From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [patch] x86, kvm: fix build failure with CONFIG_SMP disabled Date: Wed, 17 Apr 2013 17:47:07 -0700 Message-ID: <516F428B.7010900@infradead.org> References: <20130417170450.5dd6e5f450de4d5bf197d997@canb.auug.org.au> <516EE5AB.4080201@infradead.org> <516F37FF.8040703@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from casper.infradead.org ([85.118.1.10]:51059 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935627Ab3DRArZ (ORCPT ); Wed, 17 Apr 2013 20:47:25 -0400 In-Reply-To: Sender: linux-next-owner@vger.kernel.org List-ID: To: "Zhang, Yang Z" Cc: David Rientjes , Marcelo Tosatti , Gleb Natapov , Stephen Rothwell , "x86@kernel.org" , "linux-next@vger.kernel.org" , "linux-kernel@vger.kernel.org" , KVM On 04/17/13 17:35, Zhang, Yang Z wrote: > David Rientjes wrote on 2013-04-18: >> On Wed, 17 Apr 2013, Randy Dunlap wrote: >> >>> On 04/17/13 16:12, David Rientjes wrote: >>>> The build fails when CONFIG_SMP is disabled: >>>> >>>> arch/x86/kvm/vmx.c: In function 'vmx_deliver_posted_interrupt': >>>> arch/x86/kvm/vmx.c:3950:3: error: 'apic' undeclared (first use in >>>> this function) >>>> >>>> Fix it by including the necessary header. >>> >>> Sorry, i386 build still fails with the same error message plus this one: >>> >>> ERROR: "apic" [arch/x86/kvm/kvm-intel.ko] undefined! >>> >> >> Ahh, that's because you don't have CONFIG_X86_LOCAL_APIC as you already >> mentioned. So it looks like this error can manifest in two different ways >> and we got different reports. >> >> This failure came from "KVM: VMX: Add the deliver posted interrupt >> algorithm", so adding Yang to the cc to specify the dependency this has on >> apic and how it can be protected without CONFIG_X86_LOCAL_APIC on i386. > How about the follow patch? > > commit a49dd819f502c1029c5a857e87201ef25ec06ce6 > Author: Yang Zhang > Date: Wed Apr 17 05:34:07 2013 -0400 > > KVM: x86: Don't sending posted interrupt if not config CONFIG_SMP > > In UP, posted interrupt logic will not work. So we should not send > posted interrupt and let vcpu to pick the pending interrupt before > vmentry. > > Signed-off-by: Yang Zhang Missing Reported-by: and the patch does not apply cleanly (looks like lots of spaces instead of tabs in it)... but it does build now after massaging the patch. Thanks. Acked-by: Randy Dunlap > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 52b21da..d5c6b95 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -3946,10 +3946,12 @@ static void vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector) > > r = pi_test_and_set_on(&vmx->pi_desc); > kvm_make_request(KVM_REQ_EVENT, vcpu); > +#ifdef CONFIG_SMP > if (!r && (vcpu->mode == IN_GUEST_MODE)) > apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), > POSTED_INTR_VECTOR); > else > +#endif > kvm_vcpu_kick(vcpu); > } > > Best regards, > Yang > > -- ~Randy