On 09/02/2018 08:14, Cédric Le Goater wrote:
>>> @@ -402,8 +450,15 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
>>> vma = find_vma(current->mm, hva);
>>> if (vma && vma->vm_start <= hva && hva < vma->vm_end &&
>>> (vma->vm_flags & VM_PFNMAP)) {
>>> - pfn = vma->vm_pgoff +
>>> - ((hva - vma->vm_start) >> PAGE_SHIFT);
>>> + if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
>>> + ret = hva_to_pfn_remapped(vma, hva, writing,
>>> + &pfn);
>>> + if (ret == -EAGAIN)
>>> + return RESUME_GUEST;
>>> + } else {
>>> + pfn = vma->vm_pgoff +
>>> + ((hva - vma->vm_start) >> PAGE_SHIFT);
>>> + }
>> I don't think the else case is useful. If fact you are checking
>> VM_PFNMAP twice...
> yes. I am not sure what the VM_PFNMAP case does. The code comes
> from kvmppc_book3s_hv_page_fault() I suppose.
Maybe the outer check should be for VM_IO|VM_PFNMAP?
(Also, why is this code reinventing most of hva_to_pfn? Not asking you
to fix that of course, but perhaps there's something to improve in the
generic code too).
Thanks,
Paolo
