From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smarthost01a.ixn.mail.zen.net.uk (smarthost01a.ixn.mail.zen.net.uk [212.23.1.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86CEC34EEF3 for ; Fri, 16 Jan 2026 09:27:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.23.1.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768555640; cv=none; b=QCcBNSHV3XNK0+utV6cbNUE0LJDE13aMCpFOYITvtOHMaHeiPKEDxj8oBuvBJ/NyXp2O2foXDpQRuWygMQj5m0JUx1FdolkZBUG9JYblFB/ptJYBBadisxrGqv+mF0l4eIlU1VXilTLKc+UU88UNltLGGL+UO8f5s3wuv0wEsx8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768555640; c=relaxed/simple; bh=TYEqQibElTQD5/7EpZfQn/6Oe6lk5zW9WRj9CgmoT4k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jQXEhvsMg1K/t8xqeQQbqXvhVzkY7cCUXP07FXlEbly/mpGB90ZGolHDQhlusJxaM/rkL9L89SKOQVpFkxlHI3Oq9vOl4RLoO1mpnpPuZvjZy4e0CRqUleAcHBQsBw4npOwWQFVQvWryRlJLCCJKC+51Y0NBkbVz/oHW+zlhDVs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=dingwall.me.uk; spf=pass smtp.mailfrom=dingwall.me.uk; arc=none smtp.client-ip=212.23.1.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=dingwall.me.uk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dingwall.me.uk Received: from [217.155.64.189] (helo=mail0.xen.dingwall.me.uk) by smarthost01a.ixn.mail.zen.net.uk with esmtpsa (TLS1.0) tls TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (Exim 4.95) (envelope-from ) id 1vgg6u-008u96-KR; Fri, 16 Jan 2026 09:27:16 +0000 Received: from localhost (localhost [IPv6:::1]) by mail0.xen.dingwall.me.uk (Postfix) with ESMTP id 3520CDEF44B; Fri, 16 Jan 2026 09:27:16 +0000 (GMT) X-Virus-Scanned: Debian amavis at dingwall.me.uk Received: from mail0.xen.dingwall.me.uk ([IPv6:::1]) by localhost (mail0.xen.dingwall.me.uk [IPv6:::1]) (amavis, port 10024) with ESMTP id bxQ01hF6uZu1; Fri, 16 Jan 2026 09:27:16 +0000 (GMT) Received: from ghoul.dingwall.me.uk (ghoul.dingwall.me.uk [IPv6:2a02:8010:698e:302::c0a8:1c8]) by dingwall.me.uk (Postfix) with ESMTP id 13793DEF448; Fri, 16 Jan 2026 09:27:16 +0000 (GMT) Received: by ghoul.dingwall.me.uk (Postfix, from userid 1000) id 09F98B98; Fri, 16 Jan 2026 09:27:15 +0000 (GMT) Date: Fri, 16 Jan 2026 09:27:15 +0000 From: James Dingwall To: Roger Pau =?iso-8859-1?Q?Monn=E9?= Cc: linux-kernel@vger.kernel.org Subject: Re: xen pci passthrough stops working after xen/x86: fix initial memory balloon target Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Originating-smarthost01a-IP: [217.155.64.189] Feedback-ID: 217.155.64.189 On Thu, Jan 15, 2026 at 06:55:15PM +0100, Roger Pau Monné wrote: > On Thu, Jan 15, 2026 at 02:50:12PM +0000, James Dingwall wrote: > > On Thu, Jan 15, 2026 at 01:03:49PM +0100, Roger Pau Monné wrote: > > > On Thu, Jan 15, 2026 at 11:23:37AM +0000, James Dingwall wrote: > > > > Hi, > > > > > > > > We have encountered a regression with pci passthrough since the > > > > Ubuntu 6.8.0-91.92 which included this commit: > > > > > > Hello, > > > > > > Thanks for the report. Could you also send me your kernel Kconfig, to > > > see which combination of options are you using? > > > > > > Can you confirm that the config used to build the non-working kernel > also has CONFIG_XEN_UNPOPULATED_ALLOC=y? The config is the same for both builds and CONFIG_XEN_UNPOPULATED_ALLOC=y is always set. > Can you also provide the output of `cat /proc/iomem` for both the > working and non-working kernels? non-working Ubuntu-6.8.0-100.100: 00000000-00000fff : Reserved 00001000-0009ffff : System RAM 000a0000-000fffff : Reserved 000f0000-000fffff : System ROM 00100000-2007ffff : System RAM 01000000-025fffff : Kernel code 02600000-033bcfff : Kernel rodata 03400000-0385613f : Kernel data 03d54000-041fffff : Kernel bss 20081000-73b57fff : Unusable memory 76c58000-76d76fff : ACPI Tables 76d77000-76ea0fff : ACPI Non-volatile Storage 77fff000-77ffffff : Unusable memory 80000000-87ffffff : System RAM 88000000-8fffffff : Xen scratch 100000000-103f7ffff : System RAM 4000200000-400021ffff : 0000:01:00.0 4000220000-400023ffff : 0000:01:00.0 4000240000-400025ffff : 0000:01:00.1 4000260000-400027ffff : 0000:01:00.1 working Ubuntu-6.8.0-100.100: 00000000-00000fff : Reserved 00001000-0009ffff : System RAM 000a0000-000fffff : Reserved 000f0000-000fffff : System ROM 00100000-2007ffff : System RAM 01000000-025fffff : Kernel code 02600000-033bcfff : Kernel rodata 03400000-0385613f : Kernel data 03d54000-041fffff : Kernel bss 20081000-73b57fff : Unusable memory 76c58000-76d76fff : ACPI Tables 76d77000-76ea0fff : ACPI Non-volatile Storage 77fff000-77ffffff : Unusable memory 81100000-811fffff : 0000:01:00.1 81100000-811fffff : igb 81200000-812fffff : 0000:01:00.0 81200000-812fffff : igb 81300000-8137ffff : 0000:01:00.1 81380000-813fffff : 0000:01:00.0 81400000-81403fff : 0000:01:00.1 81400000-81403fff : igb 81404000-81407fff : 0000:01:00.0 81404000-81407fff : igb 81500000-815fffff : 0000:03:00.0 81600000-816fffff : 0000:03:00.0 81600000-816fffff : igc 81700000-81703fff : 0000:03:00.0 81700000-81703fff : igc 88000000-8fffffff : Xen scratch 100000000-103f7ffff : System RAM 4000200000-400021ffff : 0000:01:00.0 4000220000-400023ffff : 0000:01:00.0 4000240000-400025ffff : 0000:01:00.1 4000260000-400027ffff : 0000:01:00.1 Just for completeness the working build also reverts "xen/x86: fix initial memory balloon target" because of a conflict in drivers/xen/balloon.c. Thanks, James