From patchwork Tue Dec 6 09:43:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 703067 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3tXxdW1CKLz9sR9 for ; Tue, 6 Dec 2016 20:48:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752113AbcLFJoD (ORCPT ); Tue, 6 Dec 2016 04:44:03 -0500 Received: from ozlabs.org ([103.22.144.67]:33749 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751610AbcLFJoB (ORCPT ); Tue, 6 Dec 2016 04:44:01 -0500 Received: by ozlabs.org (Postfix, from userid 1003) id 3tXxXD0BsGz9t0v; Tue, 6 Dec 2016 20:43:39 +1100 (AEDT) Date: Tue, 6 Dec 2016 20:43:37 +1100 From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Subject: [PATCH] KVM: PPC: Book3S HV: Fix H_PROD to actually wake the target vcpu Message-ID: <20161206094337.GC25458@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The H_PROD hypercall is supposed to wake up an idle vcpu. We have an implementation, but because Linux doesn't use it except when doing cpu hotplug, it was never tested properly. AIX does use it, and reported it broken. It turns out we were waking the wrong vcpu (the one doing H_PROD, not the target of the prod) and we weren't handling the case where the target needs an IPI to wake it. Fix it by using the existing kvmppc_fast_vcpu_kick_hv() function, which is intended for this kind of thing, and by using the target vcpu not the current vcpu. Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index be8f83c..03070cd 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -773,12 +773,8 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) } tvcpu->arch.prodded = 1; smp_mb(); - if (vcpu->arch.ceded) { - if (swait_active(&vcpu->wq)) { - swake_up(&vcpu->wq); - vcpu->stat.halt_wakeup++; - } - } + if (tvcpu->arch.ceded) + kvmppc_fast_vcpu_kick_hv(tvcpu); break; case H_CONFER: target = kvmppc_get_gpr(vcpu, 4);