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

[Nicolin Chen]

On Mon, Jan 13, 2025 at 03:06:41PM -0400, Jason Gunthorpe wrote:
> 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

This is copied from the invalidate union though... Any reason why
this is no longer good for evt v.s. cmd?

> >  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]);

I will use this.

Thanks!
Nicolin