From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 278241A184E for ; Sat, 23 Jan 2016 04:24:22 +1100 (AEDT) Message-ID: <1453483460.32741.420.camel@redhat.com> Subject: Re: [PATCH kernel] vfio: Only check for bus IOMMU when NOIOMMU is selected From: Alex Williamson To: Alexey Kardashevskiy , linuxppc-dev@lists.ozlabs.org Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 22 Jan 2016 10:24:20 -0700 In-Reply-To: <1453444494-46900-1-git-send-email-aik@ozlabs.ru> References: <1453444494-46900-1-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2016-01-22 at 17:34 +1100, Alexey Kardashevskiy wrote: > Recent change 03a76b60 "vfio: Include No-IOMMU mode" disabled VFIO > on systems which do not implement iommu_ops for the PCI bus even > though > there is an VFIO IOMMU driver for it such as SPAPR TCE driver for > PPC64/powernv platform. > > This moves iommu_present() call under #ifdef CONFIG_VFIO_NOIOMMU as > it is done in the rest of the file to re-enable VFIO on powernv. > > Signed-off-by: Alexey Kardashevskiy > --- >  drivers/vfio/vfio.c | 5 ++++- >  1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index 82f25cc..3f8060e 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -343,7 +343,6 @@ static struct vfio_group > *vfio_create_group(struct iommu_group *iommu_group, >   atomic_set(&group->opened, 0); >   group->iommu_group = iommu_group; >   group->noiommu = !iommu_present; > - >   group->nb.notifier_call = vfio_iommu_group_notifier; >   >   /* > @@ -767,7 +766,11 @@ int vfio_add_group_dev(struct device *dev, >   >   group = vfio_group_get_from_iommu(iommu_group); >   if (!group) { > +#ifdef CONFIG_VFIO_NOIOMMU >   group = vfio_create_group(iommu_group, > iommu_present(dev->bus)); > +#else > + group = vfio_create_group(iommu_group, true); > +#endif >   if (IS_ERR(group)) { >   iommu_group_put(iommu_group); >   return PTR_ERR(group); A serious problem indeed, but this isn't the right solution.  I've copied you on a patch that I think fixes it.  Please verify.  Thanks, Alex