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iommu/vt-d: Require DMA domain if hardware not support passthrough

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The iommu core defines the def_domain_type callback to query the iommu
driver about hardware capability and quirks. The iommu driver should
declare IOMMU_DOMAIN_DMA requirement for hardware lacking pass-through
capability.

Earlier VT-d hardware implementations did not support pass-through
translation mode. The iommu driver relied on a paging domain with all
physical system memory addresses identically mapped to the same IOVA
to simulate pass-through translation before the def_domain_type was
introduced and it has been kept until now. It's time to adjust it now
to make the Intel iommu driver follow the def_domain_type semantics.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20240809055431.36513-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu
2024-09-02 10:27:11 +08:00
committed by Joerg Roedel
parent 7c626ce4ba
commit 184bee388d
1 changed files with 10 additions and 0 deletions
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drivers/iommu/intel/iommu.c
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@@ -2149,6 +2149,16 @@ static bool device_rmrr_is_relaxable(struct device *dev)
static int device_def_domain_type(struct device *dev)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
struct intel_iommu *iommu = info->iommu;
/*
* Hardware does not support the passthrough translation mode.
* Always use a dynamaic mapping domain.
*/
if (!ecap_pass_through(iommu->ecap))
return IOMMU_DOMAIN_DMA;
if (dev_is_pci(dev)) {
struct pci_dev *pdev = to_pci_dev(dev);