Re: [PATCH 1/3] x86/hvm/trace: Use a different trace type for AMD processors

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 26/04/2024 4:29 pm, George Dunlap wrote:
> On Fri, Apr 26, 2024 at 4:18 PM Andrew Cooper <andrew.cooper3@xxxxxxxxxx> 
> wrote:
>> On 26/04/2024 3:32 pm, George Dunlap wrote:
>>> In xenalyze, first remove the redundant call to init_hvm_data();
>>> there's no way to get to hvm_vmexit_process() without it being already
>>> initialized by the set_vcpu_type call in hvm_process().
>>>
>>> Replace this with set_hvm_exit_reson_data(), and move setting of
>>> hvm->exit_reason_* into that function.
>>>
>>> Modify hvm_process and hvm_vmexit_process to handle all four potential
>>> values appropriately.
>>>
>>> If SVM entries are encountered, set opt.svm_mode so that other
>>> SVM-specific functionality is triggered.
>> Given that xenalyze is now closely tied to Xen, and that we're
>> technically changing the ABI here, is there any point keeping `--svm-mode` ?
>>
>> I'm unsure of the utility of reading the buggy trace records from an
>> older version of Xen.
> Yeah, I thought about that.  If nobody argues to keep it, I guess I'll
> rip it out for v2.

That's the way I'd suggest going.
>>> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxx>
>>> ---
>>> NB that this patch goes on top of Andrew's trace cleanup series:
>>>
>>> https://lore.kernel.org/xen-devel/20240318163552.3808695-1-andrew.cooper3@xxxxxxxxxx/
>> The delta in Xen is trivial.  I'm happy if you want to commit this, and
>> I can rebase over it.
> It's trivial in part *because of* your series.  Without your series I
> would have had to do a bunch of munging around with DO_TRC_BLAH_BLAH
> to make it compile.  In fact, I started doing it directly on staging,
> but quickly moved onto your series to save myself some time. :-)

Ah.  I'll be refreshing mine next week.  Given that it's missed
everything since 4.16, I'm not intending to let it miss this one...

But I've still got a few things which need to go out before the
past-post deadline.

~Andrew