This is a note to let you know that I've just added the patch titled
iommu/vt-d: Omit devTLB invalidation requests when TES=0
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-omit-devtlb-invalidation-requests-when-te.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 2a1e4be64f281854850d6a48fb04a565ca5a7687
Author: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Date: Wed Nov 22 11:26:03 2023 +0800
iommu/vt-d: Omit devTLB invalidation requests when TES=0
[ Upstream commit 0f5432a9b839847dcfe9fa369d72e3d646102ddf ]
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: 792fb43ce2c9 ("iommu/vt-d: Enable Intel IOMMU scalable mode by default")
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Link: https://lore.kernel.org/r/20231114011036.70142-2-baolu.lu@xxxxxxxxxxxxxxx
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index f800989ea0462..418af1db0192d 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1495,6 +1495,15 @@ 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;
@@ -1560,6 +1569,15 @@ 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);
