Re: [Qemu-devel] [PATCH 07/11] spapr: add hotplug interrupt machine options

[Bharata B Rao]

On Wed, Oct 12, 2016 at 06:13:55PM -0500, Michael Roth wrote:
> This adds machine options of the form:
> 
>   -machine pseries,legacy-hotplug-events=true
>   -machine pseries,legacy-hotplug-events=false
> 
> to denote whether or not we wish to force the use of "legacy" style
> hotplug events, which are surfaced through EPOW interrupts instead of
> a dedicated interrupt source, and lack certain features necessary,
> mainly, for memory unplug support.
> 
> If false, QEMU will default to "legacy" style unless the guest
> advertises support for the newer events via
> ibm,client-architecture-support hcall during early boot.
> 
> For pseries-2.7 and earlier we default to true, for newer machine
> types we default to false.
> 
> Signed-off-by: Michael Roth <address@hidden>
> ---
>  hw/ppc/spapr.c              | 31 +++++++++++++++++++++++++++++++
>  include/hw/ppc/spapr.h      |  1 +
>  include/hw/ppc/spapr_ovec.h |  1 +
>  3 files changed, 33 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index f8cde92..d80a6fa 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1816,6 +1816,11 @@ static void ppc_spapr_init(MachineState *machine)
> 
>      spapr_ovec_set(spapr->ov5, OV5_FORM1_AFFINITY);
> 
> +    /* use dedicated HP event source if guest supports it */
> +    if (spapr->use_hotplug_event_source) {
> +        spapr_ovec_set(spapr->ov5, OV5_HP_EVT);

The above comment can be confusing. Here you really mean that
the machine type version supports OV5_HP_EVT right ? Because
guest support for the same is determined during cas call later.

Regards,
Bharata.