From: "Jan Beulich" <jbeulich@novell.com>
To: "Joerg Roedel" <joro@8bytes.org>
Cc: <mingo@elte.hu>, "Andi Kleen" <andi@firstfloor.org>,
<tglx@linutronix.de>, <linux-kernel@vger.kernel.org>,
<hpa@zytor.com>
Subject: Re: [PATCH] i386: improve double fault handling
Date: Thu, 24 Jul 2008 08:08:15 +0100 [thread overview]
Message-ID: <4888467F.76E4.0078.0@novell.com> (raw)
In-Reply-To: <20080723214320.GC13662@8bytes.org>
>>> Joerg Roedel <joro@8bytes.org> 23.07.08 23:43 >>>
>On Fri, Jul 18, 2008 at 01:30:42PM +0100, Jan Beulich wrote:
>> Make the double fault handler use CPU-specific stacks. Add some
>> abstraction to simplify future change of other exception handlers to go
>> through task gates.
>
>What is the benefit of exception handlers going through task gates?
>Hardware task switches are not very well supported in virtualization
>(e.g. its has issues in KVM and is also not in Xen for a long time).
The main goal is to get to a different stack. While at present this is done
only for the double fault, I think generally NMI and MCE should also do
so, as they may be caused by a stack access (see x86-64, which runs
them on IST stacks), and hence continuing to run on that same stack
may not allow the exception to be handled.
Jan
next prev parent reply other threads:[~2008-07-24 7:07 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-18 12:30 Jan Beulich
2008-07-18 23:24 ` H. Peter Anvin
2008-07-21 8:54 ` Jan Beulich
2008-07-21 11:05 ` Ingo Molnar
2008-07-22 10:13 ` Jan Beulich
2008-07-28 13:42 ` Ingo Molnar
2008-07-28 13:45 ` H. Peter Anvin
2008-07-28 13:59 ` Jan Beulich
2008-07-28 14:02 ` H. Peter Anvin
2008-07-28 16:28 ` Ingo Molnar
2008-07-28 22:00 ` Chuck Ebbert
2008-07-31 10:46 ` Ingo Molnar
2008-07-23 21:43 ` Joerg Roedel
2008-07-24 7:08 ` Jan Beulich [this message]
2008-07-24 13:24 ` H. Peter Anvin
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=4888467F.76E4.0078.0@novell.com \
--to=jbeulich@novell.com \
--cc=andi@firstfloor.org \
--cc=hpa@zytor.com \
--cc=joro@8bytes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tglx@linutronix.de \
/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
Powered by JetHome