From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [semi-urgent Xen CS question] Re: git commit 9fd67b4ed0714ab718f1f9bd14c344af336a6df7 (x86-64: Give vvars their own page) breaks Xen PV guests (64-bit). Date: Wed, 27 Jul 2011 08:40:46 -0700 Message-ID: <4E30317E.30706@goop.org> References: <1093cd3a-acfe-49ab-b410-9fb49b139816@email.android.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Andrew Lutomirski Cc: Keir Fraser , xen-devel@lists.xensource.com, Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org On 07/26/2011 07:17 PM, Andrew Lutomirski wrote: > On Tue, Jul 26, 2011 at 7:37 PM, j.fitz.inge@gmail.com wrote: >> The correct fix is to just look at the cpl in cs and ignore the rest of the >> selector. > No. All three of these code paths are trap handlers that are trying > to distinguish between 64-bit and 32-bit segments. The CPL is 3 in > either case. Oh, hm. > It looks like the reason I didn't find the code that it references > TRAP_syscall not VCGF_in_syscall. Yay for grep-unfriendly code. > > Barring a better idea, I'll implement a new paravirt op. > Ugh. I'd really like to avoid that. J