From: Scott Wood <scottwood@freescale.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org, Alexander Graf <agraf@suse.de>,
Stuart Yoder <stuart.yoder@freescale.com>
Subject: Re: [PATCH] powerpc/booke: Eliminate rfi from exception entry path.
Date: Tue, 10 Jul 2012 19:41:17 -0500 [thread overview]
Message-ID: <4FFCCBAD.40504@freescale.com> (raw)
In-Reply-To: <1341967010.18850.19.camel@pasglop>
On 07/10/2012 07:36 PM, Benjamin Herrenschmidt wrote:
> On Tue, 2012-07-10 at 19:34 -0500, Scott Wood wrote:
>> Unlike classic, we don't really need the MSR change to be atomic with the
>> branch. This eliminates a trap as a KVM guest (in the absence of
>> hardware hypervisor extensions), where mtmsr is paravirtualized but rfi
>> is not. For a virtualized guest without any paravirtualization, this
>> eliminates an additional two traps (SRR0/1).
>
> In fact, I wonder, what do we write into the MSR at this point that
> wasn't already in it in BookE ? RI ? I wonder if we could get away
> without the mtmsr alltogether...
Doesn't EE get set there for some exceptions?
-Scott
next prev parent reply other threads:[~2012-07-11 0:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-11 0:34 [PATCH] powerpc/booke: Eliminate rfi from exception entry path Scott Wood
2012-07-11 0:36 ` Benjamin Herrenschmidt
2012-07-11 0:41 ` Scott Wood [this message]
2012-07-11 0:53 ` Benjamin Herrenschmidt
2012-07-11 0:44 ` Alexander Graf
2012-07-11 0:47 ` Scott Wood
2012-07-11 0:54 ` Benjamin Herrenschmidt
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=4FFCCBAD.40504@freescale.com \
--to=scottwood@freescale.com \
--cc=agraf@suse.de \
--cc=benh@kernel.crashing.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=stuart.yoder@freescale.com \
/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;
as well as URLs for NNTP newsgroup(s).