The bus number of a PCIe endpoint may change after PCIe re-enumeration,
potentially causing the device ID stored in RISCVIOMMUSpace to become
outdated. This can lead to an incorrect Device Directory Table walk.

This commit ensures that the IOMMU dynamically retrieves the latest device
IDs from the memory attributes of the requester devices, ensuring accuracy.

Signed-off-by: Jason Chien <jason.chien@sifive.com>
---
 hw/riscv/riscv-iommu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/hw/riscv/riscv-iommu.c b/hw/riscv/riscv-iommu.c
index d46beb2d64..b72ce8e6d0 100644
--- a/hw/riscv/riscv-iommu.c
+++ b/hw/riscv/riscv-iommu.c
@@ -2644,7 +2644,13 @@ void riscv_iommu_pci_setup_iommu(RISCVIOMMUState *iommu, PCIBus *bus,
 static int riscv_iommu_memory_region_index(IOMMUMemoryRegion *iommu_mr,
     MemTxAttrs attrs)
 {
-    return attrs.unspecified ? RISCV_IOMMU_NOPROCID : (int)attrs.pid;
+    RISCVIOMMUSpace *as = container_of(iommu_mr, RISCVIOMMUSpace, iova_mr);
+
+    /* Requesters must attach its device ID. */
+    g_assert(attrs.unspecified == 0);
+
+    as->devid = attrs.requester_id;
+    return attrs.pid;
 }
 
 static int riscv_iommu_memory_region_index_len(IOMMUMemoryRegion *iommu_mr)
-- 
2.43.2

On 3/2/25 6:12 AM, Jason Chien wrote:
> The bus number of a PCIe endpoint may change after PCIe re-enumeration,
> potentially causing the device ID stored in RISCVIOMMUSpace to become
> outdated. This can lead to an incorrect Device Directory Table walk.
> 
> This commit ensures that the IOMMU dynamically retrieves the latest device
> IDs from the memory attributes of the requester devices, ensuring accuracy.
> 
> Signed-off-by: Jason Chien <jason.chien@sifive.com>
> ---

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

>   hw/riscv/riscv-iommu.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/riscv/riscv-iommu.c b/hw/riscv/riscv-iommu.c
> index d46beb2d64..b72ce8e6d0 100644
> --- a/hw/riscv/riscv-iommu.c
> +++ b/hw/riscv/riscv-iommu.c
> @@ -2644,7 +2644,13 @@ void riscv_iommu_pci_setup_iommu(RISCVIOMMUState *iommu, PCIBus *bus,
>   static int riscv_iommu_memory_region_index(IOMMUMemoryRegion *iommu_mr,
>       MemTxAttrs attrs)
>   {
> -    return attrs.unspecified ? RISCV_IOMMU_NOPROCID : (int)attrs.pid;
> +    RISCVIOMMUSpace *as = container_of(iommu_mr, RISCVIOMMUSpace, iova_mr);
> +
> +    /* Requesters must attach its device ID. */
> +    g_assert(attrs.unspecified == 0);
> +
> +    as->devid = attrs.requester_id;
> +    return attrs.pid;
>   }
>   
>   static int riscv_iommu_memory_region_index_len(IOMMUMemoryRegion *iommu_mr)