On 31/07/2016 16:18, Peter Xu wrote:
> For level triggered interrupts, we will get Remote IRR bit cleared after
> guest kernel finished processing specific request. Before that, we
> should ignore the same interrupt from triggering again.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
> ---
>
> I discovered this during debugging some IR issues. Only did very
> minimum test with e1000, but IIUC this should be the correct behavior
> for level triggered interrupts, and before that we might be sending
> some extra interrupts to guest (while we should not).
>
> hw/intc/ioapic.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
> index 2d3282a..350f761 100644
> --- a/hw/intc/ioapic.c
> +++ b/hw/intc/ioapic.c
> @@ -129,9 +129,15 @@ static void ioapic_service(IOAPICCommonState *s)
> }
> continue;
> }
> -#else
> - (void)coalesce;
> #endif
> +
> + if (coalesce) {
> + /* We are level triggered interrupts, and the
> + * guest should be still working on previous one,
> + * so skip it. */
> + continue;
> + }
> +
> /* No matter whether IR is enabled, we translate
> * the IOAPIC message into a MSI one, and its
> * address space will decide whether we need a
>
The patch is okay for 2.7, as it matches what is done in the KVM
split-irqchip case.
Paolo
