On 15/07/20 23:46, Nadav Amit wrote:
>> On Jul 15, 2020, at 1:52 PM, Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote:
>>
>> Explicitly zero cr4 in prepare_64() instead of "zeroing" it in the
>> common enter_long_mode(). Clobbering cr4 in enter_long_mode() breaks
>> switch_to_5level(), which sets cr4.LA57 before calling enter_long_mode()
>> and obviously expects cr4 to be preserved.
>>
>> Fixes: d86ef58 ("cstart: do not assume CR4 starts as zero")
>> Cc: Nadav Amit <namit@xxxxxxxxxx>
>> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
>> ---
>>
>> Two lines of code, two bugs. I'm pretty sure Paolo should win some kind
>> of award. :-D
>
> I guess it is my fault for stressing him to push the changes so I can run it
> on the AMD machine that was lended to me.
>
> Reviewed-by: Nadav Amit <namit@xxxxxxxxxx>
I can blame you for this one but not for cstart.S. At least this made
me realize that the bus factor is a bit low. Well, if I were really hit
by a bus I guess you guys would figure out something, but for more short
term issues I should ensure that someone else has write access to
kvm.git. If no one volunteers, I'll ask Konstantin Ryabitsev to give
back commit access to Marcelo Tosatti for emergency cases.
Paolo
