From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43809) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YW76k-0002oy-JN for qemu-devel@nongnu.org; Thu, 12 Mar 2015 13:41:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YW76h-0004h0-U1 for qemu-devel@nongnu.org; Thu, 12 Mar 2015 13:41:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54943) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YW76h-0004gu-NZ for qemu-devel@nongnu.org; Thu, 12 Mar 2015 13:41:15 -0400 Message-ID: <5501CFB8.6090801@redhat.com> Date: Thu, 12 Mar 2015 13:41:12 -0400 From: John Snow MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] ahci: map memory via device's address space instead of address_space_memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jordan Hargrave , qemu-devel@nongnu.org On 02/26/2015 12:13 AM, Jordan Hargrave wrote: > Referencing this old thread: > https://lists.nongnu.org/archive/html/qemu-devel/2014-07/msg00606.html > > I've run into an issue recently with testing q35 DMAR/intel iommu with > ahci driver. My ahci driver writes the upper-32 bits (PORT_FIS_ADDR_HI) > first then the lower 32-bits (PORT_FIS_ADDR). > > The contents of PORT_FIS_ADDR therefore are stale when the > PORT_FIS_ADDR_HI write calls map_page(). DMAR translation fails at this > point as the old stale address (from SEABIOS initialization) is not in > the DMAR page table. > Hi: I posted a fix, but do you mind elaborating on what the failure actually looked like? Did QEMU abort, did the guest crash, etc? What exact behavior did you observe? Do you have a command line to share with us? --js