From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: "Pasi Kärkkäinen" <pasik@iki.fi>
Cc: xen-devel@lists.xensource.com
Subject: Re: Intel Xeon E5620 CPU and VT-d (IOMMU) support?
Date: Wed, 2 Jun 2010 14:02:58 -0400 [thread overview]
Message-ID: <20100602180258.GA31974@phenom.dumpdata.com> (raw)
In-Reply-To: <20100602164007.GM17817@reaktio.net>
On Wed, Jun 02, 2010 at 07:40:07PM +0300, Pasi Kärkkäinen wrote:
> Hello,
>
> I'm planning to upgrade my testbox and I was checking for hardware options.
> Can someone verify if Intel Xeon E5620 CPU supports (or doesn't support) VT-d IOMMU?
>
> I'm asking because Intel website doesn't mention VT-d for E5620:
> http://ark.intel.com/Product.aspx?id=47925
>
> .. but it does for some (older) CPUs (E5520):
> http://ark.intel.com/Product.aspx?id=40200
>
> The chipset I'm planning to get (Intel 5520 Tylersburg) does have VT-d / IOMMU support listed.
So one thing I didn't know was that you need equivalant number of DMAR
entries for the IO-APICs on your motherboard. If you have three IO-APICs (like, this
SuperMicro X8something), you need three DMAR entries - mine only has
one. Which means that VT-d is turned off (Xen and both Linux baremetal
do this) as it can't do its magic on the other IO-APICs to re-route the IRQs
to the guest. You can hack the code to re-enable it, but then you must
disable the x2APIC.
next prev parent reply other threads:[~2010-06-02 18:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-02 16:40 Intel Xeon E5620 CPU and VT-d (IOMMU) support? Pasi Kärkkäinen
2010-06-02 18:02 ` Konrad Rzeszutek Wilk [this message]
2010-06-03 9:33 ` Andreas Olsowski
2010-06-03 9:49 ` Pasi Kärkkäinen
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=20100602180258.GA31974@phenom.dumpdata.com \
--to=konrad.wilk@oracle.com \
--cc=pasik@iki.fi \
--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.