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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21CE7C77B7A for ; Wed, 7 Jun 2023 13:13:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240096AbjFGNNI (ORCPT ); Wed, 7 Jun 2023 09:13:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235792AbjFGNNC (ORCPT ); Wed, 7 Jun 2023 09:13:02 -0400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0F0795 for ; Wed, 7 Jun 2023 06:13:01 -0700 (PDT) Received: by verein.lst.de (Postfix, from userid 2407) id 33B3F6732D; Wed, 7 Jun 2023 15:12:58 +0200 (CEST) Date: Wed, 7 Jun 2023 15:12:57 +0200 From: Christoph Hellwig To: Juergen Gross Cc: Marek =?iso-8859-1?Q?Marczykowski-G=F3recki?= , Christoph Hellwig , Stefano Stabellini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Ben Skeggs , Karol Herbst , Lyude Paul , xen-devel@lists.xenproject.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, nouveau@lists.freedesktop.org Subject: Re: [PATCH 2/4] x86: always initialize xen-swiotlb when xen-pcifront is enabling Message-ID: <20230607131257.GB19206@lst.de> References: <20230518134253.909623-1-hch@lst.de> <20230518134253.909623-3-hch@lst.de> <20230519040405.GA10818@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 22, 2023 at 10:37:09AM +0200, Juergen Gross wrote: > In normal cases PCI passthrough in PV guests requires to start the guest > with e820_host=1. So it should be rather easy to limit allocating the > 64MB in PV guests to the cases where the memory map has non-RAM regions > especially in the first 1MB of the memory. > > This will cover even hotplug cases. The only case not covered would be a > guest started with e820_host=1 even if no PCI passthrough was planned. > But this should be rather rare (at least I hope so). So is this an ACK for the patch and can we go ahead with it? (I'd still like to merge swiotlb-xen into swiotlb eventually, but it's probably not going to happen this merge window)