Re: [Qemu-arm] [PATCH for-3.1] target/arm: Remove antique TODO comment

[Philippe Mathieu-Daudé]

On Tue, Nov 6, 2018 at 5:41 PM Peter Maydell <address@hidden> wrote:
>
> Remove a TODO comment about implementing the vectored interrupt
> controller. We have had an implementation of that for a decade;
> it's in hw/intc/pl190.c.
>
> Signed-off-by: Peter Maydell <address@hidden>

On Fri, Nov 9, 2018 at 2:49 PM Peter Maydell <address@hidden> wrote:
>
> Currently we track the state of the four irq lines from the GIC
> only via the cs->interrupt_request or KVM irq state. That means
> that we assume that an interrupt is asserted if and only if the
> external line is set. This assumption is incorrect for VIRQ
> and VFIQ, because the HCR_EL2.{VI,VF} bits allow assertion
> of VIRQ and VFIQ separately from the state of the external line.
>
> To handle this, start tracking the state of the external lines
> explicitly in a CPU state struct field, as is common practice
> for devices.
>
> The complicated part of this is dealing with inbound migration
> from an older QEMU which didn't have this state. We assume in
> that case that the older QEMU did not implement the HCR_EL2.{VI,VF}
> bits as generating interrupts, and so the line state matches
> the current state in cs->interrupt_request. (This is not quite
> true between commit 8a0fc3a29fc2315325400c7 and its revert, but
> that commit is broken and never made it into any released QEMU
> version.)
>
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> ---
>  target/arm/helper.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index ec56becc394..851ea9aa977 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -8378,7 +8378,6 @@ static void arm_cpu_do_interrupt_aarch32(CPUState *cs)
>          return;
>      }
>
> -    /* TODO: Vectored interrupt controller.  */
>      switch (cs->exception_index) {
>      case EXCP_UDEF:
>          new_mode = ARM_CPU_MODE_UND;
> --
> 2.19.1
>
>