Re: [Qemu-devel] [RFC PATCH v3 09/10] arm_gic: Add GICC_APRn state to the GICState

[Peter Maydell]

On 19 November 2013 06:18, Christoffer Dall <address@hidden> wrote:
> The GICC_APRn registers are not currently supported by the ARM GIC v2.0
> emulation.  This patch adds the missing state.  The state was previously
> added in the main vgic save/restore patch, but moved to a separate patch
> as suggested under review.

Remarks about changes under code review go under the '---';
the commit message should ideally be a freestanding description
of the change.

> Note that we also change the number of APRs to use a define GIC_NR_APRS
> based on the maximum number of preemption levels.  This patch also adds
> RAZ/WI accessors for the four registers on the emulated CPU interface.
>
> Signed-off-by: Christoffer Dall <address@hidden>
> ---
>  hw/intc/arm_gic.c                |  5 +++++
>  hw/intc/arm_gic_common.c         |  5 +++--
>  include/hw/intc/arm_gic_common.h | 11 +++++++++++
>  3 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
> index 20e926c..09f03e6 100644
> --- a/hw/intc/arm_gic.c
> +++ b/hw/intc/arm_gic.c
> @@ -616,6 +616,8 @@ static uint32_t gic_cpu_read(GICState *s, int cpu, int 
> offset)
>          return s->current_pending[cpu];
>      case 0x1c: /* Aliased Binary Point */
>          return s->abpr[cpu];
> +    case 0xd0: case 0xd4: case 0xd8: case 0xdc:
> +        return s->apr[(offset - 0xd0) / 4][cpu];
>      default:
>          qemu_log_mask(LOG_GUEST_ERROR,
>                        "gic_cpu_read: Bad offset %x\n", (int)offset);
> @@ -643,6 +645,9 @@ static void gic_cpu_write(GICState *s, int cpu, int 
> offset, uint32_t value)
>              s->abpr[cpu] = (value & 0x7);
>          }
>          break;
> +    case 0xd0: case 0xd4: case 0xd8: case 0xdc:
> +        DPRINTF("Writing APR not yet supported\n");

qemu_log_mask(LOG_UNIMP, ....);

> +        break;
>      default:
>          qemu_log_mask(LOG_GUEST_ERROR,
>                        "gic_cpu_write: Bad offset %x\n", (int)offset);
> diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
> index 65e3dc8..8dcb4fb 100644
> --- a/hw/intc/arm_gic_common.c
> +++ b/hw/intc/arm_gic_common.c
> @@ -59,8 +59,8 @@ static const VMStateDescription vmstate_gic_irq_state = {
>
>  static const VMStateDescription vmstate_gic = {
>      .name = "arm_gic",
> -    .version_id = 6,
> -    .minimum_version_id = 6,
> +    .version_id = 7,
> +    .minimum_version_id = 7,
>      .pre_save = gic_pre_save,
>      .post_load = gic_post_load,
>      .fields = (VMStateField[]) {
> @@ -79,6 +79,7 @@ static const VMStateDescription vmstate_gic = {
>          VMSTATE_UINT16_ARRAY(current_pending, GICState, GIC_NCPU),
>          VMSTATE_UINT8_ARRAY(bpr, GICState, GIC_NCPU),
>          VMSTATE_UINT8_ARRAY(abpr, GICState, GIC_NCPU),
> +        VMSTATE_UINT32_2DARRAY(apr, GICState, GIC_NR_APRS, GIC_NCPU),
>          VMSTATE_END_OF_LIST()
>      }
>  };
> diff --git a/include/hw/intc/arm_gic_common.h 
> b/include/hw/intc/arm_gic_common.h
> index 2d6c23f..e815593 100644
> --- a/include/hw/intc/arm_gic_common.h
> +++ b/include/hw/intc/arm_gic_common.h
> @@ -31,6 +31,9 @@
>  /* Maximum number of possible CPU interfaces, determined by GIC architecture 
> */
>  #define GIC_NCPU 8
>
> +#define MAX_NR_GROUP_PRIO 128
> +#define GIC_NR_APRS (MAX_NR_GROUP_PRIO / 32)
> +
>  typedef struct gic_irq_state {
>      /* The enable bits are only banked for per-cpu interrupts.  */
>      uint8_t enabled;
> @@ -70,6 +73,14 @@ typedef struct GICState {
>      uint8_t  bpr[GIC_NCPU];
>      uint8_t  abpr[GIC_NCPU];
>
> +    /* The APR is implementation defined, so we choose a layout identical to
> +     * the KVM ABI layout for QEMU's implementation of the gic:
> +     * If an interrupt for preemption level X are active, then

"is active"

> +     *   APRn[X mod 32] == 0b1,  where n = X / 32
> +     * otherwise the bit is clear.
> +     */
> +    uint32_t apr[GIC_NR_APRS][GIC_NCPU];
> +
>      uint32_t num_cpu;
>
>      MemoryRegion iomem; /* Distributor */
> --
> 1.8.4.3

thanks
-- PMM