Thank you, that helped!
I checked that 0x122 corresponds with a new MSR introduced by Intel to disable
TSX, called MSR_IA32_TSX_CTRL . I have also found that in kernel 5.5 there's
been a series of changes to hard-disable TSX inside KVM guests with
MSR_IA32_TSX_CTRL (merged to mainline in
El vie., 30 oct. 2020 a las 23:56, Bronek Kozicki
() escribió:
>
> I recently tried upgrading from vanilla LTS kernel 5.4 to vanilla 5.8 and
> found that my virtual machines "stutter" when they did not previously. The
> hypervisor is configured with tickless kernel (NO_HZ_FULL) and physical
