From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Qemu-devel] [PATCH 2/3] memory: add API for creating ROM/device regions Date: Sat, 13 Aug 2011 20:05:25 -0700 Message-ID: <4E473B75.1050100@redhat.com> References: <1312822730-9577-1-git-send-email-avi@redhat.com> <1312822730-9577-3-git-send-email-avi@redhat.com> <4E452F28.5000902@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org To: Anthony Liguori Return-path: Received: from mx1.redhat.com ([209.132.183.28]:29238 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752819Ab1HNDFg (ORCPT ); Sat, 13 Aug 2011 23:05:36 -0400 In-Reply-To: <4E452F28.5000902@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: On 08/12/2011 06:48 AM, Anthony Liguori wrote: >> target_phys_addr_t offset_in_region; >> AddrRange addr; >> uint8_t dirty_log_mask; >> + bool readable; > @@ -125,6 +125,7 @@ struct FlatRange { > > In a follow up, it might be good to add a comment explaining that this > whole readable thing is not just an optimization, but a hard > requirement for KVM in order to be able to execute code from ROM. This has nothing to do with kvm (in fact, I think we cannot support it under kvm with current interfaces). It's there to support devices that sometimes act as RAM and sometimes as mmio. We could also do it with a container and playing with subregions. I tried it and it was pretty complicated. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.