From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Lalancette Subject: Re: 32-on-64 support in xen-unstable? Date: Mon, 06 Jul 2009 16:44:51 +0200 Message-ID: <4A520DE3.8010207@redhat.com> References: <4A5207B1.3030808@redhat.com> <4A5228600200007800008FC5@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4A5228600200007800008FC5@vpn.id2.novell.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: Jan Beulich Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Jan Beulich wrote: >>>> Chris Lalancette 06.07.09 16:18 >>> >> Hello, >> I've been browsing through the preemptible pagetable stuff, and ran across >> a piece of code that I don't understand or is buggy. Looking at >> arch/x86/mm.c:new_guest_cr3(), we have this code for 32-on-64 support: > > You probably overlooked the == 0 et the end of the expression: > >> if ( is_pv_32on64_domain(d) ) >> { >> okay = paging_mode_refcounts(d) >> ? 0 /* Old code was broken, but what should it be? */ >> : mod_l4_entry( >> __va(pagetable_get_paddr(curr->arch.guest_table)), >> l4e_from_pfn( >> mfn, >> (_PAGE_PRESENT|_PAGE_RW|_PAGE_USER|_PAGE_ACCESSED)), >> pagetable_get_pfn(curr->arch.guest_table), 0, 0, curr) == 0; > ^^^^ > > Which basically is equivalent to what you were trying to suggest. D'oh! Of course. I did overlook that, thanks for pointing it out. -- Chris Lalancette