpu_asce(struct kvm_vcpu *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:
- return vcpu->arch.sie_block->gcr[1];
+ asce->val = vcpu->arch.sie_block->gcr[1];
+ return 0;
case PSW_AS_SECONDARY:
- return vcpu->arch.sie_block->gcr[7];
+ asce->val = vcpu->arch.sie_block->gcr[7];
+ return 0;
case PSW_AS_HOME:
- return vcpu->arch.sie_block->gcr[13];
+ 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;
}
@@ -519,20 +710,6 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
return 1;
}
-struct trans_exc_code_bits {
- unsigned long addr : 52; /* Translation-exception Address */
- unsigned long fsi : 2; /* Access Exception Fetch/Store Indication */
- unsigned long : 7;
- 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 guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
unsigned long *pages, unsigned long nr_pages,
const union asce asce, int write)
@@ -542,10 +719,7 @@ static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga,
struct trans_exc_code_bits *tec_bits;
int lap_enabled, rc;
- 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;
lap_enabled = low_address_protection_enabled(vcpu, asce);
while (nr_pages) {
ga = kvm_s390_logical_to_effective(vcpu, ga);
@@ -590,16 +764,15 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
if (!len)
return 0;
- /* Access register mode is not supported yet. */
- if (psw_bits(*psw).t && psw_bits(*psw).as == PSW_AS_ACCREG)
- return -EOPNOTSUPP;
+ 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;
- asce.val = get_vcpu_asce(vcpu);
need_ipte_lock = psw_bits(*psw).t && !asce.r;
if (need_ipte_lock)
ipte_lock(vcpu);
@@ -660,17 +833,12 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
union asce asce;
int rc;
- /* Access register mode is not supported yet. */
- if (psw_bits(*psw).t && psw_bits(*psw).as == PSW_AS_ACCREG)
- return -EOPNOTSUPP;
-
gva = kvm_s390_logical_to_effective(vcpu, gva);
- memset(pgm, 0, sizeof(*pgm));
tec = (struct trans_exc_code_bits *)&pgm->trans_exc_code;
- tec->as = psw_bits(*psw).as;
- tec->fsi = write ? FSI_STORE : FSI_FETCH;
+ rc = get_vcpu_asce(vcpu, &asce, ar, write);
tec->addr = gva >> PAGE_SHIFT;
- asce.val = get_vcpu_asce(vcpu);
+ if (rc)
+ return rc;
if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {
if (write) {
rc = pgm->code = PGM_PROTECTION;
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 7c2866b..835e557 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -177,8 +177,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
* If DAT is off data will be copied to guest real or absolute memory.
* If DAT is on data will be copied to the address space as specified by
* the address space bits of the PSW:
- * Primary, secondory or home space (access register mode is currently not
- * implemented).
+ * Primary, secondary, home space or access register mode.
* The addressing mode of the PSW is also inspected, so that address wrap
* around is taken into account for 24-, 31- and 64-bit addressing mode,
* if the to be copied data crosses page boundaries in guest address space.
--
2.3.0
--
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