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RE: [Xen-devel] [PATCH] tweak memory error correction field in the SMBIO

To: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH] tweak memory error correction field in the SMBIOS data
From: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Date: Fri, 27 Nov 2009 09:50:27 +0800
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Thread-topic: [Xen-devel] [PATCH] tweak memory error correction field in the SMBIOS data
Paolo Bonzini wrote:
> On 11/26/2009 02:21 AM, Jiang, Yunhong wrote:
>> When the host detected 1 bit memory error, it may raises #MCE
> Does MCE distinguish single- or multi-bit errors?  Multi-bit ECC makes
> errors less likely, not impossible.

That depends on implementation, I think.

> I know it's not optimal, I just don't think it's worth the effort.
> Besides it could become wrong anyway after migration.

Noticed Andi's response for the mail that "It would be better if you checked 
that on the host and then set it appropiately in the guest too." and agree with 
this idea.

For migration, I think this only extend the host requirement from CPU to 
memory. For example, we can't migrate guest from host supporting SSE4 
instruciton to host does not support it if we don't limit guest's CPUID.

Also, another potential issue is, not sure if Windows guest will utilize the 
ECC support or not, although it should not.

BTW, I'm not against the change, which is not critical.


> Paolo
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