Re: [PATCH 2/2] hw/arm/smmu-common: Create virtual function for implementation defined StreamID

[Eric Auger <eric.auger@redhat.com>]

Hi,

On 2/21/24 18:17, Nabih Estefan wrote:
> From: Roque Arcudia Hernandez <roqueh@google.com>
>
> According to the SMMU specification the StreamID construction and size is
> IMPLEMENTATION DEFINED, the size being between 0 and 32 bits.
>
> This patch creates virtual functions get_sid and get_iommu_mr to allow different
> implementations of how the StreamID is constructed via inheritance. The default
> implementation of these functions will match the current ones where the BDF is
> used directly as StreamID.

The patch itself looks good to me but it lacks a concrete derived
implementation of get_sid() and get_iommu_mr(). Until you do not
upstream it I don't see the point in introducing those callbacks. Thanks
Eric
>
> Signed-off-by: Roque Arcudia Hernandez <roqueh@google.com>
> Signed-off-by: Nabih Estefan <nabihestefan@google.com>
> ---
>  hw/arm/smmu-common.c         | 12 ++++++++++++
>  include/hw/arm/smmu-common.h | 16 +++++++++++-----
>  2 files changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
> index 4caedb4998..14b3240a88 100644
> --- a/hw/arm/smmu-common.c
> +++ b/hw/arm/smmu-common.c
> @@ -621,6 +621,11 @@ static const PCIIOMMUOps smmu_ops = {
>  };
>  
>  IOMMUMemoryRegion *smmu_iommu_mr(SMMUState *s, uint32_t sid)
> +{
> +    return ARM_SMMU_GET_CLASS(s)->get_iommu_mr(s, sid);
> +}
> +
> +static IOMMUMemoryRegion *smmu_base_iommu_mr(SMMUState *s, uint32_t sid)
>  {
>      uint8_t bus_n, devfn;
>      SMMUPciBus *smmu_bus;
> @@ -659,6 +664,11 @@ void smmu_inv_notifiers_all(SMMUState *s)
>      }
>  }
>  
> +static uint32_t smmu_base_get_sid(SMMUDevice *sdev)
> +{
> +    return PCI_BUILD_BDF(pci_bus_num(sdev->bus), sdev->devfn);
> +}
> +
>  static void smmu_base_realize(DeviceState *dev, Error **errp)
>  {
>      SMMUState *s = ARM_SMMU(dev);
> @@ -709,6 +719,8 @@ static void smmu_base_class_init(ObjectClass *klass, void *data)
>      device_class_set_parent_realize(dc, smmu_base_realize,
>                                      &sbc->parent_realize);
>      rc->phases.hold = smmu_base_reset_hold;
> +    sbc->get_sid = smmu_base_get_sid;
> +    sbc->get_iommu_mr = smmu_base_iommu_mr;
>  }
>  
>  static const TypeInfo smmu_base_info = {
> diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
> index 5ec2e6c1a4..d53121fe37 100644
> --- a/include/hw/arm/smmu-common.h
> +++ b/include/hw/arm/smmu-common.h
> @@ -131,6 +131,9 @@ typedef struct SMMUIOTLBKey {
>      uint8_t level;
>  } SMMUIOTLBKey;
>  
> +#define TYPE_ARM_SMMU "arm-smmu"
> +OBJECT_DECLARE_TYPE(SMMUState, SMMUBaseClass, ARM_SMMU)
> +
>  struct SMMUState {
>      /* <private> */
>      SysBusDevice  dev;
> @@ -147,6 +150,9 @@ struct SMMUState {
>      PCIBus *primary_bus;
>  };
>  
> +typedef uint32_t GetSidFunc(SMMUDevice *obj);
> +typedef IOMMUMemoryRegion *GetIommuMr(SMMUState *s, uint32_t sid);
> +
>  struct SMMUBaseClass {
>      /* <private> */
>      SysBusDeviceClass parent_class;
> @@ -154,19 +160,19 @@ struct SMMUBaseClass {
>      /*< public >*/
>  
>      DeviceRealize parent_realize;
> +    GetSidFunc *get_sid;
> +    GetIommuMr *get_iommu_mr;
>  
>  };
>  
> -#define TYPE_ARM_SMMU "arm-smmu"
> -OBJECT_DECLARE_TYPE(SMMUState, SMMUBaseClass, ARM_SMMU)
> -
>  /* Return the SMMUPciBus handle associated to a PCI bus number */
>  SMMUPciBus *smmu_find_smmu_pcibus(SMMUState *s, uint8_t bus_num);
>  
>  /* Return the stream ID of an SMMU device */
> -static inline uint16_t smmu_get_sid(SMMUDevice *sdev)
> +static inline uint32_t smmu_get_sid(SMMUDevice *sdev)
>  {
> -    return PCI_BUILD_BDF(pci_bus_num(sdev->bus), sdev->devfn);
> +    SMMUState *s = sdev->smmu;
> +    return ARM_SMMU_GET_CLASS(s)->get_sid(sdev);
>  }
>  
>  /**