On Fri, Aug 25, 2017 at 07:52:12PM +1000, Paul Mackerras wrote:
> Commit 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large
> decrementer mode", 2017-05-22) added code to treat the hypervisor
> decrementer (HDEC) as a 64-bit value on POWER9 rather than 32-bit.
> Unfortunately, that commit missed one place where HDEC is treated
> as a 32-bit value. This fixes it.
>
> This bug should not have any user-visible consequences that I can
> think of, beyond an occasional unnecessary exit to the host kernel.
> If the hypervisor decrementer has gone negative, then the bottom
> 32 bits will be negative for about 4 seconds after that, so as
> long as we get out of the guest within those 4 seconds we won't
> conclude that the HDEC interrupt is spurious.
>
> Reported-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
> Fixes: 2f2724630f7a ("KVM: PPC: Book3S HV: Cope with host using large decrementer mode")
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Patch applied to my kvm-ppc-next branch.
Paul.
