On Tue, Oct 19, 2010 at 01:05:22PM +0200, Gleb Natapov wrote: > On Mon, Oct 18, 2010 at 08:24:03PM -0200, Marcelo Tosatti wrote: > > > > Only attempt async pagefault if address is contained within vma. > > > > Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> > > > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index 5d57ec9..a9cfbd2 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -996,8 +996,9 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, > > > > if (vma == NULL || addr < vma->vm_start || > > !(vma->vm_flags & VM_PFNMAP)) { > > - if (async && !(vma->vm_flags & VM_PFNMAP) && > > - (vma->vm_flags & VM_WRITE)) > > + if (async && vma && !(vma->vm_flags & VM_PFNMAP) && > actually we should check for addr < vma->vm_start here too. find_vma() > is very strange function. > > What about patch below (only compile tested for now)? > Works for me. > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 796b06e..29e40e5 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -954,6 +954,12 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) > } > EXPORT_SYMBOL_GPL(gfn_to_hva); > > +static pfn_t get_fault_pfn(void) > +{ > + get_page(fault_page); > + return fault_pfn; > +} > + > static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, > bool *async) > { > @@ -983,7 +989,7 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, > struct vm_area_struct *vma; > > if (atomic) > - goto return_fault_page; > + return get_fault_pfn(); > > down_read(¤t->mm->mmap_sem); > if (is_hwpoison_address(addr)) { > @@ -992,22 +998,20 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic, > return page_to_pfn(hwpoison_page); > } > > - vma = find_vma(current->mm, addr); > + vma = find_vma_intersection(current->mm, addr, addr+1); > > - if (vma == NULL || addr < vma->vm_start || > - !(vma->vm_flags & VM_PFNMAP)) { > - if (async && !(vma->vm_flags & VM_PFNMAP) && > - (vma->vm_flags & VM_WRITE)) > + if (vma == NULL) > + return get_fault_pfn(); > + if ((vma->vm_flags & VM_PFNMAP)) { > + pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + > + vma->vm_pgoff; > + BUG_ON(!kvm_is_mmio_pfn(pfn)); > + } else { > + if (async && (vma->vm_flags & VM_WRITE)) > *async = true; > - up_read(¤t->mm->mmap_sem); > -return_fault_page: > - get_page(fault_page); > - return page_to_pfn(fault_page); > + pfn = get_fault_pfn(); > } > - > - pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; > up_read(¤t->mm->mmap_sem); > - BUG_ON(!kvm_is_mmio_pfn(pfn)); > } else > pfn = page_to_pfn(page[0]); > > -- > Gleb. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html