On 07/04/2015 22:34, Radim Krčmář wrote: > We dirtied only one page because writes originally couldn't span more. > Use improved syntax for '>> PAGE_SHIFT' while at it. > > Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.") > Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx> Cross-page reads and writes should never get here; they have ghc->memslot set to NULL and go through the slow path in kvm_write_guest. What am I missing? Paolo > --- > The function handles cross memslot writes in a different path. > > I think we should dirty pages after partial writes too (r < len), > but it probably won't happen and I already started refactoring :) > > virt/kvm/kvm_main.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index aadef264bed1..863df9dcab6f 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1665,6 +1665,7 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, > { > struct kvm_memslots *slots = kvm_memslots(kvm); > int r; > + gfn_t gfn; > > BUG_ON(len > ghc->len); > > @@ -1680,7 +1681,10 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, > r = __copy_to_user((void __user *)ghc->hva, data, len); > if (r) > return -EFAULT; > - mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT); > + > + for (gfn = gpa_to_gfn(ghc->gpa); > + gfn <= gpa_to_gfn(ghc->gpa + len - 1); gfn++) > + mark_page_dirty_in_slot(kvm, ghc->memslot, gfn); > > return 0; > } > -- 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