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Re: [Qemu-devel] [PATCH] target-i386: add ABM to Haswell* and Broadwell*
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From: |
Eduardo Habkost |
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Subject: |
Re: [Qemu-devel] [PATCH] target-i386: add ABM to Haswell* and Broadwell* CPU models |
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Date: |
Mon, 28 Sep 2015 15:04:38 -0300 |
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User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Mon, Sep 28, 2015 at 02:00:18PM +0200, Paolo Bonzini wrote:
> ABM is only implemented as a single instruction set by AMD; all AMD
> processors support both instructions or neither. Intel considers POPCNT
> as part of SSE4.2, and LZCNT as part of BMI1, but Intel also uses AMD's
> ABM flag to indicate support for both POPCNT and LZCNT. It has to be
> added to Haswell and Broadwell because Haswell, by adding LZCNT, has
> completed the ABM.
>
> Tested with "qemu-kvm -cpu Haswell-noTSX,enforce" (and also with older
> machine types) on an Haswell-EP machine.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
Reviewed-by: Eduardo Habkost <address@hidden>
Applied to x86 tree, thanks!
--
Eduardo