Re: [Xen-devel] [PATCH RFC] x86: Add hack to disable "Fake HT" mode

[George Dunlap <george.dunlap@xxxxxxxxxx>]

On 11/15/19 2:06 PM, Andrew Cooper wrote:
> On 15/11/2019 14:04, George Dunlap wrote:
>>>> It's not entirely uncommon to (also) consider how the resulting
>>>> diff would look like when putting together a change. And besides
>>>> the review aspect, there's also the archeology one - "git blame"
>>>> yields much more helpful results when code doesn't get moved
>>>> around more than necessary. But yes, there's no very clear "this
>>>> is the better option" here. I've taken another look at the code
>>>> before your change though - everything is already nicely in one
>>>> place with Andrew's most recent code reorg. So I'm now having an
>>>> even harder time seeing why you want to move things around again.
>>> We don't.  I've recommend twice now to have a single "else if" hunk
>>> which is nearly empty, and much more obviously a gross "make it work for
>>> 4.13" bodge.
>> The results are a tiny bit better, but not much really (see attached).
> 
> What I meant was:
> 
>> diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
>> index 312c481f1e..bc088e45f0 100644
>> --- a/tools/libxc/xc_cpuid_x86.c
>> +++ b/tools/libxc/xc_cpuid_x86.c
>> @@ -579,52 +579,71 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t 
>> domid,
>>      }
> 
> else if ( getenv() )
> {
>     ...
> }
> 
>>      else
>>      {
> 
> With no delta to this block at all.

Then we have to duplicate this code in both blocks:

        /*
         * These settings are necessary to cause earlier
HVM_PARAM_NESTEDHVM /
         * XEN_DOMCTL_disable_migrate settings to be reflected correctly in
         * CPUID.  Xen will discard these bits if configuration hasn't been
         * set for the domain.
         */
        p->extd.itsc = true;
        p->basic.vmx = true;
        p->extd.svm = true;

I won't object if that's what you guys really want.

 -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel