On 02/02/19 10:20, lantianyu1986@xxxxxxxxx wrote: > From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx> > > The value of "dirty_bitmap[i]" is already check before setting its value > to mask. The following check of "mask" is redundant. The check of "mask" was > introduced by commit 58d2930f4ee3(("KVM: Eliminate extra function calls in > kvm_get_dirty_log_protect()"). This patch is to revert the patch. > > Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx> > --- > virt/kvm/kvm_main.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 2bdc827b9ee9..ef06cfb9b52b 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1200,11 +1200,9 @@ int kvm_get_dirty_log_protect(struct kvm *kvm, > mask = xchg(&dirty_bitmap[i], 0); > dirty_bitmap_buffer[i] = mask; > > - if (mask) { > - offset = i * BITS_PER_LONG; > - kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, > - offset, mask); > - } > + offset = i * BITS_PER_LONG; > + kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, > + offset, mask); > } > spin_unlock(&kvm->mmu_lock); > } > Queued, thanks. Paolo