netdev - Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 20 Mar 2007 00:42:48 +0100
From:	Andi Kleen <ak@....de>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	David Miller <davem@...emloft.net>, mingo@...e.hu,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org,
	virtualization@...ts.osdl.org, xen-devel@...ts.xensource.com,
	chrisw@...s-sol.org, zach@...are.com, anthony@...emonkey.ws,
	torvalds@...ux-foundation.org, netdev@...r.kernel.org
Subject: Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable

> Possibly not, but I'd like to be able to say with confidence that
> running a PARAVIRT kernel on bare hardware has no performance loss
> compared to running a !PARAVIRT kernel.  There's the case of small
> instruction sequences which have been replaced with calls (such as
> sti/cli/push;popf/etc), 

My guess is that most critical pushf/popf are in spin_lock_irqsave(). It would 
be possible to special case that one -- inline it -- and use out of line
versions for all the others.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html