[PATCH v2 4/7] iommu/vt-d: Handle RMRR with PCI bridge device scopes

From: Eric Auger
Date: Thu May 16 2019 - 04:49:54 EST


When reading the vtd specification and especially the
Reserved Memory Region Reporting Structure chapter,
it is not obvious a device scope element cannot be a
PCI-PCI bridge, in which case all downstream ports are
likely to access the reserved memory region. Let's handle
this case in device_has_rmrr.

Fixes: ea2447f700ca ("intel-iommu: Prevent devices with RMRRs from being placed into SI Domain")

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---

v1 -> v2:
- is_downstream_to_pci_bridge helper introduced in a separate patch
---
drivers/iommu/intel-iommu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 15c2f9677491..7ed820e79313 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2910,7 +2910,8 @@ static bool device_has_rmrr(struct device *dev)
*/
for_each_active_dev_scope(rmrr->devices,
rmrr->devices_cnt, i, tmp)
- if (tmp == dev) {
+ if (tmp == dev ||
+ is_downstream_to_pci_bridge(dev, tmp)) {
rcu_read_unlock();
return true;
}
--
2.20.1