On 16/09/2018 10:07, Wei Yang wrote: > Here is the code flow related to mmu_pages_first(): > > mmu_unsync_walk() > mmu_pages_add() > __mmu_unsync_walk() > for_each_sp() > mmu_pages_first() > > Every time when mmu_pages_first() is invoked, pvec is prepared by > mmu_unsync_walk() which insert at least one sp in pvec. > > This patch removes the check on pvec->nr since this doesn't happen. > > Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> > --- > arch/x86/kvm/mmu.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 899c029cff0d..0caaaa25e88b 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2267,9 +2267,6 @@ static int mmu_pages_first(struct kvm_mmu_pages *pvec, > struct kvm_mmu_page *sp; > int level; > > - if (pvec->nr == 0) > - return 0; > - > WARN_ON(pvec->page[0].idx != INVALID_INDEX); > > sp = pvec->page[0].sp; > It's harmless and it may not be the case in the future for other uses of for_each_sp, so I'd rather leave it here (anyway I'd change it to a WARN_ON, not remove it altogether). Paolo
