Messages in this thread | | | Date | Wed, 29 Nov 2023 16:28:51 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 4/5] iommu/vt-d: Add support for static identity domain |
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On Wed, Nov 29, 2023 at 04:26:15PM -0400, Jason Gunthorpe wrote: > On Mon, Nov 20, 2023 at 07:29:43PM +0800, Lu Baolu wrote: > > > @@ -2311,6 +2316,13 @@ static int device_def_domain_type(struct device *dev) > > return IOMMU_DOMAIN_IDENTITY; > > } > > > > + /* > > + * Hardware does not support the passthrough translation mode. > > + * Always use a dynamaic mapping domain. > > + */ > > + if (!ecap_pass_through(iommu->ecap)) > > + return IOMMU_DOMAIN_DMA; > > + > > Doesn't this return from def_domain_type completely prevent using an > identity domain? > > I thought the point of this was to allow the identity domain but have > it be translating?
I suppose the answer is the next patch deletes that stuff.
I would probably have structured this in the other order, first add this hunk and say that old HW is being de-supported. Remove all the now-dead code creating the 1:1 page table, then refactor the remainder to create the global static.
Jason
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