Commit <4f1492efb495> ("iommu/vt-d: Revert ATS timing change to fix boot failure") placed the enabling of ATS in the probe_finalize callback. This occurs after the default domain attachment, which is when the ATS cache tag is assigned. Consequently, the device TLB cache tag is missed when the domain is attached, leading to the device TLB not being invalidated in the iommu_unmap paths.

Fix this by assigning the CACHE_TAG_DEVTLB cache tag when ATS is enabled.

Fixes: 4f1492efb495 ("iommu/vt-d: Revert ATS timing change to fix boot failure") Cc: stable@vger.kernel.org Suggested-by: Kevin Tian kevin.tian@intel.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Tested-by: Shuicheng Lin shuicheng.lin@intel.com --- drivers/iommu/intel/cache.c | 5 ++--- drivers/iommu/intel/iommu.c | 11 ++++++++++- drivers/iommu/intel/iommu.h | 2 ++ 3 files changed, 14 insertions(+), 4 deletions(-)

Change log: v2: - The v1 solution has a flaw: ATS will never be enabled for drivers with driver_managed_dma enabled, as their devices are not expected to be automatically attached to the default domain.

v1: https://lore.kernel.org/linux-iommu/20250620060802.3036137-1-baolu.lu@linux....

diff --git a/drivers/iommu/intel/cache.c b/drivers/iommu/intel/cache.c index fc35cba59145..47692cbfaabd 100644 --- a/drivers/iommu/intel/cache.c +++ b/drivers/iommu/intel/cache.c @@ -40,9 +40,8 @@ static bool cache_tage_match(struct cache_tag *tag, u16 domain_id, }

/* Assign a cache tag with specified type to domain. */ -static int cache_tag_assign(struct dmar_domain *domain, u16 did, - struct device *dev, ioasid_t pasid, - enum cache_tag_type type) +int cache_tag_assign(struct dmar_domain *domain, u16 did, struct device *dev, + ioasid_t pasid, enum cache_tag_type type) { struct device_domain_info *info = dev_iommu_priv_get(dev); struct intel_iommu *iommu = info->iommu; diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 7aa3932251b2..148b944143b8 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -3780,8 +3780,17 @@ static void intel_iommu_probe_finalize(struct device *dev) !pci_enable_pasid(to_pci_dev(dev), info->pasid_supported & ~1)) info->pasid_enabled = 1;

- if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) + if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) { iommu_enable_pci_ats(info); + /* Assign a DEVTLB cache tag to the default domain. */ + if (info->ats_enabled && info->domain) { + u16 did = domain_id_iommu(info->domain, iommu); + + if (cache_tag_assign(info->domain, did, dev, + IOMMU_NO_PASID, CACHE_TAG_DEVTLB)) + iommu_disable_pci_ats(info); + } + } iommu_enable_pci_pri(info); }

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 3ddbcc603de2..2d1afab5eedc 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -1289,6 +1289,8 @@ struct cache_tag { unsigned int users; };

+int cache_tag_assign(struct dmar_domain *domain, u16 did, struct device *dev, + ioasid_t pasid, enum cache_tag_type type); int cache_tag_assign_domain(struct dmar_domain *domain, struct device *dev, ioasid_t pasid); void cache_tag_unassign_domain(struct dmar_domain *domain,