[PATCH v2 3/7] iommu/vt-d: Don't enable iommu's which have been ignored

From: Lu Baolu
Date: Tue Jun 11 2019 - 20:41:01 EST


The iommu driver will ignore some iommu units if there's no
device under its scope or those devices have been explicitly
set to bypass the DMA translation. Don't enable those iommu
units, otherwise the devices under its scope won't work.

Fixes: d8190dc638866 ("iommu/vt-d: Enable DMA remapping after rmrr mapped")
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d1a82039e835..5251533a18a4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3232,7 +3232,12 @@ static int __init init_dmars(void)
goto error;
}

- for_each_active_iommu(iommu, drhd) {
+ for_each_iommu(iommu, drhd) {
+ if (drhd->ignored) {
+ iommu_disable_translation(iommu);
+ continue;
+ }
+
/*
* Find the max pasid size of all IOMMU's in the system.
* We need to ensure the system pasid table is no bigger
@@ -4793,7 +4798,7 @@ int __init intel_iommu_init(void)

/* Finally, we enable the DMA remapping hardware. */
for_each_iommu(iommu, drhd) {
- if (!translation_pre_enabled(iommu))
+ if (!drhd->ignored && !translation_pre_enabled(iommu))
iommu_enable_translation(iommu);

iommu_disable_protect_mem_regions(iommu);
--
2.17.1