From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: (v2) Design proposal for RMRR fix Date: Mon, 19 Jan 2015 11:08:03 +0000 Message-ID: <1421665683.10440.45.camel@citrix.com> References: <54B515E6020000780005444A@mail.emea.novell.com> <54B54D48020000780005473E@mail.emea.novell.com> <54B540AA.1010905@eu.citrix.com> <54B63E250200007800054A36@mail.emea.novell.com> <54B651EE0200007800054ADD@mail.emea.novell.com> <54B65AB4.5060504@eu.citrix.com> <54B68C180200007800054E84@mail.emea.novell.com> <54B67F32.8050902@eu.citrix.com> <54B68FA10200007800054F01@mail.emea.novell.com> <54B6B578.60106@eu.citrix.com> <54B78A5A02000078000552C2@mail.emea.novell.com> <54BCDA93.70106@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54BCDA93.70106@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: George Dunlap Cc: "Tian, Kevin" , "wei.liu2@citrix.com" , "stefano.stabellini@eu.citrix.com" , "ian.jackson@eu.citrix.com" , "tim@xen.org" , "xen-devel@lists.xen.org" , Jan Beulich , "Zhang, Yang Z" , "Chen, Tiejun" List-Id: xen-devel@lists.xenproject.org On Mon, 2015-01-19 at 10:21 +0000, George Dunlap wrote: > On 01/18/2015 08:58 AM, Tian, Kevin wrote: > >> From: George Dunlap > >> Sent: Thursday, January 15, 2015 7:45 PM > >> > >>> > >>> If above high level flow can be agreed, then we can move forward to > >>> discuss next level detail e.g. how to pass the rmrr list cross different > >>> components. :-) > >> > >> I think we're definitely ready to move on. There are a bunch of tiny > >> details we could discuss, but those are mostly minor changes that can > >> be tweaked when the patches are submitted. > >> > > > > Thanks for all the good discussions in the thread, and good we have > > consensus to move forward now. > > > > still one open to hear suggestion though, regarding to how we want > > to pass the reserved regions to domain builder and hvmloader (for Xen > > we will extend related assignment hypercall to include per device override). > > > > one simple solution is to extend xc_hvm_build_args and hvm_info_table > > to include specified regions, with the limitation on defining a fixed > > number (possibly use E820_MAX as a reasonable assumption) > > > > another option is to place the information in xenstore which is more > > flexible. However domain builder doesn't use xenstore right now (suppose > > extending use xenstore is not complex?) > > I *think* the last time I asked such a question, the answer was that > allowing the domain builder to access xenstore would introduce a > cyclical dependency. But I can't remember the details now (and I may h > ave it wrong). IIRC libxenstore depends on libxenctrl, so having libxenctrl depend on libxenstore would be problematic. (There has been talk recently of refactoring libxenctrl into multiple more single-minded libraries, which might help with this so of thing). I don't think xenstore is particularly the right answer here though, either hvm_info (or a table referenced from it) or, since Jan doesn't like that approach, a hypercall as he suggests would work. Ian.