Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751488AbaLQVhw (ORCPT ); Wed, 17 Dec 2014 16:37:52 -0500 Received: from g4t3427.houston.hp.com ([15.201.208.55]:56511 "EHLO g4t3427.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751084AbaLQVhu (ORCPT ); Wed, 17 Dec 2014 16:37:50 -0500 Date: Wed, 17 Dec 2014 14:37:47 -0700 From: Jerry Hoemann To: Joerg Roedel Cc: iommu@lists.linux-foundation.org, Alex Williamson , David Woodhouse , linux-kernel@vger.kernel.org, Joerg Roedel , stable@vger.kernel.org, Myron Stowe Subject: Re: [PATCH 1/2] iommu/vt-d: Fix dmar_domain leak in iommu_attach_device Message-ID: <20141217213747.GA11569@anatevka.fc.hp.com> Reply-To: Jerry.Hoemann@hp.com References: <1418813017-24888-1-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1418813017-24888-1-git-send-email-joro@8bytes.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 17, 2014 at 11:43:36AM +0100, Joerg Roedel wrote: > From: Joerg Roedel > > Since commit 1196c2f a domain is only destroyed in the > notifier path if it is hot-unplugged. This caused a > domain leakage in iommu_attach_device when a driver was > unbound from the device and bound to VFIO. In this case the > device is attached to a new domain and unlinked from the old > domain. At this point nothing points to the old domain > anymore and its memory is leaked. > Fix this by explicitly freeing the old domain in > iommu_attach_domain. > > Fixes: 1196c2f (iommu/vt-d: Fix dmar_domain leak in iommu_attach_device) > Cc: # v3.18 > Signed-off-by: Joerg Roedel > --- > drivers/iommu/intel-iommu.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 1232336..7610121 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -4428,6 +4428,10 @@ static int intel_iommu_attach_device(struct iommu_domain *domain, > domain_remove_one_dev_info(old_domain, dev); > else > domain_remove_dev_info(old_domain); > + > + if (!domain_type_is_vm_or_si(old_domain) && > + list_empty(&old_domain->devices)) > + domain_exit(old_domain); > } > } > > -- > 1.9.1 Joerg, Before applying this change on a 3.18-rc7 kernel layered on a RHEL 7.0 root disk, I was able to reproduce the memory leak that Alex reported when powering on/off a VM w/ a PCI device assigned to it. After applying this change, I don't see the memory leak anymore. Instrumentation shows the new code is being invoked during power on of the VM. Looks good. Thanks! Tested-by: Jerry Hoemann -- ---------------------------------------------------------------------------- Jerry Hoemann Software Engineer Hewlett-Packard 3404 E Harmony Rd. MS 36 phone: (970) 898-1022 Ft. Collins, CO 80528 FAX: (970) 898-0707 email: jerry.hoemann@hp.com ---------------------------------------------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/