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] Call hypercall straightly from user space

To: "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] Call hypercall straightly from user space
From: "Xu, Anthony" <anthony.xu@xxxxxxxxx>
Date: Sun, 31 Dec 2006 12:30:21 +0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, xen-ia64-devel <xen-ia64-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Sat, 30 Dec 2006 20:30:12 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C1BC0C2B.6846%Keir.Fraser@xxxxxxxxxxxx>
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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Accr6PfCrVSZe50lQCCwjsW6cCTt7wAHH93IAAIsHRQAIW3ZIA==
Thread-topic: [Xen-devel] Call hypercall straightly from user space
Keir Fraser write on 2006年12月30日 20:30:
> On 30/12/06 11:27 am, "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx> wrote:
> 
>> That being the case, perhaps you need a
>> well-defined register-based ABI for all ia64 hypercalls (e.g., first
>> N bytes of the first pointer-passed structs/values passed to a
>> hypercall are re-packed into a subset of the IA64's register space).
>> The disadvantage here is the need for IA64-specific repacking on the
>> Xen and the guest sides of the hypercall interface, unless we could
>> think of some very cunning way to avoid it.
> 
> Another option would be for the guest user space to know the
> virt->machine mapping for some of its address space, and use that as
> a pool to allocate hypercall buffers from. Then user space could fill
> in the xencomm descriptors for itself.
> 
> This would need special allocation in libxc for hypercall buffers
> (since they would need to come from a pinned pool of memory for which
> libxc knows the v->m mapping) but we want to add this anyway, even
> for x86 (to reduce number of mlock/munlock calls we make).


Thanks for your suggestions.
I would like to add another wrapper for some hypercalls, 
And after hypercall buffer is implemented, then I'll follow it.

Thanks,
Anthony

> 
>  -- Keir

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