WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-ia64-devel

Re: [Xen-devel] [patch] make hypercall_preempt_check() a little more sen

To: Hollis Blanchard <hollisb@xxxxxxxxxx>
Subject: Re: [Xen-devel] [patch] make hypercall_preempt_check() a little more sensitive
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Fri, 31 Mar 2006 10:33:18 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 31 Mar 2006 09:34:23 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <200603301117.24152.hollisb@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <200603301117.24152.hollisb@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

On 30 Mar 2006, at 18:17, Hollis Blanchard wrote:

It would be an invasive patch to PowerPC Linux to modify the code that
disables the EE bit and additionally have it modify
vcpu_info->evtchn_upcall_mask, especially when that code is in assembly. Instead, we can have hypercall_preempt_check() also check MSR:EE directly.
IA64 may be able to use this facility as well, so I've CC'ed that list.

This patch fixes a problem where an event occurs, Linux calls back into Xen for e.g. console output, Xen sees that an event is pending and creates a
continuation and returns... loop forever.

I'd rather move event_pending() into asm/event.h and then you can monkey with it as you like. That'll also catch other uses of event_pending() where you probably also want the same extra check. I don't really want a proliferation of extra little functions called arch_xxx.

 -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>