From: Andi Kleen <andi@firstfloor.org>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Xen-devel <xen-devel@lists.xensource.com>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Jesse Barnes <jbarnes@virtuousgeek.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [GIT PULL] xen /proc/mtrr implementation
Date: Wed, 20 May 2009 10:16:26 +0200 [thread overview]
Message-ID: <87tz3gnq91.fsf@basil.nowhere.org> (raw)
In-Reply-To: <4A11A3F8.1010202@goop.org> (Jeremy Fitzhardinge's message of "Mon, 18 May 2009 11:07:52 -0700")
Jeremy Fitzhardinge <jeremy@goop.org> writes:
> arch/x86 already defines an mtrr_ops, which defines how to manipulate
> the MTRR registers. There are currently several implementations of
> that interface. In Xen the MTRR registers belong to the hypervisor,
> but it allows a privileged kernel to modify them via hypercalls.
One part that's unclear to me in this discussion. Could you perhaps
clarify Jeremy?:
Even Dom0 is not continuous in physical memory, but mapped page by page
except for swiotlb mappings. But MTRRs are fundamentally a way
to change attributes for large physically continous mappings. How do these
two meet?
After all when you change a MTRR for a given range of memory
linux sees as continuous it isn't necessarily in Xen.
Is this new interface only defined for swiotlb or MMIO mappings?
If yes did you check the drivers only actually set it on
swiotlb or MMIO (that seems dubious to me)?
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-05-20 8:16 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-12 23:27 [GIT PULL] xen /proc/mtrr implementation Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 1/6] xen: set cpu_callout_mask to make mtrr work Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 2/6] xen mtrr: Use specific cpu_has_foo macros instead of generic cpu_has() Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 3/6] xen mtrr: Use generic_validate_add_page() Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 4/6] xen mtrr: Implement xen_get_free_region() Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 5/6] xen mtrr: Add xen_{get,set}_mtrr() implementations Jeremy Fitzhardinge
2009-05-12 23:27 ` [PATCH 6/6] xen mtrr: Kill some unnecessary includes Jeremy Fitzhardinge
2009-05-13 13:30 ` [GIT PULL] xen /proc/mtrr implementation Ingo Molnar
2009-05-13 14:39 ` Jeremy Fitzhardinge
2009-05-15 18:27 ` Ingo Molnar
2009-05-15 20:09 ` Jeremy Fitzhardinge
2009-05-15 23:26 ` Eric W. Biederman
2009-05-15 23:49 ` Jeremy Fitzhardinge
2009-05-16 3:22 ` Jesse Barnes
2009-05-16 4:26 ` Eric W. Biederman
2009-05-16 18:22 ` Jesse Barnes
2009-05-18 5:02 ` Jeremy Fitzhardinge
2009-05-18 4:57 ` Jeremy Fitzhardinge
2009-05-18 8:59 ` Ingo Molnar
2009-05-18 13:17 ` [Xen-devel] " Jan Beulich
2009-05-18 17:51 ` Chris Wright
2009-05-18 18:07 ` Jeremy Fitzhardinge
2009-05-19 9:59 ` Ingo Molnar
2009-05-19 10:22 ` [Xen-devel] " Jan Beulich
2009-05-19 11:08 ` Ingo Molnar
2009-05-19 12:04 ` Gerd Hoffmann
2009-05-19 12:26 ` Ingo Molnar
2009-05-19 12:32 ` Alan Cox
2009-05-19 12:37 ` Ingo Molnar
2009-05-19 13:21 ` Gerd Hoffmann
2009-05-19 13:31 ` Ingo Molnar
2009-05-19 13:51 ` Gerd Hoffmann
2009-05-19 14:17 ` Ingo Molnar
2009-05-19 14:55 ` Gerd Hoffmann
2009-05-19 15:24 ` Ingo Molnar
2009-05-20 8:01 ` Gerd Hoffmann
2009-05-20 16:35 ` Jeremy Fitzhardinge
2009-05-20 16:12 ` Jeremy Fitzhardinge
2009-05-20 8:16 ` Andi Kleen [this message]
2009-05-20 16:39 ` Jeremy Fitzhardinge
2009-05-20 22:52 ` Andi Kleen
2009-05-20 22:49 ` Jeremy Fitzhardinge
2009-05-20 23:03 ` 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=87tz3gnq91.fsf@basil.nowhere.org \
--to=andi@firstfloor.org \
--cc=ebiederm@xmission.com \
--cc=hpa@zytor.com \
--cc=jbarnes@virtuousgeek.org \
--cc=jeremy@goop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
--cc=xen-devel@lists.xensource.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.