From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754410Ab1BPUkV (ORCPT ); Wed, 16 Feb 2011 15:40:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64752 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754390Ab1BPUkS (ORCPT ); Wed, 16 Feb 2011 15:40:18 -0500 From: Alex Williamson Subject: [PATCH v2 0/2] intel-iommu: Fix domain_ids exhaustion To: dwmw2@infradead.org, iommu@lists.linux-foundation.org Cc: alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, ddutile@redhat.com, chrisw@redhat.com Date: Wed, 16 Feb 2011 13:39:41 -0700 Message-ID: <20110216203204.2979.13203.stgit@s20.home> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we unbind a device from a driver, we don't properly unlink the domain from the iommu, so we never free the domain id it was using. We're typically limited to something like 256 domain ids, so a loop of unbinding and rebinding a device can exhaust this pretty quickly. If we're assigning the device to a KVM guest, libvirt does exactly this each time the device is removed from the host driver or added back. When we do run out, we oops the kernel. Fix these. v2: We only want to call domain_exit() for domains automatically created via the dma ops path. VM and SI domains have their own life cycle and should not be destroyed here. With v1, if a device was unbound from pci-stub while assigned to a VM, the kernel would oops on the next call into iommu ops. BTW, should we even be removing the device from the domain in the VM domain case? Drivers and VM domains are (unfortunately) orthogonal concepts here with the way KVM is currently wired. Thanks, Alex --- Alex Williamson (2): intel-iommu: Fix get_domain_for_dev() error path intel-iommu: Unlink domain from iommu drivers/pci/intel-iommu.c | 15 +++++++++++++-- 1 files changed, 13 insertions(+), 2 deletions(-)