diff mbox series

[v3,1/3] KVM: s390: gaccess: Refactor gpa and length calculation

Message ID 20211126164549.7046-2-scgl@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series KVM: s390: Some gaccess cleanup | expand

Commit Message

Janis Schoetterl-Glausch Nov. 26, 2021, 4:45 p.m. UTC
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>
---
 arch/s390/kvm/gaccess.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

Comments

David Hildenbrand Nov. 26, 2021, 5:10 p.m. UTC | #1
On 26.11.21 17:45, Janis Schoetterl-Glausch wrote:
> 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>
> ---
>  arch/s390/kvm/gaccess.c | 32 +++++++++++++++++---------------
>  1 file changed, 17 insertions(+), 15 deletions(-)

Reviewed-by: David Hildenbrand <david@redhat.com>
Claudio Imbrenda Nov. 29, 2021, 8:55 a.m. UTC | #2
On Fri, 26 Nov 2021 17:45:47 +0100
Janis Schoetterl-Glausch <scgl@linux.ibm.com> wrote:

> 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: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  arch/s390/kvm/gaccess.c | 32 +++++++++++++++++---------------
>  1 file changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
> index 6af59c59cc1b..45966fbba182 100644
> --- a/arch/s390/kvm/gaccess.c
> +++ b/arch/s390/kvm/gaccess.c
> @@ -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)
>  {
>  	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 int fragment_len;
>  	unsigned long *pages;
>  	int need_ipte_lock;
>  	union asce asce;
> @@ -855,15 +856,15 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
>  		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);
> +		gpa = pages[idx] + offset_in_page(ga);
> +		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
>  		if (mode == GACC_STORE)
> -			rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);
> +			rc = kvm_write_guest(vcpu->kvm, gpa, data, fragment_len);
>  		else
> -			rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
> -		len -= _len;
> -		ga += _len;
> -		data += _len;
> +			rc = kvm_read_guest(vcpu->kvm, gpa, data, fragment_len);
> +		len -= fragment_len;
> +		ga += fragment_len;
> +		data += fragment_len;
>  	}
>  	if (need_ipte_lock)
>  		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,
>  		      void *data, unsigned long len, enum gacc_mode mode)
>  {
> -	unsigned long _len, gpa;
> +	unsigned int fragment_len;
> +	unsigned long gpa;
>  	int rc = 0;
>  
>  	while (len && !rc) {
>  		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)
> -			rc = write_guest_abs(vcpu, gpa, data, _len);
> +			rc = write_guest_abs(vcpu, gpa, data, fragment_len);
>  		else
> -			rc = read_guest_abs(vcpu, gpa, data, _len);
> -		len -= _len;
> -		gra += _len;
> -		data += _len;
> +			rc = read_guest_abs(vcpu, gpa, data, fragment_len);
> +		len -= fragment_len;
> +		gra += fragment_len;
> +		data += fragment_len;
>  	}
>  	return rc;
>  }
diff mbox series

Patch

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 6af59c59cc1b..45966fbba182 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -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)
 {
 	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 int fragment_len;
 	unsigned long *pages;
 	int need_ipte_lock;
 	union asce asce;
@@ -855,15 +856,15 @@  int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 		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);
+		gpa = pages[idx] + offset_in_page(ga);
+		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
 		if (mode == GACC_STORE)
-			rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);
+			rc = kvm_write_guest(vcpu->kvm, gpa, data, fragment_len);
 		else
-			rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
-		len -= _len;
-		ga += _len;
-		data += _len;
+			rc = kvm_read_guest(vcpu->kvm, gpa, data, fragment_len);
+		len -= fragment_len;
+		ga += fragment_len;
+		data += fragment_len;
 	}
 	if (need_ipte_lock)
 		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,
 		      void *data, unsigned long len, enum gacc_mode mode)
 {
-	unsigned long _len, gpa;
+	unsigned int fragment_len;
+	unsigned long gpa;
 	int rc = 0;
 
 	while (len && !rc) {
 		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)
-			rc = write_guest_abs(vcpu, gpa, data, _len);
+			rc = write_guest_abs(vcpu, gpa, data, fragment_len);
 		else
-			rc = read_guest_abs(vcpu, gpa, data, _len);
-		len -= _len;
-		gra += _len;
-		data += _len;
+			rc = read_guest_abs(vcpu, gpa, data, fragment_len);
+		len -= fragment_len;
+		gra += fragment_len;
+		data += fragment_len;
 	}
 	return rc;
 }