Re: [Qemu-devel] [PATCH] pc: Clean up PIC-to-APIC IRQ path

[Anthony Liguori <aliguori@us.ibm.com>]

On 08/27/2011 09:16 AM, Jan Kiszka wrote:
> From: Jan Kiszka<jan.kiszka@siemens.com>
>
> The master PIC is connected to the LINTIN0 of the APICs. As the APIC
> currently does not track the state of that line, we have to ask the PIC
> to re-inject its IRQ after the CPU picked up an event from the APIC.
>
> Adds the proper state tracking so that we can already re-assert the CPU
> IRQ at APIC level if there is a pending PIC IRQ. This allows to remove
> all the old workarounds.
>
> The patch also fixes some failures of the kvm unit tests apic and
> eventinj by enabling a proper CPU IRQ deassert when the guest masks some
> pending IRQs at PIC level.
>
> Signed-off-by: Jan Kiszka<jan.kiszka@siemens.com>
> ---
>
> It turned out that this patch from a larger cleanup series has no
> dependencies and can be applied directly to master to fix the observed
> bug.
>
>   hw/apic.c  |    4 +++-
>   hw/i8259.c |   10 ++--------
>   hw/pc.c    |    3 ---
>   hw/pc.h    |    1 -
>   4 files changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/hw/apic.c b/hw/apic.c
> index d8f56c8..22ad635 100644
> --- a/hw/apic.c
> +++ b/hw/apic.c
> @@ -104,6 +104,7 @@ struct APICState {
>       QEMUTimer *timer;
>       int sipi_vector;
>       int wait_for_sipi;
> +    int pic_level;
>   };

Does this need to be save/restored for migration?

Regards,

Anthony Liguori