From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: Re: HYBRID: gnttab_map() to map shared frames.. Date: Thu, 20 Oct 2011 11:39:12 +0100 Message-ID: <20111020103912.GF49983@ocelot.phlegethon.org> References: <20111013181853.15381ef5@mantra.us.oracle.com> <20111017191810.28876947@mantra.us.oracle.com> <1318925582.16132.31.camel@zakaz.uk.xensource.com> <20111018121727.27a3f03c@mantra.us.oracle.com> <1319013573.3385.60.camel@zakaz.uk.xensource.com> <20111019192918.627bfe70@mantra.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <20111019192918.627bfe70@mantra.us.oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Mukesh Rathor Cc: Keir Fraser , "Xen-devel@lists.xensource.com" , Ian Campbell , Jeremy Fitzhardinge List-Id: xen-devel@lists.xenproject.org At 19:29 -0700 on 19 Oct (1319052558), Mukesh Rathor wrote: > > What about using PFNs from right at the top, i.e. right up near > > 0xffffffff? I don't think there's any particular reason these special > > PFNs need to be contiguous with the "regular" ones. This would limit > > the total amount of RAM you could give a hybrid guest, but not by > > much. > > Yeah, I dinkered around a bit with e820 and realized it would be > migration headache, so just decided to do this. I allocate pfn's near > 0xffffffff and map it. Things are fine, I see all page table entries > just fine, the entry is put into the p2m also via ept_set_entry, but > for some reason it's taking fault on accessing shared[0] with error > code 0xb that doesn't make sense. Even the mfn in xen is writable > page. > > PGD 77895067 PUD 77896067 PMD 77897067 PTE 80000ffffffdf063 0xB means you've got a reserved bit set. Is 0xfff_fffdf000 above the number of supported addressing bits on your CPU, by any chance? Cheers, Tim