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SubjectRe: [PATCH 0/2] iommu/vt-d: Select PCI_PRI for INTEL_IOMMU_SVM
On Wed Oct 09 19, Bjorn Helgaas wrote:
>From: Bjorn Helgaas <>
>I think intel-iommu.c depends on CONFIG_AMD_IOMMU in an undesirable way:
>When CONFIG_INTEL_IOMMU_SVM=y, iommu_enable_dev_iotlb() calls PRI
>interfaces (pci_reset_pri() and pci_enable_pri()), but those are only
>implemented when CONFIG_PCI_PRI is enabled. If CONFIG_PCI_PRI is not
>enabled, there are stubs that just return failure.
>The INTEL_IOMMU_SVM Kconfig does nothing with PCI_PRI, but AMD_IOMMU
>selects PCI_PRI. So if AMD_IOMMU is enabled, intel-iommu.c gets the full
>PRI interfaces. If AMD_IOMMU is not enabled, it gets the PRI stubs.
>This seems wrong. The first patch here makes INTEL_IOMMU_SVM select
>PCI_PRI so intel-iommu.c always gets the full PRI interfaces.
>The second patch moves pci_prg_resp_pasid_required(), which simply returns
>a bit from the PCI capability, from #ifdef CONFIG_PCI_PASID to #ifdef
>CONFIG_PCI_PRI. This is related because INTEL_IOMMU_SVM already *does*
>select PCI_PASID, so it previously always got pci_prg_resp_pasid_required()
>even though it got stubs for other PRI things.
>Since these are related and I have several follow-on ATS-related patches in
>the queue, I'd like to take these both via the PCI tree.
>Bjorn Helgaas (2):
> iommu/vt-d: Select PCI_PRI for INTEL_IOMMU_SVM
> PCI/ATS: Move pci_prg_resp_pasid_required() to CONFIG_PCI_PRI
> drivers/iommu/Kconfig | 1 +
> drivers/pci/ats.c | 55 +++++++++++++++++++----------------------
> include/linux/pci-ats.h | 11 ++++-----
> 3 files changed, 31 insertions(+), 36 deletions(-)
>iommu mailing list

Reviewed-by: Jerry Snitselaar <>

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