[libvirt] [PATCH] Drop hle feature for Haswell CPUs

[Daniel P. Berrange]

On Tue, Dec 16, 2014 at 01:33:15PM +0100, Guido Günther wrote:
> The intel-microcode 3.20140913.1 update disables TSX-NI (transactional
> memory instructions). When a server running libvirt is rebooted with
> this update, libvirt no longer considers the machine to have a Haswell
> CPU:
> 
>  # virsh capabilities | grep -A1 '<arch>x86_64'
>     <arch>x86_64</arch>
>     <model>SandyBridge</model>
> 
> Since Intel disables the feature on their CPUs we shouldn't check for it
> as well to keep VMs using Haswell working.
> 
> This was debugged and reported by Chris Boot at
> http://bugs.debian.org/773189
> ---
>  src/cpu/cpu_map.xml | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/src/cpu/cpu_map.xml b/src/cpu/cpu_map.xml
> index bd9b056..f41dbce 100644
> --- a/src/cpu/cpu_map.xml
> +++ b/src/cpu/cpu_map.xml
> @@ -507,7 +507,6 @@
>        <feature name='movbe'/>
>        <feature name='fsgsbase'/>
>        <feature name='bmi1'/>
> -      <feature name='hle'/>
>        <feature name='avx2'/>
>        <feature name='smep'/>
>        <feature name='bmi2'/>

NACK.  We can not change existing models in cpu_map.xml because that
results in a guest ABI change.

Regards,
Daniel
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