From mboxrd@z Thu Jan 1 00:00:00 1970 From: Diego Ongaro Subject: Re: [PATCH] gnttab_setup_table error case Date: Thu, 31 Jul 2008 14:12:55 +0100 Message-ID: <4891BA57.5010806@citrix.com> References: <489069F3.7070200@citrix.com> <20080731020828.GA5842@ub-qhe2> <20080731085858.GE5427@implementation> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20080731085858.GE5427@implementation> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Samuel Thibault , Qing He Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Samuel Thibault wrote: > Qing He, le Thu 31 Jul 2008 10:08:28 +0800, a =E9crit : >> On Wed, 2008-07-30 at 14:17 +0100, Diego Ongaro wrote: >>> gnttab_setup_table should set an error status code if the gmfn it get= s >>> for a grant table page is invalid. >>> >>> I ran into this issue when I tried to set up the grant table during h= vm >>> domain creation, and it caused a BUG_ON later down the line. With thi= s >>> patch, the hypercall will gracefully fail instead. >> Do you use 32bit guest on top of 64bit hypervisor? >=20 > No, just 64/64. Well, no, it was 32 on 64 :) >> Just curious, but why we want to call setup_table in HVM in the first >> place. Since HVM has its isolated address space, it will always fail. >=20 > That was for his personal project. The call was made from dom0. The > problem is that it triggers a BUG_ON, which we do not really want to > happen :) Keir's xen-unstable.hg cs 18177:9ee2e41a68a1 simply removed the problematic BUG_ON, so at least userspace can now handle the error. -Diego