Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v1 14/14] iommu/arm-smmu-v3: Add arm_smmu_cache_invalidate_user | Date | Tue, 28 Mar 2023 03:03:11 +0000 |
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> From: Nicolin Chen <nicolinc@nvidia.com> > Sent: Saturday, March 25, 2023 1:35 AM > > On Fri, Mar 24, 2023 at 11:57:09AM -0300, Jason Gunthorpe wrote: > > > > If you suggest to overlay the main cmdq with the vcmdq and then don't > > tell the guest about it.. Robin suggested something similar.
yes, that's my point.
> > Yea, I remember that too, from the email that I received from > Robin on Christmas Eve :) > > Yet, I haven't got a chance to run some experiment with that. > > > This idea would be a half and half, the HW would run the queue and the > > doorbell and generate error interrupts back to the hypervisor and tell > > it that the queue is paused and ask it to fix the failed entry and > > restart. > > > > I could see this as an interesting solution, but I don't know if this > > HW can support it.. > > It possibly can, since an unsupported command will trigger an > Illegal Command interrupt, then the IRQ handler could read it > out of the CMDQ. Again, I'd need to run some experiment, once > this SMMU nesting series is settled down to certain level. >
also you want to ensure that error is a recoverable type so once sw fixes it the hw can continue to behave correctly.
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