From: Tim Deegan <tim@xen.org>
To: "Kalev, Leonid" <Leonid.Kalev@ca.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Subject: Re: Help needed debugging "EPT Misconfiguration" exception on Intel CPU
Date: Thu, 2 Feb 2012 11:26:20 +0000 [thread overview]
Message-ID: <20120202112620.GF48883@ocelot.phlegethon.org> (raw)
In-Reply-To: <4F218876.8090606@ca.com>
At 17:08 +0000 on 26 Jan (1327597687), Kalev, Leonid wrote:
> (XEN) EPT Misconfiguration, gpa=00000000feffe000
> (XEN) domain->...->eptp = 0x431b3d01e
> (XEN) vmread(EPT_POINTER) = 0x431b3d01e
>
> EPTP bits:
> 0-2 = 6; mem type (0 = UC, 6=WB, all other = invalid)
> 5-3 = 3 (should be = 3 (walk length - 1))
> 6-11 = 0 reserved
> 12-39 = 0x431b3d; addr of EPT PML4
> 40-64 = 0 ; reserved (40 is the addr sz of the CPU here, may vary on other CPUs,
> max=48)
>
> (XEN) p2m-ept.c:649:d3 Walking EPT tables for domain 3 gfn feffe
> (XEN) p2m-ept.c:668:d3 epte 1c00000431b3c007
> 0-2 = 7: access allowed: rwx
> 3-7 = 0: reserved
> 8-11 = 0: ignored
> x-12 = 431b3c: address of next level EPT
> 51-x - 0
> 52-63 - ignored
> (XEN) p2m-ept.c:668:d3 epte 1c000004374fb007
> (XEN) p2m-ept.c:668:d3 epte 1c000004374fa007
> (XEN) p2m-ept.c:668:d3 epte 1c10000c213ee037 0-2 = 7: rwx
> 10000000000 (nb: addr size limit - 40 bits for
> this CPU, we're way below)
> 3-5 = 6: type (0 = UC; 1 = WC; 4 = WT;
> 5 = WP; 6 = WB)
> 6 = 0:
> 7-11 =0: (ignored)
> mfn=c213ee, (looks valid, mem extends from 100000 to
> c40000, see mem map below)
> 52=1; 52-63 should be ignored
Yeah, those entries look fine. Certainly they don't have any of the
problems listed in section 25.2.3.1 of the SDM under "EPT
Misconfigurations", so I suspect there must be something odd about the
non-production CPU you're using.
Tim.
prev parent reply other threads:[~2012-02-02 11:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-26 17:08 Help needed debugging "EPT Misconfiguration" exception on Intel CPU Kalev, Leonid
2012-02-01 16:25 ` Konrad Rzeszutek Wilk
2012-02-02 11:26 ` Tim Deegan [this message]
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