Messages in this thread | | | Subject | Re: [PATCH 4/4] powerpc/pseries/iommu: Remove default DMA window before creating DDW | From | Alexey Kardashevskiy <> | Date | Tue, 23 Jun 2020 13:52:06 +1000 |
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On 23/06/2020 12:43, Leonardo Bras wrote: > On Tue, 2020-06-23 at 12:35 +1000, Alexey Kardashevskiy wrote: >>> I am not sure if this is true in general, but in this device (SR-IOV >>> VF) I am testing it will return 0 windows if the default DMA window is >>> not deleted, and 1 after it's deleted. >> >> Since pHyp can only create windows in "64bit space", now (I did not know >> until a few month back) I expect that thing to return "1" always no >> matter what happened to the default window. And removing the default >> window will only affect the maximum number of TCEs but not the number of >> possible windows. > > Humm, something gone wrong then. > > This patchset was developed mostly because on testing, DDW would never > be created because windows_available would always be 0.
? On phyp, if there is a huge window, then it can be 0 or 1. On KVM, it is 0 or 1 or 2.
> > I will take a deeper look in that. > > Best regards, > Leonardo >
-- Alexey
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