From mboxrd@z Thu Jan 1 00:00:00 1970 From: Izik Eidus Subject: Re: [PATCH] kvm-userspace: set pci mem to start at 0xc100000 and vesa to 0xc000000 Date: Sat, 17 Jan 2009 03:23:14 +0200 Message-ID: <49713302.1010705@redhat.com> References: <1231637150-12127-1-git-send-email-ieidus@redhat.com> <1231637150-12127-2-git-send-email-ieidus@redhat.com> <20090117005748.GA32499@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, avi@redhat.com To: Chris Wright Return-path: Received: from mx2.redhat.com ([66.187.237.31]:46381 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482AbZAQIRk (ORCPT ); Sat, 17 Jan 2009 03:17:40 -0500 In-Reply-To: <20090117005748.GA32499@sequoia.sous-sol.org> Sender: kvm-owner@vger.kernel.org List-ID: Chris Wright wrote: > * Izik Eidus (ieidus@redhat.com) wrote: > >> This patch make the pci mem region larger (1 giga now). >> this is needed for pci devices that require large amount of memory >> such as video cards. >> >> for pea guests this patch is not an issue beacuse the guest OS will map >> the rest of the ram after 0x100000000..., >> for 32bits that arent pea, it mean the maximum memory that would be >> avaible now is 3giga. >> > > Seems a little heavy handed. > > a) Given the size...code could be cleaned up so that a simple constant > change doesn't need to touch so much code. > Yea it probably can... > b) It is brute force. I'm not sure it really matters all that much to > limit a 32-bit (non-PAE) guest to 3G, but it's a little extreme for the > cases that don't care about the large hole. > > Is there anyway to make it dynamic based on the requirements of the > devices that are part of the launched VM? > There is (you need to transfer data to the bios but it is possible...), the thing is - there was concern that it will make windows crazy if you keep changing the devices physical mapping Avi what do you think? > thanks, > -chris >