From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v14 00/20] Introduce PVH domU support Date: Fri, 8 Nov 2013 15:53:24 +0000 Message-ID: <527D08F4.8030609@eu.citrix.com> References: <1383567306-6636-1-git-send-email-george.dunlap@eu.citrix.com> <20131104165905.GA6979@phenom.dumpdata.com> <5277D7FB.30208@eu.citrix.com> <20131104173452.GB45309@deinos.phlegethon.org> <527D0623.4000504@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <527D0623.4000504@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Tim Deegan Cc: Keir Fraser , Ian Campbell , Jan Beulich , xen-devel@lists.xen.org, Ian Jackson List-Id: xen-devel@lists.xenproject.org On 08/11/13 15:41, George Dunlap wrote: > On 04/11/13 17:34, Tim Deegan wrote: >> At 17:23 +0000 on 04 Nov (1383582187), George Dunlap wrote: >>> On 04/11/13 16:59, Konrad Rzeszutek Wilk wrote: >>>>> This also means no support for "legacy" forced invalid ops -- only >>>>> native >>>>> cpuid is supported in this series. >>>> OK. >>> (FWIW, support for legacy forced invalid ops was requested by Tim.) >> I was worried about existing PV kernel code that used the fake-CPUID, >> which would break if the 'core' kernel code went from PV to PVH. But >> I guess I could be convinced that such kernel code is buggy? Really, >> the high-order bit was consistency. The version I commented on >> supported them for user-space but not for kernel, which seemed like >> risking trouble for no benefit. > > Oh right -- I think Mukesh we do need to support forced invalid ops > for user space so that we can use the same xen tools binaries on PV > and PVH kernels. > > Hmm, Mukesh / Konrad, what tools are you actually thinking about > here? Are these Oracle-specific tools? I can't seem to find > XEN_CPUID or XEN_EMULATE_PREFIX anywhere in the tools/ directory of > the xen repo... It's misc/xen-detect.c, for the curious (which helpfully does not use the macros above). Handling forced invalid ops it is, then. I think it would make sense to handle them in the plain HVM case as well -- that way xen-detect could also work inside of PVHVM domains. -George