Re: [RFC PATCH v3 17/18] hw/arm/smmuv3: Add property for OAS

[Eric Auger]

Hi Mostafa,

On 4/29/24 05:24, Mostafa Saleh wrote:
> Add property that sets the OAS of the SMMU, this in not used in this
> patch.
>
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> ---
>  hw/arm/smmuv3-internal.h |  3 ++-
>  hw/arm/smmuv3.c          | 29 ++++++++++++++++++++++++++++-
>  include/hw/arm/smmuv3.h  |  1 +
>  3 files changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/hw/arm/smmuv3-internal.h b/hw/arm/smmuv3-internal.h
> index 0ebf2eebcf..dd91807624 100644
> --- a/hw/arm/smmuv3-internal.h
> +++ b/hw/arm/smmuv3-internal.h
> @@ -111,7 +111,8 @@ REG32(IDR5,                0x14)
>       FIELD(IDR5, VAX,        10, 2);
>       FIELD(IDR5, STALL_MAX,  16, 16);
>  
> -#define SMMU_IDR5_OAS 4
> +#define SMMU_IDR5_OAS_DEF 4 /* 44 bits. */
> +#define SMMU_IDR5_OAS_MAX 5 /* 48 bits. */
>  
>  REG32(IIDR,                0x18)
>  REG32(AIDR,                0x1c)
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index 4ac818cf7a..39d03e7e24 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -299,7 +299,9 @@ static void smmuv3_init_regs(SMMUv3State *s)
>      s->idr[3] = FIELD_DP32(s->idr[3], IDR3, RIL, 1);
>      s->idr[3] = FIELD_DP32(s->idr[3], IDR3, BBML, 2);
>  
> -    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, SMMU_IDR5_OAS); /* 44 bits 
> */
> +    /* PTW doesn't support 52 bits. */
remove the point
> +    s->oas = MIN(s->oas, SMMU_IDR5_OAS_MAX);
> +    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, s->oas);
>      /* 4K, 16K and 64K granule support */
>      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN4K, 1);
>      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN16K, 1);
> @@ -1901,11 +1903,34 @@ static const VMStateDescription vmstate_gbpa = {
>      }
>  };
>  
> +static const VMStateDescription vmstate_oas = {
> +    .name = "smmuv3/oas",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
don't you need a .needed function?

I tested backward migration and this fails
qemu-system-aarch64: error while loading state for instance 0x0 of
device 'smmuv3'
qemu-system-aarch64: load of migration failed: No such file or directory
post-processing ...

Thanks

Eric
> +    .fields = (const VMStateField[]) {
> +        VMSTATE_INT32(oas, SMMUv3State),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static int smmuv3_preload(void *opaque)
> +{
> +    SMMUv3State *s = opaque;
> +
> +    /*
> +     * In case it wasn't migrated, use the value used
> +     * by older QEMU.
> +     */
> +    s->oas = SMMU_IDR5_OAS_DEF;
> +    return 0;
> +}
> +
>  static const VMStateDescription vmstate_smmuv3 = {
>      .name = "smmuv3",
>      .version_id = 1,
>      .minimum_version_id = 1,
>      .priority = MIG_PRI_IOMMU,
> +    .pre_load = smmuv3_preload,
>      .fields = (const VMStateField[]) {
>          VMSTATE_UINT32(features, SMMUv3State),
>          VMSTATE_UINT8(sid_size, SMMUv3State),
> @@ -1933,6 +1958,7 @@ static const VMStateDescription vmstate_smmuv3 = {
>      },
>      .subsections = (const VMStateDescription * const []) {
>          &vmstate_gbpa,
> +        &vmstate_oas,
>          NULL
>      }
>  };
> @@ -1945,6 +1971,7 @@ static Property smmuv3_properties[] = {
>       * Defaults to stage 1
>       */
>      DEFINE_PROP_STRING("stage", SMMUv3State, stage),
> +    DEFINE_PROP_INT32("oas", SMMUv3State, oas, SMMU_IDR5_OAS_DEF),
>      DEFINE_PROP_END_OF_LIST()
>  };
>  
> diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h
> index d183a62766..00a9eb4467 100644
> --- a/include/hw/arm/smmuv3.h
> +++ b/include/hw/arm/smmuv3.h
> @@ -63,6 +63,7 @@ struct SMMUv3State {
>      qemu_irq     irq[4];
>      QemuMutex mutex;
>      char *stage;
> +    int32_t oas;
>  };
>  
>  typedef enum {