From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09609C433DF for ; Wed, 17 Jun 2020 10:13:33 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C93E6208B3 for ; Wed, 17 Jun 2020 10:13:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dSp01IFO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C93E6208B3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49006 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jlV4V-0007zE-Vq for qemu-devel@archiver.kernel.org; Wed, 17 Jun 2020 06:13:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51140) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jlV3k-0007Xa-MG for qemu-devel@nongnu.org; Wed, 17 Jun 2020 06:12:44 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:28206 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jlV3h-0005GJ-Ep for qemu-devel@nongnu.org; Wed, 17 Jun 2020 06:12:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592388760; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8PH+aBFQhaaxJuiZ/GoEzxDAK48PB7lLMQZV7XnC9ms=; b=dSp01IFOh4/6BVLhB9yRtl53xI41L8tZyB4+oiwUUe1XzjwqMxB2FGjLg758ltpiXrbebC BzSfc9+xWPINBXI9Lx5RRNBuo/k1OUKWpj1Fn8fqX7FHZ6tYrvWAK4lWM0Md5Lqmr1Y08r mRzuqX40Godah++G9Kg7/+BGshUiVfA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-179-koRDVVH6Poi-6gwFoOF3YA-1; Wed, 17 Jun 2020 06:12:36 -0400 X-MC-Unique: koRDVVH6Poi-6gwFoOF3YA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 030368C3201; Wed, 17 Jun 2020 10:12:35 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-112-67.ams2.redhat.com [10.36.112.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 76FBB5D9D3; Wed, 17 Jun 2020 10:12:34 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 54F9116E16; Wed, 17 Jun 2020 12:12:33 +0200 (CEST) Date: Wed, 17 Jun 2020 12:12:33 +0200 From: Gerd Hoffmann To: Christophe de Dinechin Subject: Re: ovmf / PCI passthrough impaired due to very limiting PCI64 aperture Message-ID: <20200617101233.feo4vvdsgdpc4n3f@sirius.home.kraxel.org> References: <99779e9c-f05f-501b-b4be-ff719f140a88@canonical.com> <20200616165043.24y2cp53axk7uggy@sirius.home.kraxel.org> <97D6912A-C840-4723-A32F-7B05FF827EB8@redhat.com> MIME-Version: 1.0 In-Reply-To: <97D6912A-C840-4723-A32F-7B05FF827EB8@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.81; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/17 01:42:42 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pedro.principeza@canonical.com, ehabkost@redhat.com, dann.frazier@canonical.com, "Guilherme G. Piccoli" , qemu-devel@nongnu.org, christian.ehrhardt@canonical.com, dgilbert@redhat.com, lersek@redhat.com, fw@gpiccoli.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jun 17, 2020 at 10:16:55AM +0200, Christophe de Dinechin wrote: > > > > Le 16 Jun 2020 à 18:50, Gerd Hoffmann a écrit : > > > > Hi, > > > >> (a) We could rely in the guest physbits to calculate the PCI64 aperture. > > > > I'd love to do that. Move the 64-bit I/O window as high as possible and > > use -- say -- 25% of the physical address space for it. > > > > Problem is we can't. > > Is the only reason unreliable guest physbits? Yes. > > If we can somehow make a *trustable* physbits value available to the > > guest, then yes, we can go that route. But the guest physbits we have > > today unfortunately don't cut it. > > What is the rationale for ever allowing guest physbits > host physbits? I can't think of a good reason. So probably simply historical reasons and the fact that this isn't a problem with tcg. take care, Gerd Hoffmann