From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [Patch v2 0/9] Fix AMD IOMMU faults in kdump kernel Date: Fri, 27 Nov 2015 12:38:16 +0100 Message-ID: <20151127113816.GG24300@8bytes.org> References: <1446811851-20623-1-git-send-email-bhe@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1446811851-20623-1-git-send-email-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Baoquan He Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Fri, Nov 06, 2015 at 08:10:42PM +0800, Baoquan He wrote: > This is v2 draft patch set. It mainly functions as the following steps: > > 1. Checking if it's in kdump kernel and previously enabled > 2. If yes do below operatons: > a. Do not disable amd iommu and do not touch dev tables before coping old dev tables > b. Copy dev table from old kernel and set the old domain id in amd_iommu_pd_alloc_bitmap > c. Copy irq tables from old kernel > d. Copy command buffer and event buffer > e. Don't call update_domain() to set domain->pt_root to dev entries before device driver initialization. > f. Reset the pre-enabled status in case IOMMU_DMA_OPS of state_next(). > > Existed problems: "Existed" means here these problems are gone? > > 1. It always prints the following message whenever do a flush: > > "AMD-Vi: Completion-Wait loop timed out" > > 2. Maybe there's someing wrong with the old irq remapping handling, the hard disk can't be brought up > successfully. You can check the attached kdump kernel boot log with this patchset applied. The reason is most likely that you didn't re-initialize the command buffer before doing any flushes. The you see the above Completion-Wait loop timeouts. Joerg