Re: [PATCH v7 10/14] KVM: s390: Refactor absolute vm mem_op function

Janosch Frank
2023-02-07T13:22:55Z

On 2/6/23 17:45, Janis Schoetterl-Glausch wrote:
> Remove code duplication with regards to the CHECK_ONLY flag.
> Decrease the number of indents.
> No functional change indented.
>
> Suggested-by: Janosch Frank <frankja@linux.ibm.com>
> Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
>

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

>
> Cosmetic only, can be dropped
>
>
> arch/s390/kvm/kvm-s390.c | 43 +++++++++++++++++-----------------------
> 1 file changed, 18 insertions(+), 25 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 707967a296f1..1f94b18f1cb5 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2782,6 +2782,7 @@ static int mem_op_validate_common(struct kvm_s390_mem_op *mop, u64 supported_fla
> static int kvm_s390_vm_mem_op_abs(struct kvm *kvm, struct kvm_s390_mem_op *mop)
> {
> void __user *uaddr = (void __user *)mop->buf;
> + enum gacc_mode acc_mode;
> void *tmpbuf = NULL;
> int r, srcu_idx;
>
> @@ -2803,33 +2804,25 @@ static int kvm_s390_vm_mem_op_abs(struct kvm *kvm, struct kvm_s390_mem_op *mop)
> goto out_unlock;
> }
>
> - switch (mop->op) {
> - case KVM_S390_MEMOP_ABSOLUTE_READ: {
> - if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
> - r = check_gpa_range(kvm, mop->gaddr, mop->size, GACC_FETCH, mop->key);
> - } else {
> - r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
> - mop->size, GACC_FETCH, mop->key);
> - if (r == 0) {
> - if (copy_to_user(uaddr, tmpbuf, mop->size))
> - r = -EFAULT;
> - }
> - }
> - break;
> + acc_mode = mop->op == KVM_S390_MEMOP_ABSOLUTE_READ ? GACC_FETCH : GACC_STORE;
> + if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
> + r = check_gpa_range(kvm, mop->gaddr, mop->size, acc_mode, mop->key);
> + goto out_unlock;
> }
> - case KVM_S390_MEMOP_ABSOLUTE_WRITE: {
> - if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
> - r = check_gpa_range(kvm, mop->gaddr, mop->size, GACC_STORE, mop->key);
> - } else {
> - if (copy_from_user(tmpbuf, uaddr, mop->size)) {
> - r = -EFAULT;
> - break;
> - }
> - r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
> - mop->size, GACC_STORE, mop->key);
> + if (acc_mode == GACC_FETCH) {
> + r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
> + mop->size, GACC_FETCH, mop->key);
> + if (r)
> + goto out_unlock;
> + if (copy_to_user(uaddr, tmpbuf, mop->size))
> + r = -EFAULT;
> + } else {
> + if (copy_from_user(tmpbuf, uaddr, mop->size)) {
> + r = -EFAULT;
> + goto out_unlock;
> }
> - break;
> - }
> + r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
> + mop->size, GACC_STORE, mop->key);
> }
>