From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40228) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e6Z8v-0006hB-T7 for qemu-devel@nongnu.org; Mon, 23 Oct 2017 05:35:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e6Z8s-0002Rp-QE for qemu-devel@nongnu.org; Mon, 23 Oct 2017 05:35:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52998) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e6Z8s-0002RW-Jt for qemu-devel@nongnu.org; Mon, 23 Oct 2017 05:35:30 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6D0D0882FF for ; Mon, 23 Oct 2017 09:35:29 +0000 (UTC) References: <20171018095807.101406-1-marcel@redhat.com> <69cefa98-5681-5b12-719c-e13fcba969c4@redhat.com> <9d4b1fa8-e670-556b-278d-4993ad41b512@redhat.com> <1508418225.18146.1.camel@redhat.com> <1508482525.18146.6.camel@redhat.com> <1508737557.16488.1.camel@redhat.com> <083108b4-6300-6302-d8c8-108fc6ae07fb@redhat.com> <1508750176.16488.6.camel@redhat.com> From: Marcel Apfelbaum Message-ID: Date: Mon, 23 Oct 2017 12:35:17 +0300 MIME-Version: 1.0 In-Reply-To: <1508750176.16488.6.camel@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] hw/pci-host: Fix x86 Host Bridges 64bit PCI hole List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann , Laszlo Ersek , qemu-devel@nongnu.org Cc: mst@redhat.com, pbonzini@redhat.com, ehabkost@redhat.com, Igor Mammedov , "Dr. David Alan Gilbert" On 23/10/2017 12:16, Gerd Hoffmann wrote: > On Mon, 2017-10-23 at 11:46 +0300, Marcel Apfelbaum wrote: >> On 23/10/2017 8:45, Gerd Hoffmann wrote: >>> =C2=A0=C2=A0=C2=A0Hi, >>> >>>> The guest will still run with 40 bits physical! >>>> (judging the code anyway, I hope I am wrong) >>>> >>>> Then, the stakes are not so big, the Guest kernel will disregard >>>> the 64bit hole since is not CPU addressable and go on. >>> >>> But then there is no working 64bit hole for hotplug ... >>> >> >> Hosts with old CPUs are not fit for modern PCIe devices >> having large BARs anyway, no 64bit hole in this case would >> be OK, I think. >=20 > Well, my workstation which has only 39 bits physical is kaby lake. > If you classify this as "old cpu", what is a new cpu then? >=20 Maybe the term "old" was not the best ..., server CPU intended for bigger hosts with a lot of RAM? Anyway, having a 32G PCI hotplug window for Q35 should be OK, for now. Thanks, Marcel > cheers, > Gerd >=20