From: Joanna Rutkowska <joanna@invisiblethingslab.com>
To: Keir Fraser <keir.xen@gmail.com>
Cc: "Cihula, Joseph" <joseph.cihula@intel.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"Kay, Allen M" <allen.m.kay@intel.com>,
Rafal Wojtczuk <rafal@invisiblethingslab.com>,
Jan Beulich <JBeulich@novell.com>
Subject: Re: Re: [PATCH][VTD] force boot to fail if interrupt remapping cannot be enabled when iommu=force
Date: Thu, 28 Apr 2011 20:26:43 +0200 [thread overview]
Message-ID: <4DB9B163.4040908@invisiblethingslab.com> (raw)
In-Reply-To: <C9DF5CCF.16F23%keir.xen@gmail.com>
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On 04/28/11 19:05, Keir Fraser wrote:
> On 28/04/2011 00:42, "Kay, Allen M" <allen.m.kay@intel.com> wrote:
>
>> Force Xen boot to fail if interrupt remapping fails to enable and the
>> following are true: iommu=force is set as xen boot parameter, VT-d engine HW
>> is interrupt remapping capable, DMAR_INTR_REMAP bit is set in DMAR flags.
>> This forces iommu=force boot instances has interrupt remapping enabled if HW
>> and BIOS supports it.
>
> If HW and BIOS support it, why would it fail to be enabled? This doesn't
> look like a particularly useful panic() path. If interrupt remapping is so
> important, perhaps iommu=force should unconditionally require it, and panic
> in its absence regardless of platform features?
Indeed, seems to me like a desired behavior.
j.
> As it is, this looks like a
> panic that is never realistically going to trigger.
>
> -- Keir
>
>> Signed-off-by: Allen Kay <allen.m.kay@intel.com>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
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next prev parent reply other threads:[~2011-04-28 18:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-27 23:42 [PATCH][VTD] force boot to fail if interrupt remapping cannot be enabled when iommu=force Kay, Allen M
2011-04-28 17:05 ` Keir Fraser
2011-04-28 18:26 ` Joanna Rutkowska [this message]
2011-04-28 18:58 ` Cihula, Joseph
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