From: Jamie Lokier <jamie@shareable.org>
To: Paul Brook <paul@codesourcery.com>
Cc: Cam Macdonell <cam@cs.ualberta.ca>,
qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [PATCH] Inter-VM shared memory PCI device
Date: Tue, 9 Mar 2010 19:00:30 +0000 [thread overview]
Message-ID: <20100309190030.GB11042@shareable.org> (raw)
In-Reply-To: <201003081304.45862.paul@codesourcery.com>
Paul Brook wrote:
> > However, coherence could be made host-type-independent by the host
> > mapping and unampping pages, so that each page is only mapped into one
> > guest (or guest CPU) at a time. Just like some clustering filesystems
> > do to maintain coherence.
>
> You're assuming that a TLB flush implies a write barrier, and a TLB miss
> implies a read barrier. I'd be surprised if this were true in general.
The host driver itself can issue full barriers at the same time as it
maps pages on TLB miss, and would probably have to interrupt the
guest's SMP KVM threads to insert a full barrier when broadcasting a
TLB flush on unmap.
-- Jamie
next prev parent reply other threads:[~2010-03-09 19:00 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-05 23:52 [Qemu-devel] [PATCH] Support adding a file to qemu's ram allocation Cam Macdonell
2010-03-05 23:52 ` [Qemu-devel] [PATCH] Inter-VM shared memory PCI device Cam Macdonell
2010-03-07 22:53 ` Paul Brook
2010-03-08 1:45 ` Jamie Lokier
2010-03-08 9:48 ` Alexander Graf
2010-03-08 9:54 ` Jamie Lokier
2010-03-08 10:57 ` Alexander Graf
2010-03-09 21:41 ` Anthony Liguori
2010-03-08 13:04 ` Paul Brook
2010-03-09 19:00 ` Jamie Lokier [this message]
2010-03-08 9:52 ` Avi Kivity
2010-03-08 13:03 ` Paul Brook
2010-03-08 13:16 ` Avi Kivity
2010-03-09 20:11 ` Jamie Lokier
2010-03-09 21:44 ` Anthony Liguori
2010-03-10 9:25 ` Avi Kivity
2010-03-10 17:13 ` Anthony Liguori
2010-03-10 17:30 ` Avi Kivity
2010-03-10 17:41 ` Paul Brook
2010-03-11 6:33 ` Avi Kivity
2010-03-11 12:21 ` Paul Brook
2010-03-09 20:12 ` Jamie Lokier
2010-03-10 0:03 ` Paul Brook
2010-03-10 4:38 ` Cam Macdonell
2010-03-10 9:29 ` Avi Kivity
2010-03-10 11:13 ` Paul Brook
2010-03-11 3:10 ` Jamie Lokier
2010-03-11 4:37 ` Nick Piggin
2010-03-11 14:38 ` malc
2010-03-08 9:56 ` [Qemu-devel] " Avi Kivity
2010-03-08 17:57 ` Cam Macdonell
2010-03-09 10:29 ` Avi Kivity
[not found] ` <8286e4ee1003090724m1ef0b571g8b705a24e36e1753@mail.gmail.com>
2010-03-09 15:27 ` [Qemu-devel] " Cam Macdonell
2010-03-09 17:28 ` [Qemu-devel] " Avi Kivity
2010-03-09 17:34 ` Anthony Liguori
2010-03-09 18:34 ` Cam Macdonell
2010-03-10 9:21 ` Avi Kivity
2010-03-10 16:36 ` Cam Macdonell
2010-03-11 6:49 ` Avi Kivity
2010-03-09 12:49 ` Arnd Bergmann
2010-03-09 13:03 ` Avi Kivity
2010-03-09 16:44 ` Cam Macdonell
2010-03-10 14:04 ` Arnd Bergmann
2010-03-11 6:50 ` Avi Kivity
2010-03-11 12:57 ` Arnd Bergmann
2010-03-11 13:07 ` Avi Kivity
2010-03-11 14:32 ` Arnd Bergmann
2010-03-08 9:53 ` [Qemu-devel] Re: [PATCH] Support adding a file to qemu's ram allocation Avi Kivity
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=20100309190030.GB11042@shareable.org \
--to=jamie@shareable.org \
--cc=cam@cs.ualberta.ca \
--cc=kvm@vger.kernel.org \
--cc=paul@codesourcery.com \
--cc=qemu-devel@nongnu.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;
as well as URLs for NNTP newsgroup(s).