Re: [PATCH v1 1/2] powerpc/64s: system call rfscv workaround for TM bugs

2021-09-19 Thread Michael Ellerman
On Wed, 8 Sep 2021 20:17:17 +1000, Nicholas Piggin wrote: > The rfscv instruction does not work correctly with the fake-suspend mode > in POWER9, which can end up with the hypervisor restoring an incorrect > checkpoint. > > Work around this by setting the _TIF_RESTOREALL flag if a system call > re

Re: [PATCH v1 1/2] powerpc/64s: system call rfscv workaround for TM bugs

2021-09-17 Thread Daniel Axtens
Nicholas Piggin writes: > The rfscv instruction does not work correctly with the fake-suspend mode > in POWER9, which can end up with the hypervisor restoring an incorrect > checkpoint. If I understand correctly from commit 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bug

[PATCH v1 1/2] powerpc/64s: system call rfscv workaround for TM bugs

2021-09-08 Thread Nicholas Piggin
The rfscv instruction does not work correctly with the fake-suspend mode in POWER9, which can end up with the hypervisor restoring an incorrect checkpoint. Work around this by setting the _TIF_RESTOREALL flag if a system call returns to a transaction active state, causing rfid to be used instead o