Re: text-tsx fails on Intel core 8th gen system

[Jan Beulich <jbeulich@xxxxxxxx>]

On 03.04.2024 18:41, Marek Marczykowski-Górecki wrote:
> On Wed, Apr 03, 2024 at 05:04:20PM +0200, Jan Beulich wrote:
>> On 03.04.2024 16:50, Marek Marczykowski-Górecki wrote:
>>> Hi,
>>>
>>> I've noticed that tools/tests/tsx/test-tsx fails on a system with Intel
>>> Core i7-8750H. Specific error I get:
>>>
>>>     [user@dom0 tsx]$ ./test-tsx 
>>>     TSX tests
>>>       Got 16 CPUs
>>>     Testing MSR_TSX_FORCE_ABORT consistency
>>>       CPU0 val 0
>>>     Testing MSR_TSX_CTRL consistency
>>>     Testing MSR_MCU_OPT_CTRL consistency
>>>       CPU0 val 0
>>>     Testing RTM behaviour
>>>       Got #UD
>>>       Host reports RTM, but appears unavailable
>>
>> Isn't this ...
>>
>>>     Testing PV default/max policies
>>>       Max: RTM 1, HLE 1, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       Def: RTM 0, HLE 0, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       HLE/RTM offered to guests despite not being available
>>>     Testing HVM default/max policies
>>>       Max: RTM 1, HLE 1, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       Def: RTM 0, HLE 0, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       HLE/RTM offered to guests despite not being available
>>>     Testing PV guest
>>>       Created d8
>>>       Cur: RTM 0, HLE 0, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       Cur: RTM 1, HLE 1, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>     Testing HVM guest
>>>       Created d9
>>>       Cur: RTM 0, HLE 0, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>       Cur: RTM 1, HLE 1, TSX_FORCE_ABORT 0, RTM_ALWAYS_ABORT 0, TSX_CTRL 0
>>>     [user@dom0 tsx]$ echo $?
>>>     1
>>
>> ... the reason for this?
> 
> I think so, but the question is why it behaves this way. Could be an
> issue with MSR/CPUID values presented by Xen, or values Xen gets from
> the CPU.

Can't test_rtm_behaviour() be run even without Xen underneath? Maybe this
could be run irrespective of xc_interface_open() failing?

Jan