Re: [RFC PATCH v8 13/23] hw/intc/arm_gicv3: Add irq superpriority information

[Peter Maydell]

On Mon, 18 Mar 2024 at 09:38, Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>
> A SPI, PPI or SGI interrupt can have a superpriority property. So
> maintain superpriority information in PendingIrq and GICR/GICD.
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> Acked-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> v3:
> - Place this ahead of implement GICR_INMIR.
> - Add Acked-by.
> ---
>  include/hw/intc/arm_gicv3_common.h | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/include/hw/intc/arm_gicv3_common.h 
> b/include/hw/intc/arm_gicv3_common.h
> index 7324c7d983..df4380141d 100644
> --- a/include/hw/intc/arm_gicv3_common.h
> +++ b/include/hw/intc/arm_gicv3_common.h
> @@ -146,6 +146,7 @@ typedef struct {
>      int irq;
>      uint8_t prio;
>      int grp;
> +    bool superprio;
>  } PendingIrq;
>
>  struct GICv3CPUState {
> @@ -172,6 +173,7 @@ struct GICv3CPUState {
>      uint32_t gicr_ienabler0;
>      uint32_t gicr_ipendr0;
>      uint32_t gicr_iactiver0;
> +    uint32_t gicr_isuperprio;

This field stores the state that is in the GICR_INMIR0
register, so please name it that way: gicr_inmir0.

>      uint32_t edge_trigger; /* ICFGR0 and ICFGR1 even bits */
>      uint32_t gicr_igrpmodr0;
>      uint32_t gicr_nsacr;
> @@ -274,6 +276,7 @@ struct GICv3State {
>      GIC_DECLARE_BITMAP(active);       /* GICD_ISACTIVER */
>      GIC_DECLARE_BITMAP(level);        /* Current level */
>      GIC_DECLARE_BITMAP(edge_trigger); /* GICD_ICFGR even bits */
> +    GIC_DECLARE_BITMAP(superprio);    /* GICD_INMIR */
>      uint8_t gicd_ipriority[GICV3_MAXIRQ];
>      uint64_t gicd_irouter[GICV3_MAXIRQ];
>      /* Cached information: pointer to the cpu i/f for the CPUs specified
> @@ -313,6 +316,7 @@ GICV3_BITMAP_ACCESSORS(pending)
>  GICV3_BITMAP_ACCESSORS(active)
>  GICV3_BITMAP_ACCESSORS(level)
>  GICV3_BITMAP_ACCESSORS(edge_trigger)
> +GICV3_BITMAP_ACCESSORS(superprio)

This is the state behind the GICD_INMIR<n> registers, and
the GIC spec calls the bits in those registers NMI<x>,
so I would call this bitmap nmi, not superprio.

This commit adds new device state, so it also needs to be migrated.
You'll want to add a new subsection to vmstate_gicv3_cpu which
is present if the GIC implements NMIs, and which has an entry
for the gicr_inmir0 field. Similarly, you want a new subsection
in vmstate_gicv3 which is present if NMIs are implemented and which
has a field for the nmi array.

thanks
-- PMM