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[Xen-devel] hvm_decode() questions

To: <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] hvm_decode() questions
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Fri, 24 Nov 2006 14:03:58 +0000
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1) single-byte opcode 0x87 (xchg): What is this strange conditional

        if ( ((*(opcode+1)) & 0xc7) == 5 )

supposed to address? xchg has absolutely symmetric operands.

2) two-byte opcode 0xB7 (movzx): What is this dependency on rex
bit 3 doing here? Apparently this was based on Intel's (broken)
documentation - the source operand is always 16 bits.

Unless someone can explain these, I'll send a patch to remove them.

Jan

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