[PATCH 0/2]Add Variable Page Size and IA64 Support in Intel IOMMU

[PATCH 0/2]Add Variable Page Size and IA64 Support in Intel IOMMU

[Fenghua Yu]

The following two patches (Intel IOMMU generic patch and ia64 specific patch) together enable Intel IOMMU on IA64 platform. They are applied cleanly on the latest linux-next tree which contains Intel IOMMU interrupt remapping and VT-d driver KVM support code.

If applying only the generic patch on x86-64 kernel, x86-64 IOMMU is working fine, i.e. the generic patch doesn't have compilation and functionality impact on x86-64 IOMMU. If applying only the ia64 specific patch on ia64 kernel, ia64 is working as non-IOMMU/swiotlb case. If applying both of the patches and set CONFIG_DMAR=y, ia64 IOMMU is working.

Thanks.

-Fenghua

Re: [PATCH 0/2]Add Variable Page Size and IA64 Support in Intel IOMMU

[Bjorn Helgaas]

On Wednesday 01 October 2008 10:56:06 am Fenghua Yu wrote:
> The following two patches (Intel IOMMU generic patch and ia64 specific patch) together enable Intel IOMMU on IA64 platform. They are applied cleanly on the latest linux-next tree which contains Intel IOMMU interrupt remapping and VT-d driver KVM support code.

General comment (not ia64-related): it looks like you detect the
IOMMU using the static DMAR table.  Does the IOMMU also appear in
PCI config space or the ACPI namespace?  I expect it would, because
the fact that the DMAR table is static precludes any sort of hot-plug
to add or remove IOMMUs.

If it *is* in config space or the namespace, it would be good to
exercise that discovery path to help shake out firmware bugs.  For
example, arch/ia64/hp/common/sba_iommu.c uses acpi_bus_register_driver()
to discover HP IOMMUs.  I wouldn't hold the sba_iommu.c discovery code
(most of which I take the blame for) up as a shining example of how to
do things, but it shows the point.

Bjorn

RE: [PATCH 0/2]Add Variable Page Size and IA64 Support in Intel

[Yu, Fenghua]

>> The following two patches (Intel IOMMU generic patch and ia64 specific

>the fact that the DMAR table is static precludes any sort of hot-plug
>to add or remove IOMMUs.

The latest VT-d spec v1.1 does not support hot plug. If the feature is available in newer spec, we will support it.

Thanks.

-Fenghua

[PATCH V2 0/2] Add Variable Page Size and IA64 Support in Intel IOMMU

[Fenghua Yu]

The patche set (Intel IOMMU generic patch and ia64 specific patch) together enable Intel IOMMU on IA64 platform. They are applied cleanly on the latest linux-next tree which contains Intel IOMMU interrupt remapping and VT-d driver KVM support code.
 
If applying only the generic patch on x86-64 kernel, x86-64 IOMMU is working fine, i.e. the generic patch doesn't have compilation and functionality impact on x86-64 IOMMU. If applying only the ia64 specific patch on ia64 kernel, ia64 is working as non-IOMMU/swiotlb case. If applying both of the patches and set CONFIG_DMAR=y, ia64 IOMMU is working.
 
Thanks.
 
-Fenghua