Re: [Xen-devel] [PATCH 2/2] x86/HVM: re-order operations in hvm_ud_intercept()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 08/06/16 14:43, Jan Beulich wrote:
> Don't fetch CS explicitly, leverage the fact that hvm_emulate_prepare()
> already does (and that hvm_virtual_to_linear_addr() doesn't alter it).
>
> At once increase the length passed to hvm_virtual_to_linear_addr() by
> one: There definitely needs to be at least one more opcode byte, and we
> can avoid missing a wraparound case this way.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

I looked into this when you suggested it, but it latches the wrong eip
in the emulation state, and you will end up re-emulating the ud2a
instruction, rather than the following instruction.

I would be tempted just to leave this code in its current condition.

~Andrew

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