Commit 0f5432a9 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Omit devTLB invalidation requests when TES=0 



The latest VT-d spec indicates that when remapping hardware is disabled
(TES=0 in Global Status Register), upstream ATS Invalidation Completion
requests are treated as UR (Unsupported Request).

Consequently, the spec recommends in section 4.3 Handling of Device-TLB
Invalidations that software refrain from submitting any Device-TLB
invalidation requests when address remapping hardware is disabled.

Verify address remapping hardware is enabled prior to submitting Device-
TLB invalidation requests.

Fixes: 792fb43c ("iommu/vt-d: Enable Intel IOMMU scalable mode by default")
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20231114011036.70142-2-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent e645c20e

drivers/iommu/intel/dmar.c

+18 −0
Original line number Diff line number Diff line
@@ -1522,6 +1522,15 @@ void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid, 
{

	struct qi_desc desc;



	/*

	 * VT-d spec, section 4.3:

	 *

	 * Software is recommended to not submit any Device-TLB invalidation

	 * requests while address remapping hardware is disabled.

	 */

	if (!(iommu->gcmd & DMA_GCMD_TE))

		return;



	if (mask) {

		addr |= (1ULL << (VTD_PAGE_SHIFT + mask - 1)) - 1;

		desc.qw1 = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
@@ -1587,6 +1596,15 @@ void qi_flush_dev_iotlb_pasid(struct intel_iommu *iommu, u16 sid, u16 pfsid, 
	unsigned long mask = 1UL << (VTD_PAGE_SHIFT + size_order - 1);

	struct qi_desc desc = {.qw1 = 0, .qw2 = 0, .qw3 = 0};



	/*

	 * VT-d spec, section 4.3:

	 *

	 * Software is recommended to not submit any Device-TLB invalidation

	 * requests while address remapping hardware is disabled.

	 */

	if (!(iommu->gcmd & DMA_GCMD_TE))

		return;



	desc.qw0 = QI_DEV_EIOTLB_PASID(pasid) | QI_DEV_EIOTLB_SID(sid) |

		QI_DEV_EIOTLB_QDEP(qdep) | QI_DEIOTLB_TYPE |

		QI_DEV_IOTLB_PFSID(pfsid);