Messages in this thread | | | Date | Fri, 3 Feb 2023 15:48:55 +0100 | From | Janosch Frank <> | Subject | Re: [PATCH v6 10/14] KVM: s390: Refactor absolute vm mem_op function |
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On 1/25/23 22:26, 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> > --- > > > Cosmetic only, can be dropped. > > > arch/s390/kvm/kvm-s390.c | 43 ++++++++++++++++------------------------ > 1 file changed, 17 insertions(+), 26 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 588cf70dc81e..cfd09cb43ef6 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -2794,6 +2794,7 @@ static void *mem_op_alloc_buf(struct kvm_s390_mem_op *mop) > 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; > > @@ -2813,33 +2814,23 @@ 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; > - } > - 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); > + acc_mode = mop->op == KVM_S390_MEMOP_ABSOLUTE_READ ? GACC_FETCH : GACC_STORE;
Would the line be too long if that variable would be initialized where it's defined?
> + if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) { > + r = check_gpa_range(kvm, mop->gaddr, mop->size, acc_mode, mop->key);
We should early return i.e. goto out_unlock.
IMHO else if, else patterns should either be switches (testing the same variable) or kept as short as possible / be avoided.
> + } else if (acc_mode == GACC_FETCH) { > + r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf, > + mop->size, GACC_FETCH, mop->key);
I'd guess it's personal taste whether you use GACC_FETCH or access_mode but if you don't use it here then we can remove the variable all together, no?
> + 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); > } > > out_unlock:
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