Re: [PATCH v4 03/19] hw/arm/smmuv3: Fix encoding of CLASS in events

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

On Mon, Jul 01, 2024 at 11:02:25AM +0000, Mostafa Saleh wrote:
> The SMMUv3 spec (ARM IHI 0070 F.b - 7.3 Event records) defines the
> class of events faults as:
> 
> CLASS: The class of the operation that caused the fault:
> - 0b00: CD, CD fetch.
> - 0b01: TTD, Stage 1 translation table fetch.
> - 0b10: IN, Input address
> 
> However, this value was not set and left as 0 which means CD and not
> IN (0b10).
> While at it, add an enum for class as it would be used for nesting.
> However, at the moment stage-1 and stage-2 use the same class values.
> 
> Fixes: 9bde7f0674 “hw/arm/smmuv3: Implement translate callback”
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> ---
>  hw/arm/smmuv3-internal.h | 6 ++++++
>  hw/arm/smmuv3.c          | 6 +++++-
>  2 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/arm/smmuv3-internal.h b/hw/arm/smmuv3-internal.h
> index e4dd11e1e6..0f3ecec804 100644
> --- a/hw/arm/smmuv3-internal.h
> +++ b/hw/arm/smmuv3-internal.h
> @@ -32,6 +32,12 @@ typedef enum SMMUTranslationStatus {
>      SMMU_TRANS_SUCCESS,
>  } SMMUTranslationStatus;
>  
> +typedef enum SMMUTranslationClass {
> +    SMMU_CLASS_CD,
> +    SMMU_CLASS_TT,
> +    SMMU_CLASS_IN,
> +} SMMUTranslationClass;
> +
>  /* MMIO Registers */
>  
>  REG32(IDR0,                0x0)
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index 9dd3ea48e4..1eb5b160d2 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -942,7 +942,7 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>              event.type = SMMU_EVT_F_WALK_EABT;
>              event.u.f_walk_eabt.addr = addr;
>              event.u.f_walk_eabt.rnw = flag & 0x1;
> -            event.u.f_walk_eabt.class = 0x1;
> +            event.u.f_walk_eabt.class = SMMU_CLASS_TT;

For EABT I think we have to differentiate S1/S2:

* s1-only walk that encounters EABT on S1 descriptor access is reported as
  class=TT, 
* s2 walk that encounters EABT on S2 descriptor while translating
  non-descriptor IPA is reported as class=IN, even when doing s2-only.

Maybe it can be done in the later patch where you propagate the different
classes, because it's a minor detail.

Thanks,
Jean

>              event.u.f_walk_eabt.addr2 = ptw_info.addr;
>              break;
>          case SMMU_PTW_ERR_TRANSLATION:
> @@ -950,6 +950,7 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>                  event.type = SMMU_EVT_F_TRANSLATION;
>                  event.u.f_translation.addr = addr;
>                  event.u.f_translation.addr2 = ptw_info.addr;
> +                event.u.f_translation.class = SMMU_CLASS_IN;
>                  event.u.f_translation.rnw = flag & 0x1;
>              }
>              break;
> @@ -958,6 +959,7 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>                  event.type = SMMU_EVT_F_ADDR_SIZE;
>                  event.u.f_addr_size.addr = addr;
>                  event.u.f_addr_size.addr2 = ptw_info.addr;
> +                event.u.f_translation.class = SMMU_CLASS_IN;
>                  event.u.f_addr_size.rnw = flag & 0x1;
>              }
>              break;
> @@ -966,6 +968,7 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>                  event.type = SMMU_EVT_F_ACCESS;
>                  event.u.f_access.addr = addr;
>                  event.u.f_access.addr2 = ptw_info.addr;
> +                event.u.f_translation.class = SMMU_CLASS_IN;
>                  event.u.f_access.rnw = flag & 0x1;
>              }
>              break;
> @@ -974,6 +977,7 @@ static IOMMUTLBEntry smmuv3_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>                  event.type = SMMU_EVT_F_PERMISSION;
>                  event.u.f_permission.addr = addr;
>                  event.u.f_permission.addr2 = ptw_info.addr;
> +                event.u.f_translation.class = SMMU_CLASS_IN;
>                  event.u.f_permission.rnw = flag & 0x1;
>              }
>              break;
> -- 
> 2.45.2.803.g4e1b14247a-goog
>