On Wed, 6 Dec 2023 at 09:30, Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > > On Wed, Dec 06, 2023 at 08:57:27AM +0800, Zhangfei Gao wrote: > > From: Wenkai Lin <linwenkai6@xxxxxxxxxxxxx> > > > > In the stall model, invalid transactions were expected to be > > stalled and aborted by the IOPF handler. > > > > However, when killing a test case with a huge amount of data, the > > accelerator streamline can not stop until all data is consumed > > even if the page fault handler reports errors. As a result, the > > kill may take a long time, about 10 seconds with numerous iopf > > interrupts. > > > > So disable stall for quiet_cd in the non-force stall model, since > > force stall model (STALL_MODEL==0b10) requires CD.S must be 1. > > I think this force-stall thing should get a closer look, it doesn't > look completely implemented and what does it mean for, eg, non-SVA > domains attached to the device (as we now support with S2 and soon > with PASID) > > The manual says: > > 0b10 Stall is forced (all faults eligible to stall cause stall), > STE.S2S and CD.S must be 1. > > And there is a note: > > Note: For faulting transactions that are associated with client > devices that have been configured to stall, but where > the system has not explicitly advertised the client devices to be > usable with the stall model, Arm recommends for > software to expect that events might be recorded with Stall == 0. > > Which makes it seem like it isn't actually "force" per-say, but > something else. > > I notice the driver never sets STE.S2S, and it isn't entirely clear > what software should even do for a standard non-faulting domain where > non-present means failure? Take the fault event and always respond > with failure? What is the purpose? Sorry, I have no idea :) > > Aside from that the change looks OK to me: > > Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Thanks Jason.
