On Mon, Oct 15, 2018 at 07:15:44PM +0200, Paolo Bonzini wrote: >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). > Reasonable, thanks for your comment. >Paolo -- Wei Yang Help you, Help me
