From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752476AbdCBMki (ORCPT ); Thu, 2 Mar 2017 07:40:38 -0500 Received: from victor.provo.novell.com ([137.65.250.26]:33655 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500AbdCBMkc (ORCPT ); Thu, 2 Mar 2017 07:40:32 -0500 Subject: Re: [PATCH 2/2] vfio: type1: conditionally check MSI remapping at irq domain level To: Auger Eric , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, marc.zyngier@arm.com, alex.williamson@redhat.com Cc: will.deacon@arm.com References: <20170302100132.20502-1-yousaf.kaukab@suse.com> <20170302100132.20502-2-yousaf.kaukab@suse.com> <164781c3-af63-b3a1-332f-420b54384b5f@redhat.com> From: Mian Yousaf Kaukab Message-ID: <4304c447-0523-08a0-3327-e974bedc3c73@suse.com> Date: Thu, 2 Mar 2017 13:38:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.0 MIME-Version: 1.0 In-Reply-To: <164781c3-af63-b3a1-332f-420b54384b5f@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/02/2017 11:24 AM, Auger Eric wrote: > Hi, > > On 02/03/2017 11:01, Mian Yousaf Kaukab wrote: >> Check only if irq domains are available. >> >> Signed-off-by: Mian Yousaf Kaukab >> --- >> drivers/vfio/vfio_iommu_type1.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c >> index bd6f293c4ebd..e3ed50e40ead 100644 >> --- a/drivers/vfio/vfio_iommu_type1.c >> +++ b/drivers/vfio/vfio_iommu_type1.c >> @@ -1287,8 +1287,9 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, >> INIT_LIST_HEAD(&domain->group_list); >> list_add(&group->next, &domain->group_list); >> >> - msi_remap = resv_msi ? irq_domain_check_msi_remap() : >> - iommu_capable(bus, IOMMU_CAP_INTR_REMAP); >> + msi_remap = resv_msi && IS_ENABLED(CONFIG_IRQ_DOMAIN) ? >> + irq_domain_check_msi_remap() : >> + iommu_capable(bus, IOMMU_CAP_INTR_REMAP); > Is that patch actually needed after [PATCH 1/2] irqdomain: add empty > irq_domain_check_msi_remap. irq_domain_check_msi_remap() should be > defined and if you follow my suggestion, would return false. Anyway in > your case resv_msi should be false. I agree its an overkill if resv_msi is guaranteed to be false. What I am unsure about is that, if iommu have IOMMU_RESV_MSI regions that would mean that irq domains are selected in the build. If this is not guaranteed, then we need to add this check. > > Thanks > > Eric BR, Yousaf