From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [v7][PATCH 13/16] libxl: construct e820 map with RDM information for HVM guest Date: Mon, 13 Jul 2015 17:47:19 +0800 Message-ID: <55A38927.3030205@intel.com> References: <1436420047-25356-1-git-send-email-tiejun.chen@intel.com> <1436420047-25356-14-git-send-email-tiejun.chen@intel.com> <21918.47807.595901.751327@mariner.uk.xensource.com> <559F5AB0.5040506@intel.com> <1436519889.23508.185.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1436519889.23508.185.camel@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: Ian Campbell Cc: Wei Liu , Stefano Stabellini , Ian Jackson , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org > This approach looks like it should work, and I think given the point in > the release it would be acceptable for 4.6. > > However long term I think it might make sense to try and reuse one of > the existing libxl__arch hooks, i.e. > libxl__arch_domain_init_hw_description or > libxl__arch_domain_finalise_hw_description. On ARM these are to do with > setting the Device Tree Blob, which included the memory map, so it is > somewhat morally equivalent to configuring the e820 on x86, I think. > > Those hooks are only called from libxl__build_pv today, but calling them > from libxl__build_hvm seems like it would be good too. But seems this is raising some potential risks, isn't this? Although libxl__arch_domain_init_hw_description() and libxl__arch_domain_finalise_hw_description() are NOP to x86, they're really working on ARM side. So if we call them inside libxl__build_hvm(), any affects to ARM? I'm not very sure at this point unless anyone can validate this change on ARM, or you really ensure my concerns is unnecessary. > > In particular I think a call to > libxl__arch_domain_finalise_hw_description could be inserted just before > xc_hvm_build, which is similar to PV where it precedes > xc_dom_build_image, and is where you would want to setup the e820. > > libxl__arch_domain_init_hw_description I think would still be a NOP on > x86, but it should probably go either just after the call to > libxl__domain_firmware. > > Tiejun, would you be willing to commit to refactoring this and the > issues which Ian raised in response to #11 and #16 a subsequent clean up > series? I don't think it would even need to wait for the freeze to be > over to be posted (although it may need to wait to be applied). > Yes, I'd like to follow this once my concerns above can be eliminated. Thanks Tiejun