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KVM: s390: gaccess: Refactor gpa and length calculation

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Improve readability by renaming the length variable and
not calculating the offset manually.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20211126164549.7046-2-scgl@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
This commit is contained in:
Janis Schoetterl-Glausch
2021-11-26 17:45:47 +01:00
committed by Janosch Frank
parent 49ae248b61
commit 416e7f0c9d
1 changed files with 17 additions and 15 deletions
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32
arch/s390/kvm/gaccess.c
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@ -831,8 +831,9 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
unsigned long len, enum gacc_mode mode) unsigned long len, enum gacc_mode mode)
{ {
psw_t *psw = &vcpu->arch.sie_block->gpsw; psw_t *psw = &vcpu->arch.sie_block->gpsw;
unsigned long _len, nr_pages, gpa, idx; unsigned long nr_pages, gpa, idx;
unsigned long pages_array[2]; unsigned long pages_array[2];
unsigned int fragment_len;
unsigned long *pages; unsigned long *pages;
int need_ipte_lock; int need_ipte_lock;
union asce asce; union asce asce;
@ -855,15 +856,15 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
ipte_lock(vcpu); ipte_lock(vcpu);
rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode); rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode);
for (idx = 0; idx < nr_pages && !rc; idx++) { for (idx = 0; idx < nr_pages && !rc; idx++) {
gpa = *(pages + idx) + (ga & ~PAGE_MASK); gpa = pages[idx] + offset_in_page(ga);
_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
if (mode == GACC_STORE) if (mode == GACC_STORE)
rc = kvm_write_guest(vcpu->kvm, gpa, data, _len); rc = kvm_write_guest(vcpu->kvm, gpa, data, fragment_len);
else else
rc = kvm_read_guest(vcpu->kvm, gpa, data, _len); rc = kvm_read_guest(vcpu->kvm, gpa, data, fragment_len);
len -= _len; len -= fragment_len;
ga += _len; ga += fragment_len;
data += _len; data += fragment_len;
} }
if (need_ipte_lock) if (need_ipte_lock)
ipte_unlock(vcpu); ipte_unlock(vcpu);
@ -875,19 +876,20 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
void *data, unsigned long len, enum gacc_mode mode) void *data, unsigned long len, enum gacc_mode mode)
{ {
unsigned long _len, gpa; unsigned int fragment_len;
unsigned long gpa;
int rc = 0; int rc = 0;
while (len && !rc) { while (len && !rc) {
gpa = kvm_s390_real_to_abs(vcpu, gra); gpa = kvm_s390_real_to_abs(vcpu, gra);
_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len); fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
if (mode) if (mode)
rc = write_guest_abs(vcpu, gpa, data, _len); rc = write_guest_abs(vcpu, gpa, data, fragment_len);
else else
rc = read_guest_abs(vcpu, gpa, data, _len); rc = read_guest_abs(vcpu, gpa, data, fragment_len);
len -= _len; len -= fragment_len;
gra += _len; gra += fragment_len;
data += _len; data += fragment_len;
} }
return rc; return rc;
} }