This is a note to let you know that I've just added the patch titled iommu/vt-d: Disable PCI ATS in legacy passthrough mode to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iommu-vt-d-disable-pci-ats-in-legacy-passthrough-mod.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c77bc80790d78b3019d3adde7f596ac088b1988c Author: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Date: Wed Nov 22 11:26:04 2023 +0800 iommu/vt-d: Disable PCI ATS in legacy passthrough mode [ Upstream commit da37dddcf4caf015c400a930301d2ee27a7a15fb ] When IOMMU hardware operates in legacy mode, the TT field of the context entry determines the translation type, with three supported types (Section 9.3 Context Entry): - DMA translation without device TLB support - DMA translation with device TLB support - Passthrough mode with translated and translation requests blocked Device TLB support is absent when hardware is configured in passthrough mode. Disable the PCI ATS feature when IOMMU is configured for passthrough translation type in legacy (non-scalable) mode. Fixes: 0faa19a1515f ("iommu/vt-d: Decouple PASID & PRI enabling from SVA") Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> Link: https://lore.kernel.org/r/20231114011036.70142-3-baolu.lu@xxxxxxxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index de76272d0fb02..807abf4707be7 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2517,7 +2517,8 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev) return ret; } - iommu_enable_pci_caps(info); + if (sm_supported(info->iommu) || !domain_type_is_si(info->domain)) + iommu_enable_pci_caps(info); return 0; }