Re: [PATCH v4 5/7] hw/arm/virt: Add an SMMU_IO_LEN macro

[Jonathan Cameron via <qemu-arm@nongnu.org>]

On Fri, 13 Jun 2025 15:44:47 +0100
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:

> From: Nicolin Chen <nicolinc@nvidia.com>
> 
> This is useful as the subsequent support for new SMMUv3 dev will also
> use the same.
> 
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Reviewed-by: Donald Dutile <ddutile@redhat.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Nathan Chen <nathanc@nvidia.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  hw/arm/virt.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 71b923f786..eeace4754d 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -146,6 +146,9 @@ static void arm_virt_compat_set(MachineClass *mc)
>  #define LEGACY_RAMLIMIT_GB 255
>  #define LEGACY_RAMLIMIT_BYTES (LEGACY_RAMLIMIT_GB * GiB)
>  
> +/* MMIO region size for SMMUv3 */
> +#define SMMU_IO_LEN 0x20000
> +
>  /* Addresses and sizes of our components.
>   * 0..128MB is space for a flash device so we can run bootrom code such as UEFI.
>   * 128MB..256MB is used for miscellaneous device I/O.
> @@ -177,7 +180,7 @@ static const MemMapEntry base_memmap[] = {
>      [VIRT_FW_CFG] =             { 0x09020000, 0x00000018 },
>      [VIRT_GPIO] =               { 0x09030000, 0x00001000 },
>      [VIRT_UART1] =              { 0x09040000, 0x00001000 },
> -    [VIRT_SMMU] =               { 0x09050000, 0x00020000 },
> +    [VIRT_SMMU] =               { 0x09050000, SMMU_IO_LEN },

This bit is fine.

>      [VIRT_PCDIMM_ACPI] =        { 0x09070000, MEMORY_HOTPLUG_IO_LEN },
>      [VIRT_ACPI_GED] =           { 0x09080000, ACPI_GED_EVT_SEL_LEN },
>      [VIRT_NVDIMM_ACPI] =        { 0x09090000, NVDIMM_ACPI_IO_LEN},
> @@ -1447,7 +1450,6 @@ static void create_smmu(const VirtMachineState *vms,
>      int irq =  vms->irqmap[VIRT_SMMU];
>      int i;
>      hwaddr base = vms->memmap[VIRT_SMMU].base;
> -    hwaddr size = vms->memmap[VIRT_SMMU].size;
>      DeviceState *dev;
>  
>      if (vms->iommu != VIRT_IOMMU_SMMUV3 || !vms->iommu_phandle) {
> @@ -1467,7 +1469,7 @@ static void create_smmu(const VirtMachineState *vms,
>          sysbus_connect_irq(SYS_BUS_DEVICE(dev), i,
>                             qdev_get_gpio_in(vms->gic, irq + i));
>      }
> -    create_smmuv3_dt_bindings(vms, base, size, irq);
> +    create_smmuv3_dt_bindings(vms, base, SMMU_IO_LEN, irq);

This seems a little odd.  I guess it may make sense later, but for all other
cases we only use the macros to define the base_memmap.

Perhaps delay this change until it is more obvious why?


>  }
>  
>  static void create_virtio_iommu_dt_bindings(VirtMachineState *vms)