Re: [PATCH v2 09/20] amd_iommu: Add basic structure to support IOMMU notifier updates

[Sairaj Kodilkar <sarunkod@amd.com>]

On 5/2/2025 7:45 AM, Alejandro Jimenez wrote:
> Add the minimal data structures required to maintain a list of address
> spaces (i.e. devices) with registered notifiers, and to update the type of
> events that require notifications.
> Note that the ability to register for MAP notifications is not available.
> It will be unblocked by following changes that enable the synchronization of
> guest I/O page tables with host IOMMU state, at which point an amd-iommu
> device property will be introduced to control this capability.
> 
> Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
> ---
>   hw/i386/amd_iommu.c | 26 +++++++++++++++++++++++---
>   hw/i386/amd_iommu.h |  3 +++
>   2 files changed, 26 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> index 6a2ba878dfa7..2f69459ab68d 100644
> --- a/hw/i386/amd_iommu.c
> +++ b/hw/i386/amd_iommu.c
> @@ -66,6 +66,11 @@ struct AMDVIAddressSpace {
>       MemoryRegion iommu_nodma;   /* Alias of shared nodma memory region  */
>       MemoryRegion iommu_ir;      /* Device's interrupt remapping region  */
>       AddressSpace as;            /* device's corresponding address space */
> +
> +    /* DMA address translation support */
> +    IOMMUNotifierFlag notifier_flags;
> +    /* entry in list of Address spaces with registered notifiers */
> +    QLIST_ENTRY(AMDVIAddressSpace) next;
>   };
>   
>   /* AMDVI cache entry */
> @@ -1711,6 +1716,7 @@ static AddressSpace *amdvi_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>           iommu_as[devfn]->bus_num = (uint8_t)bus_num;
>           iommu_as[devfn]->devfn = (uint8_t)devfn;
>           iommu_as[devfn]->iommu_state = s;
> +        iommu_as[devfn]->notifier_flags = IOMMU_NONE;

Hey
Use IOMMU_NOTIFIER_NONE instead of IOMMU_NONE. Though both are same, the 
clang compiler complains about it and fails to compile (GCC works ok).

Thanks
Sairaj Kodilkar