Subject: Re: [PATCH] powerpc/icp-opal: Fix missing KVM case and harden replay

From: Balbir Singh <[email-masked]>
Date: Mon, 16 Jan 2017 21:37:59 +0530

On Sun, Jan 15, 2017 at 08:19:31PM -0600, Benjamin Herrenschmidt wrote:
> The icp-opal call is missing the code from icp-native to recover
> interrupts snatched by KVM. Without that, when running KVM, we can
> get into a situation where an interrupt is lost and the CPU stuck
> with an elevated CPPR.
> 
> Also harden replay by always checking the return from opal_int_eoi
> 
> Signed-off-by: Benjamin Herrenschmidt <[email-masked]>
> ---
>  arch/powerpc/sysdev/xics/icp-opal.c | 31 ++++++++++++++++++++++++-------
>  1 file changed, 24 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/xics/icp-opal.c b/arch/powerpc/sysdev/xics/icp-opal.c
> index d38e86f..60c5765 100644
> --- a/arch/powerpc/sysdev/xics/icp-opal.c
> +++ b/arch/powerpc/sysdev/xics/icp-opal.c
> @@ -20,6 +20,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>

??

<snip>

> @@ -39,7 +40,26 @@ static void icp_opal_flush_ipi(void)
>  	 * Should we be flagging idle loop instead?
>  	 * Or creating some task to be scheduled?
>  	 */
> -	opal_int_eoi((0x00 << 24) | XICS_IPI);
> +	if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0)
> +		force_external_irq_replay();
> +}

Shouldn't we also update kvm bits on icp_native_ipi_action
and icp_native_cause_ipi?

Balbir Singh.