From: Eric Auger <eric.auger@redhat.com>
Date: Mon, 3 Jun 2019 06:53:33 +0000 (+0200)
Subject: iommu/vt-d: Handle RMRR with PCI bridge device scopes
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e143fd4598ddf7401d3699957cd59ceb5426d53d;p=openwrt%2Fstaging%2Fblogic.git

iommu/vt-d: Handle RMRR with PCI bridge device scopes

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@redhat.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6747fec46cfb..0d7d177673dd 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2880,7 +2880,8 @@ 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;
 			}