From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37488) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGotq-0004or-G9 for qemu-devel@nongnu.org; Thu, 29 Jan 2015 08:12:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YGotn-0000do-8o for qemu-devel@nongnu.org; Thu, 29 Jan 2015 08:12:46 -0500 Message-ID: <54CA31C9.2080406@suse.de> Date: Thu, 29 Jan 2015 14:12:41 +0100 From: Alexander Graf MIME-Version: 1.0 References: <1421202819-19860-1-git-send-email-david@gibson.dropbear.id.au> In-Reply-To: <1421202819-19860-1-git-send-email-david@gibson.dropbear.id.au> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] pseries: Limit PCI host bridge "index" value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson , aik@ozlabs.ru, mdroth@us.ibm.com Cc: pbonzini@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org On 14.01.15 03:33, David Gibson wrote: > pseries guests can have large numbers of PCI host bridges. To avoid the > user having to specify a number of different configuration values for every > one, the device supports an "index" property which is a shorthand setting > the various window and configuration addresses from a predefined sensible > set. > > There are some problems with the details at present: > * The "index" propery is signed, but negative values will create PCI > windows below where we expect, potentially colliding with other devices > * No limit is imposed on the "index" property and large values can > translate to extremely large window addresses. With PCI passthrough in > particular this can mean we exceed various mapping and physical address > limits causing the guest host bridge to not work in strange ways. > > This patch addresses this, by making "index" unsigned, and imposing a > limit. Currently the limit allows indices from 0..255 which is probably > enough host bridges for the time being. It's fairly easy to extend if > we discover we need more. > > Signed-off-by: David Gibson Thanks, applied to ppc-next. Alex