I am dropping this patch based on our conversation, where we agreed, we
need to rootcause the migration failure.
On Thu, Jul 23, 2020 at 11:43:44AM +0530, Bharata B Rao wrote:
> On Fri, Jul 17, 2020 at 01:00:26AM -0700, Ram Pai wrote:
> > @@ -812,7 +842,7 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
> > unsigned long gpa,
> > struct vm_area_struct *vma;
> > int srcu_idx;
> > unsigned long gfn = gpa >> page_shift;
> > - int ret;
> > + int ret, repeat_count = REPEAT_COUNT;
> >
> > if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
> > return H_UNSUPPORTED;
> > @@ -826,34 +856,44 @@ unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
> > unsigned long gpa,
> > if (flags & H_PAGE_IN_SHARED)
> > return kvmppc_share_page(kvm, gpa, page_shift);
> >
> > - ret = H_PARAMETER;
> > srcu_idx = srcu_read_lock(&kvm->srcu);
> > - mmap_read_lock(kvm->mm);
> >
> > - start = gfn_to_hva(kvm, gfn);
> > - if (kvm_is_error_hva(start))
> > - goto out;
> > -
> > - mutex_lock(&kvm->arch.uvmem_lock);
> > /* Fail the page-in request of an already paged-in page */
> > - if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL))
> > - goto out_unlock;
> > + mutex_lock(&kvm->arch.uvmem_lock);
> > + ret = kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL);
> > + mutex_unlock(&kvm->arch.uvmem_lock);
>
> Same comment as for the prev patch. I don't think you can release
> the lock here.
>
> > + if (ret) {
> > + srcu_read_unlock(&kvm->srcu, srcu_idx);
> > + return H_PARAMETER;
> > + }
> >
> > - end = start + (1UL << page_shift);
> > - vma = find_vma_intersection(kvm->mm, start, end);
> > - if (!vma || vma->vm_start > start || vma->vm_end < end)
> > - goto out_unlock;
> > + do {
> > + ret = H_PARAMETER;
> > + mmap_read_lock(kvm->mm);
> >
> > - if (kvmppc_svm_migrate_page(vma, start, end, gpa, kvm, page_shift,
> > - true))
> > - goto out_unlock;
> > + start = gfn_to_hva(kvm, gfn);
> > + if (kvm_is_error_hva(start)) {
> > + mmap_read_unlock(kvm->mm);
> > + break;
> > + }
> >
> > - ret = H_SUCCESS;
> > + end = start + (1UL << page_shift);
> > + vma = find_vma_intersection(kvm->mm, start, end);
> > + if (!vma || vma->vm_start > start || vma->vm_end < end) {
> > + mmap_read_unlock(kvm->mm);
> > + break;
> > + }
> > +
> > + mutex_lock(&kvm->arch.uvmem_lock);
> > + ret = kvmppc_svm_migrate_page(vma, start, end, gpa, kvm,
> > page_shift, true);
> > + mutex_unlock(&kvm->arch.uvmem_lock);
> > +
> > + mmap_read_unlock(kvm->mm);
> > + } while (ret == -2 && repeat_count--);
> > +
> > + if (ret == -2)
> > + ret = H_BUSY;
> >
> > -out_unlock:
> > - mutex_unlock(&kvm->arch.uvmem_lock);
> > -out:
> > - mmap_read_unlock(kvm->mm);
> > srcu_read_unlock(&kvm->srcu, srcu_idx);
> > return ret;
> > }
> > --
> > 1.8.3.1
--
Ram Pai
