From: Chris Wright <chrisw@sous-sol.org>
To: cody <mail.kai.huang@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>,
Roland Dreier <roland@purestorage.com>,
linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, Chris Wright <chrisw@sous-sol.org>
Subject: Re: [PATCH] intel-iommu: Default to non-coherent for domains unattached to iommus
Date: Mon, 14 Nov 2011 20:54:04 -0800 [thread overview]
Message-ID: <20111115045404.GC30247@sequoia.sous-sol.org> (raw)
In-Reply-To: <4EC210CB.1010409@gmail.com>
* cody (mail.kai.huang@gmail.com) wrote:
> On 11/11/2011 05:20 PM, David Woodhouse wrote:
> >On Fri, 2011-11-11 at 17:08 -0800, Chris Wright wrote:
> >>On a slightly separate, but performance related note...have you ever
> >>tried using the hw queue? Currently we only have a sw queue, but the
> >>submission path for invalidations doesn't really queue (unless I missed
> >>it). It seems to pull from the software queue and submit/wait,
> >>submit/wait...Seems simple enough to submit the whole queue and then
> >>issue the wait.
> >I have a feeling we trigger errata if we do that — although if we're
> >only doing it for an emulated IOMMU that shouldn't be an issue.
> >
> What does the emulated IOMMU here? Does it mean the emulated IOMMU
> exposed to guest VM?
Yes. So for KVM, the IOMMU emulation would be in QEMU.
thanks,
-chris
next prev parent reply other threads:[~2011-11-15 4:54 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-11 22:49 [PATCH] intel-iommu: Default to non-coherent for domains unattached to iommus Alex Williamson
2011-11-12 0:17 ` Chris Wright
2011-11-12 0:37 ` David Woodhouse
2011-11-12 0:45 ` Chris Wright
2011-11-12 0:47 ` Chris Wright
2011-11-12 0:51 ` David Woodhouse
2011-11-12 0:58 ` Chris Wright
2011-11-12 1:03 ` David Woodhouse
2011-11-12 0:46 ` Roland Dreier
2011-11-12 0:51 ` Chris Wright
2011-11-12 0:55 ` David Woodhouse
2011-11-12 1:08 ` Chris Wright
2011-11-12 1:20 ` David Woodhouse
2011-11-15 7:12 ` cody
2011-11-15 4:54 ` Chris Wright [this message]
2011-11-15 5:55 ` Kai Huang
2011-11-12 1:30 ` Roland Dreier
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