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KVM: s390: Add a generic function for translating guest addresses

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This patch adds a function for translating logical guest addresses into
physical guest addresses without touching the memory at the given location.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
This commit is contained in:
Thomas Huth 2014-02-04 14:43:25 +01:00 committed by Christian Borntraeger
parent 1f85411255
commit 9fbc02760d
2 changed files with 56 additions and 0 deletions
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53
arch/s390/kvm/gaccess.c
View File

@ -644,6 +644,59 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
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,
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;
/* 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;
tec->addr = gva >> PAGE_SHIFT;
if (is_low_address(gva) && low_address_protection_enabled(vcpu)) {
if (write) {
rc = pgm->code = PGM_PROTECTION;
return rc;
}
}
asce.val = get_vcpu_asce(vcpu);
if (psw_bits(*psw).t && !asce.r) { /* Use DAT? */
rc = guest_translate(vcpu, gva, gpa, 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;
}
/**
* kvm_s390_check_low_addr_protection - check for low-address protection
* @ga: Guest address

3
arch/s390/kvm/gaccess.h
View File

@ -155,6 +155,9 @@ int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
return kvm_read_guest(vcpu->kvm, gpa, data, len);
}
int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
unsigned long *gpa, int write);
int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
unsigned long len, int write);