From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v3 3/4] pc & q35: Add new object pc-memory-layout. Date: Mon, 21 Apr 2014 08:27:44 -0400 Message-ID: <53550EC0.7070207@redhat.com> References: <1395705336-22528-1-git-send-email-dslutz@verizon.com> <1395705336-22528-4-git-send-email-dslutz@verizon.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1395705336-22528-4-git-send-email-dslutz@verizon.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: Don Slutz , xen-devel@lists.xensource.com, qemu-devel@nongnu.org, Stefano Stabellini Cc: Anthony Liguori , "Michael S. Tsirkin" List-Id: xen-devel@lists.xenproject.org Il 24/03/2014 19:55, Don Slutz ha scritto: > This new object has the property max-ram-below-4g. > > If you add enough PCI devices then all mmio for them will not fit > below 4G which may not be the layout the user wanted. This allows > you to increase the below 4G address space that PCI devices can use > (aka decrease ram below 4G) and therefore in more cases not have any > mmio that is above 4G. > > For example adding "-global pc-memory-layout.max-ram-below-4g=2G" to > the command line will limit the amount of ram that is below 4G to > 2G. Does Xen's firmware allow 64-bit BARs? I'm wondering why this is not a problem on KVM. Also, overloading -global like this isn't the best long term choice. We should get custom -machine properties in 2.1, we should use them. Paolo