Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759060Ab0DBBjh (ORCPT ); Thu, 1 Apr 2010 21:39:37 -0400 Received: from sous-sol.org ([216.99.217.87]:37994 "EHLO sequoia.sous-sol.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757780Ab0DBBjd (ORCPT ); Thu, 1 Apr 2010 21:39:33 -0400 Date: Thu, 1 Apr 2010 18:38:27 -0700 From: Chris Wright To: Neil Horman Cc: Chris Wright , Joerg Roedel , Neil Horman , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, hbabu@us.ibm.com, iommu@lists.linux-foundation.org, "Eric W. Biederman" , Vivek Goyal Subject: Re: [PATCH 1/2] x86/amd-iommu: enable iommu before attaching devices Message-ID: <20100402013827.GA29241@sequoia.sous-sol.org> References: <20100331202745.GE13406@hmsreliant.think-freely.org> <20100401142902.GF24846@8bytes.org> <20100401144736.GA14069@shamino.rdu.redhat.com> <20100401155643.GG24846@8bytes.org> <20100401171149.GH13603@shamino.rdu.redhat.com> <20100401201433.GK24846@8bytes.org> <20100402000012.GA8930@hmsreliant.think-freely.org> <20100402003034.GX29241@sequoia.sous-sol.org> <20100402012353.GY29241@sequoia.sous-sol.org> <20100402013513.GA2435@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100402013513.GA2435@localhost.localdomain> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1354 Lines: 28 * Neil Horman (nhorman@redhat.com) wrote: > On Thu, Apr 01, 2010 at 06:23:53PM -0700, Chris Wright wrote: > > Hit another kdump problem as reported by Neil Horman. When initializaing > > the IOMMU, we attach devices to their domains before the IOMMU is > > fully (re)initialized. Attaching a device will issue some important > > invalidations. In the context of the newly kexec'd kdump kernel, the > > IOMMU may have stale cached data from the original kernel. Because we > > do the attach too early, the invalidation commands are placed in the new > > command buffer before the IOMMU is updated w/ that buffer. This leaves > > the stale entries in the kdump context and can renders device unusable. > > Simply enable the IOMMU before we do the attach. > > > > Cc: Neil Horman > > Cc: Vivek Goyal > > Signed-off-by: Chris Wright > > I'll test this out this weekend, thanks Chris! Great, thanks! I tested w/ both default and iommu=pt. Both worked, didn't spot any regressions. But additional testing is very welcome. thanks, -chris -- 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/