[libvirt] [PATCH] cpu: Add support for al57 Intel features

Feng, Shaohe shaohe.feng at intel.com
Fri Jan 19 14:28:39 UTC 2018

On 2018年01月09日 18:40, Jiri Denemark wrote:
> On Mon, Jan 08, 2018 at 19:06:43 +0800, Feng, Shaohe  wrote:
>> On 2018年01月05日 02:52, John Ferlan wrote:
>>> On 12/17/2017 06:02 PM, Shaohe Feng wrote:
>>>> We can start qemu with a "cpu,+la57" to set 57-bit vitrual address
>>>> space. So VM can be aware that it need to enable 5-level paging.
>>>> Corresponding QEMU commits:
>>>>           al57 6c7c3c21f95dd9af8a0691c0dd29b07247984122
>>>> ---
>>>>    src/cpu/cpu_map.xml | 3 +++
>>>>    1 file changed, 3 insertions(+)
>>> I think if you go through history of cpu_map.xml changes you'll find
>>> when a new feature is added there are tests added as well - this would
>>> thus seemingly need a test adjustment as well.
>> Thanks John.
>> Will add tests.
> Adding such test usually means you go to tests/cputestdata/ directory
> and run "./cpu-gather.sh | ./cpu-parse.sh" which will produce several
> data files. Then you add a new test case in tests/cputest.c for this new
> CPU and regenerate the files with expected results. If you do this
> before adding the new feature, the patch which will then add it will
> nicely show the new feature gets added into the expected results of the
> new CPU test.
> Don't forget to install cpuid tool and make sure you have the latest
> upstream qemu installed in the system.
> Jirka

Hi Jirka,

I went through the tests/cputestdata/ directory and found it’s for 
defining features for different CPU models.

However, the la57 feature is not included in any current CPUs. So I 
think we can get waived for the tests changes?

I check la57 on my Haswell platform it show

$ qemu-system-x86_64 -enable-kvm  -cpu Haswell,+la57,check
warning: host doesn't support requested feature: CPUID.07H:ECX.la57 [bit 16]


Shaohe Feng
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20180119/68594535/attachment-0001.htm>

More information about the libvir-list mailing list