public inbox for kexec@lists.infradead.org
 help / color / mirror / Atom feed
From: David Vrabel <david.vrabel@citrix.com>
To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	Eric Biederman <ebiederm@xmission.com>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: [Xen-devel] [RFC PATCH 0/3] Improve kexec support in Xen hypervisor
Date: Wed, 16 Jan 2013 17:48:38 +0000	[thread overview]
Message-ID: <50F6E7F6.7060905@citrix.com> (raw)
In-Reply-To: <1358355772.13856.11.camel@zakaz.uk.xensource.com>

On 16/01/13 17:02, Ian Campbell wrote:
> On Wed, 2013-01-16 at 16:29 +0000, David Vrabel wrote:
>> Since the kexec hypercall is for use by dom0 I have removed the
>> implementation of the old load/unload ops and thus guests will require
>> updated kexec-tools to load images.  Is this acceptable? 
> 
> How hard would it be to also support the old interface for the benefit
> of old kernels and userspaces (e.g. existing distros)?

There's an easy way (see patch 1), but it doesn't have full
compatibility as it no longer executes the code page supplied by the
guest.  This won't matter with Linux guests as their code pages can be
replaced by the code in Xen, but may matter with some more obscure
guests that do unusual things in their code pages (are there any like
this -- I doubt it?).

Full compatibility is possible and not that hard.  Is it actually worth
it though?  Will there be people updating Xen to 4.3 and unable to
update their kernel or userspace tools?

> Rather than a _v2 suffix we have in the past renamed the old ones
> _compat and introduced the new ones, with appropriate use of
> __XEN_INTERFACE_VERSION__ to paper over things for old users.
> 
> See __HYPERVISOR_sched_op for example.

Ok. I'll look at this.

David

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

  reply	other threads:[~2013-01-16 17:48 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-16 16:29 [RFC PATCH 0/3] Improve kexec support in Xen hypervisor David Vrabel
2013-01-16 16:29 ` [PATCH 1/3] kexec: extend hypercall with improved load/unload ops David Vrabel
2013-01-17 12:28   ` Daniel Kiper
2013-01-17 14:50     ` David Vrabel
2013-01-17 15:17       ` Daniel Kiper
2013-01-17 17:53         ` David Vrabel
2013-01-18  9:44           ` Daniel Kiper
2013-01-18  9:50           ` [Xen-devel] " Ian Campbell
2013-01-18 19:01           ` Eric W. Biederman
2013-01-17 12:33   ` [Xen-devel] " Ian Campbell
2013-01-16 16:29 ` [PATCH 2/3] kexec: remove kexec_load and kexec_unload ops David Vrabel
2013-01-16 16:29 ` [PATCH 3/3] libxc: add API for kexec hypercall David Vrabel
2013-01-16 16:59   ` [Xen-devel] " Ian Campbell
2013-01-16 16:33 ` [RFC PATCH 0/3] Improve kexec support in Xen hypervisor David Vrabel
2013-01-16 17:02 ` [Xen-devel] " Ian Campbell
2013-01-16 17:48   ` David Vrabel [this message]
2013-01-17  9:35     ` Ian Campbell
2013-01-17 10:46     ` Jan Beulich
2013-01-17 10:51       ` Jan Beulich
2013-01-17 11:27 ` Daniel Kiper
2013-01-17 11:37   ` [Xen-devel] " Andrew Cooper
2013-01-17 12:59     ` Daniel Kiper
2013-01-17 13:01   ` David Vrabel
2013-01-17 13:25     ` Eric W. Biederman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=50F6E7F6.7060905@citrix.com \
    --to=david.vrabel@citrix.com \
    --cc=Ian.Campbell@citrix.com \
    --cc=daniel.kiper@oracle.com \
    --cc=ebiederm@xmission.com \
    --cc=kexec@lists.infradead.org \
    --cc=xen-devel@lists.xen.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox