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Re: [Xen-devel] [PATCH][HAP][2/2] fix CR4 initialization when hap is on

To: "Huang2, Wei" <Wei.Huang2@xxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>, Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH][HAP][2/2] fix CR4 initialization when hap is on
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Tue, 27 Mar 2007 17:13:43 +0100
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Thread-topic: [Xen-devel] [PATCH][HAP][2/2] fix CR4 initialization when hap is on
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This seems an odd change. The earlier setting of CR4 in construct_vmcb() already masks out paging-related bits. So why would the remaining bits’ behaviour differ between hap and shadow paging modes? It would seem to me that either CR4 should be zero at start-of-day in all cases (seems quite likely to me as that’s what happens in a native system), or the existing code should be okay in both cases.

 -- Keir

On 22/3/07 16:13, "Huang2, Wei" <Wei.Huang2@xxxxxxx> wrote:

This patch initializes VMCB CR4 and shadow CR4 with 0 when VMCB is being constructed under nested paging mode. It complies with recent reset_to_realmode change in hvmloader.

Signed-off-by: Wei Huang (wei.huang2@xxxxxxx <mailto:wei.huang2@xxxxxxx> )


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