[PATCH 1/2] iommu/vt-d: Make Intel SVM code 64-bit only

From: Lu Baolu
Date: Sun May 31 2020 - 20:48:27 EST


Current Intel SVM is designed by setting the pgd_t of the processor page
table to FLPTR field of the PASID entry. The first level translation only
supports 4 and 5 level paging structures, hence it's infeasible for the
IOMMU to share a processor's page table when it's running in 32-bit mode.
Let's disable 32bit support for now and claim support only when all the
missing pieces are ready in the future.

Fixes: 1c4f88b7f1f92 ("iommu/vt-d: Shared virtual address in scalable mode")
Suggested-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index aca76383f201..e6e0259c0a1c 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -211,7 +211,7 @@ config INTEL_IOMMU_DEBUGFS

config INTEL_IOMMU_SVM
bool "Support for Shared Virtual Memory with Intel IOMMU"
- depends on INTEL_IOMMU && X86
+ depends on INTEL_IOMMU && X86_64
select PCI_PASID
select PCI_PRI
select MMU_NOTIFIER
--
2.17.1