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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 698C2CCF2D6 for ; Mon, 19 Oct 2026 09:20:30 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1454023.1667499 (Exim 4.92) (envelope-from ) id 1xIjXT-0007cM-Lz; Mon, 19 Oct 2026 09:20:15 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1454023.1667499; Mon, 19 Oct 2026 09:20:15 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1xIjXT-0007cF-J7; Mon, 19 Oct 2026 09:20:15 +0000 Received: by outflank-mailman (input) for mailman id 1454023; Mon, 19 Oct 2026 09:20:13 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1xIjXR-0007c9-Mk for xen-devel@lists.xenproject.org; Mon, 19 Oct 2026 09:20:13 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.98.2) (envelope-from ) id 1xIjXR-00000001qOD-2JBw; Mon, 19 Oct 2026 09:20:13 +0000 Received: from 224.pool85-54-217.dynamic.orange.es ([85.54.217.224] helo=localhost) by xenbits.xenproject.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1xIjXR-0000000AWJo-0b0K; Mon, 19 Oct 2026 09:20:13 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xenproject.org; s=20200302mail; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=DsMNP3oVCV+zJmeZgdlXyBn7vSmGn7A0GPS+igcZV1k=; b=sZcr+PAGzRIH73Xj9wBmFR8FFd ayo0qaaSdsGZBIDNkFrHbcalKRMuXr1j+BW81r2FqyTVb11C3O8OhzRxGAslUdg3HNMk+SXSKpL/K DHO2IFiwz//9u7K5AnrQYqnxE1eDLWycwzyWULLq4xrCDgydao0Lzk04O7RbQJpqpWCk=; Date: Mon, 19 Oct 2026 11:20:06 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Cc: "xen-devel@lists.xenproject.org" , Andrew Cooper , Teddy Astie , Marek Marczykowski Subject: Re: [PATCH 11/15] x86/PVH: try to map initrd directly into Dom0 Message-ID: References: <1b4c2bb4-118d-497c-8d7d-f3824fd61a73@suse.com> <78cd46cc-84ed-46df-96c9-26ce97ed0da0@suse.com> <764b7c0b-1a1e-4d0a-bded-28b5e9f9e703@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <764b7c0b-1a1e-4d0a-bded-28b5e9f9e703@suse.com> On Fri, Oct 16, 2026 at 11:12:34AM +0200, Jan Beulich wrote: > On 16.10.2026 11:01, Roger Pau Monné wrote: > > On Fri, Oct 16, 2026 at 10:58:09AM +0200, Jan Beulich wrote: > >> On 15.10.2026 19:41, Roger Pau Monné wrote: > >>> On Mon, Oct 12, 2026 at 10:25:11AM +0200, Jan Beulich wrote: > >>>> @@ -867,7 +1078,7 @@ static int __init pvh_load_kernel( > >>>> } > >>>> start_info.modlist_paddr = last_addr; > >>>> start_info.nr_modules = 1; > >>>> - last_addr += sizeof(mod); > >>>> + last_addr += sizeof(*mod); > >>>> } > >>>> > >>>> start_info.magic = XEN_HVM_START_MAGIC_VALUE; > >>> > >>> Isn't this still not properly ordered, as start_info address must > >>> strictly be below 4GB (as is passed in a CPU register with the CPU in > >>> 32bit mode), yet it is allocated last in pvh_load_kernel()? > >> > >> Well. For one, this is pre-existing. With the size of the region that > >> find_memory() needs to find greatly reduced when the initrd isn't > >> included there, there's about zero chance that it won't find a suitable > >> region below 4G. Once we have find_memory() go downwards from 4G, the > >> remaining little bit of a risk will also go away. > > > > Might be worth mentioning then, so it doesn't look like an oversight > > since you adjust the ACPI allocations. No strong opinion, just > > noticed it was left behind. > > I've added mention of this, but only in the remark of the patch. Really > pvh_setup_cpus() may want to check for no truncation? Or the parameter > type may want to change to uint32_t, with the no-truncation check then > living elsewhere? I think it would indeed be best if Xen checked for truncation. Whether it's in pvh_setup_cpus() or somewhere else I don't have a strong opinion. Thanks, Roger.