Re: [PATCH v5 14/14] iommu/arm-smmu-v3: Report events that belong to devices attached to vIOMMU

[Jason Gunthorpe]

On Mon, Jan 13, 2025 at 11:01:10AM -0800, Nicolin Chen wrote:

> +/* This is basically iommu_vevent_arm_smmuv3 in u64 for conversion */
> +struct arm_vsmmu_evt {
> +	union {
> +		u64 evt[EVTQ_ENT_DWORDS];
> +		struct iommu_vevent_arm_smmuv3 uevt;
> +	};
> +};

This doesn't seem right, don't make unions like this

>  int arm_vmaster_report_event(struct arm_smmu_vmaster *vmaster, u64 *evt)
>  {
> -	struct iommu_vevent_arm_smmuv3 vevt =
> -		*(struct iommu_vevent_arm_smmuv3 *)evt;

evt is clearly not a iommu_vevent_arm_smmuv3 since it has the wrong
endianess? It should stay in its own type.

struct struct iommu_vevent_arm_smmuv3 uevt;

uet.evt[0] = cpu_to_le64((evt[0] & ~EVTQ_0_SID) | FIELD_PREP(EVTQ_0_SID, vmaster->vsid));
for (i = 1; i != EVTQ_ENT_DWORDS; i++)
    uet.evt[i] = cpu_to_le64(evt[i]);

Jason