Hi Eric,
> -----Original Message-----
> From: Eric Auger <[email protected]>
> Sent: 27 October 2025 18:15
> To: Shameer Kolothum <[email protected]>; qemu-
> [email protected]; [email protected]
> Cc: [email protected]; Jason Gunthorpe <[email protected]>; Nicolin
> Chen <[email protected]>; [email protected]; [email protected];
> Nathan Chen <[email protected]>; Matt Ochs <[email protected]>;
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]
> Subject: Re: [PATCH v4 27/27] hw.arm/smmuv3: Add support for PASID
> enable
>
> External email: Use caution opening links or attachments
>
>
> Hi Shameer,
[..]
> > - if (STE_S1CDMAX(ste) != 0) {
> > + /* If pasid enabled, we report SSIDSIZE = 16 */
> why do we chose 16 and not a bigger value to avoid incompatibility?
> worth a comment
I am not sure what a good value here to support most hardware out there.
If we select a bigger value, anything less can't be supported.
> > + if (!FIELD_EX32(s->idr[1], IDR1, SSIDSIZE) && STE_S1CDMAX(ste) !=
> > + 0) {
> > qemu_log_mask(LOG_UNIMP,
> > "SMMUv3 does not support multiple context descriptors
> yet\n");
> > goto bad_ste;
> > @@ -1962,6 +1963,10 @@ static bool
> smmu_validate_property(SMMUv3State *s, Error **errp)
> > error_setg(errp, "oas can only be set to 44 bits if accel=off");
> > return false;
> > }
> > + if (s->pasid) {
> > + error_setg(errp, "pasid can only be enabled if accel=on");
> > + return false;
> > + }
> > return true;
> > }
> Just skimming though the SMMU spec, I don't see any handling for STE.S1DSS
> anywhere Also I would expect some C_BAD_SUBSTREAMID likely to be
> emitted?
S1DSS is passed down to host kernel during S1 translate HWPT install. And if
anything is mis configured w.r.t CD by Guest, the host SMMUv3 will generate
the events.
Do we need to check S1DSS in here?
Thanks,
Shameer
