From: Keir Fraser <keir.fraser@eu.citrix.com>
To: "Oehrlein, Scott" <scott.oehrlein@intel.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: Question about PV guest accessing /dev/mem
Date: Wed, 28 Jul 2010 07:49:14 +0100 [thread overview]
Message-ID: <C875917A.1BCEF%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <41885A88D9043444B138491FB10E15420496C7E674@azsmsx506.amr.corp.intel.com>
On 28/07/2010 02:37, "Oehrlein, Scott" <scott.oehrlein@intel.com> wrote:
> I can then read/write to the devices config space using logicaladdress. When
> using Xen¹s PV functionality with pciback/pcifront to assign the device to the
> guest on a platform without VT-d support, an attempt to use logicaladdress
> results in the following error in ``xm dmesg¹¹:
>
> (XEN) mm.c:1747:d23 Bad L1 flags 800000
>
> Does this mean Xen¹s mmu is not mapping gfn to mfn correctly? Or what is
> happening after the call to mmap that is different from native path?
I think that means the guest OS is trying to map a PTE with the NX bit set
when your processor does not support NX. Xen disallows that, and it would be
a bug in the guest (Linux 2.6.34 in this case?).
-- Keir
prev parent reply other threads:[~2010-07-28 6:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-28 1:37 Question about PV guest accessing /dev/mem Oehrlein, Scott
2010-07-28 6:49 ` Keir Fraser [this message]
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