Subject: Re: powerpc/time: Fix clockevent_decrementer initalisation for PR KVM

From: Michael Ellerman <[email-masked]>
Date: Mon, 22 Oct 2018 20:40:10 +1100 (AEDT)

On Fri, 2018-10-19 at 04:23:19 UTC, Michael Ellerman wrote:
> In the recent commit 8b78fdb045de ("powerpc/time: Use
> clockevents_register_device(), fixing an issue with large
> decrementer") we changed the way we initialise the decrementer
> clockevent(s).
> 
> We no longer initialise the mult & shift values of
> decrementer_clockevent itself.
> 
> This has the effect of breaking PR KVM, because it uses those values
> in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
> mid-way through boot.
> 
> For now fix it by assigning back to decrementer_clockevent the mult
> and shift values.
> 
> Fixes: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
> Signed-off-by: Michael Ellerman <[email-masked]>
> Acked-by: Anton Blanchard <[email-masked]>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/b4d16ab58c41ff0125822464bdff07

cheers