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RE: [Xen-devel] x2apic mode vs. interrupt remapping

To: Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: RE: [Xen-devel] x2apic mode vs. interrupt remapping
From: "Zhang, Xiantao" <xiantao.zhang@xxxxxxxxx>
Date: Wed, 3 Mar 2010 22:27:35 +0800
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Thread-topic: [Xen-devel] x2apic mode vs. interrupt remapping
Jan Beulich wrote:
>>>> "Zhang, Xiantao" <xiantao.zhang@xxxxxxxxx> 03.03.10 15:09 >>>
>> When iommu_supports_eim is called in enable_x2apic, drhd is already
>> parsed in acpi_boot_init,
> Provided there is any - in the given case there is none. Perhaps the
> function should also return 0 if the list of drhd-s is empty?

Yeah, if the drhd list is empty, it should return 0 instead of the default 1.  
The condition check maybe need enhancement. 

>> so iommu_supports_eim should return hardware's real capability. That
>> is to say, if eim is no supported on platform, x2apic shouldn't be
>> enabled at all.
> Jan

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