diff mbox series

[v7,09/17] KVM: s390: pv: clear the state without memset

Message ID 20220204155349.63238-10-imbrenda@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series KVM: s390: pv: implement lazy destroy for reboot | expand

Commit Message

Claudio Imbrenda Feb. 4, 2022, 3:53 p.m. UTC
Do not use memset to clean the whole struct kvm_s390_pv; instead,
explicitly clear the fields that need to be cleared.

Upcoming patches will introduce new fields in the struct kvm_s390_pv
that will not need to be cleared.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/kvm/pv.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Janosch Frank Feb. 7, 2022, 10:09 a.m. UTC | #1
On 2/4/22 16:53, Claudio Imbrenda wrote:
> Do not use memset to clean the whole struct kvm_s390_pv; instead,
> explicitly clear the fields that need to be cleared.
> 
> Upcoming patches will introduce new fields in the struct kvm_s390_pv
> that will not need to be cleared.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>   arch/s390/kvm/pv.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
> index 9e900ce7387d..f1e812a45acb 100644
> --- a/arch/s390/kvm/pv.c
> +++ b/arch/s390/kvm/pv.c
> @@ -16,6 +16,15 @@
>   #include <linux/sched/mm.h>
>   #include "kvm-s390.h"
>   
> +static void kvm_s390_clear_pv_state(struct kvm *kvm)
> +{
> +	kvm->arch.pv.handle = 0;
> +	kvm->arch.pv.guest_len = 0;
> +	kvm->arch.pv.stor_base = 0;
> +	kvm->arch.pv.stor_var = NULL;
> +	kvm->arch.pv.handle = 0;

You really want to make sure the handle is zero :)

With this fixed:
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

> +}
> +
>   int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
>   {
>   	int cc;
> @@ -110,7 +119,7 @@ static void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
>   	vfree(kvm->arch.pv.stor_var);
>   	free_pages(kvm->arch.pv.stor_base,
>   		   get_order(uv_info.guest_base_stor_len));
> -	memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv));
> +	kvm_s390_clear_pv_state(kvm);
>   }
>   
>   static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
>
diff mbox series

Patch

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 9e900ce7387d..f1e812a45acb 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -16,6 +16,15 @@ 
 #include <linux/sched/mm.h>
 #include "kvm-s390.h"
 
+static void kvm_s390_clear_pv_state(struct kvm *kvm)
+{
+	kvm->arch.pv.handle = 0;
+	kvm->arch.pv.guest_len = 0;
+	kvm->arch.pv.stor_base = 0;
+	kvm->arch.pv.stor_var = NULL;
+	kvm->arch.pv.handle = 0;
+}
+
 int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
 {
 	int cc;
@@ -110,7 +119,7 @@  static void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
 	vfree(kvm->arch.pv.stor_var);
 	free_pages(kvm->arch.pv.stor_base,
 		   get_order(uv_info.guest_base_stor_len));
-	memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv));
+	kvm_s390_clear_pv_state(kvm);
 }
 
 static int kvm_s390_pv_alloc_vm(struct kvm *kvm)