From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38580) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHAyH-0002l7-Dy for qemu-devel@nongnu.org; Thu, 07 Jan 2016 08:51:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aHAyE-0005fF-6D for qemu-devel@nongnu.org; Thu, 07 Jan 2016 08:51:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48276) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHAyE-0005fA-1T for qemu-devel@nongnu.org; Thu, 07 Jan 2016 08:51:18 -0500 Date: Thu, 7 Jan 2016 14:51:13 +0100 From: Igor Mammedov Message-ID: <20160107145113.7b459368@nial.brq.redhat.com> In-Reply-To: <568AD35B.9010400@redhat.com> References: <1449040860-19040-1-git-send-email-guangrong.xiao@linux.intel.com> <5680A0C8.6040505@linux.intel.com> <20151228141917-mutt-send-email-mst@redhat.com> <20151230165554.4d15e5a4@nial.brq.redhat.com> <20151230213740-mutt-send-email-mst@redhat.com> <568AD35B.9010400@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] How to reserve guest physical region for ACPI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laszlo Ersek Cc: Xiao Guangrong , ehabkost@redhat.com, kvm@vger.kernel.org, "Michael S. Tsirkin" , gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net On Mon, 4 Jan 2016 21:17:31 +0100 Laszlo Ersek wrote: > Michael CC'd me on the grandparent of the email below. I'll try to add > my thoughts in a single go, with regard to OVMF. > > On 12/30/15 20:52, Michael S. Tsirkin wrote: > > On Wed, Dec 30, 2015 at 04:55:54PM +0100, Igor Mammedov wrote: > >> On Mon, 28 Dec 2015 14:50:15 +0200 > >> "Michael S. Tsirkin" wrote: > >> > >>> On Mon, Dec 28, 2015 at 10:39:04AM +0800, Xiao Guangrong wrote: > >>>> > >>>> Hi Michael, Paolo, > >>>> > >>>> Now it is the time to return to the challenge that how to reserve guest > >>>> physical region internally used by ACPI. > >>>> > >>>> Igor suggested that: > >>>> | An alternative place to allocate reserve from could be high memory. > >>>> | For pc we have "reserved-memory-end" which currently makes sure > >>>> | that hotpluggable memory range isn't used by firmware > >>>> (https://lists.nongnu.org/archive/html/qemu-devel/2015-11/msg00926.html) > > OVMF has no support for the "reserved-memory-end" fw_cfg file. The > reason is that nobody wrote that patch, nor asked for the patch to be > written. (Not implying that just requesting the patch would be > sufficient for the patch to be written.) Hijacking this part of thread to check if OVMF would work with memory-hotplug and if it needs "reserved-memory-end" support at all. How OVMF determines which GPA ranges to use for initializing PCI BARs at boot time, more specifically 64-bit BARs.