[PATCH v6 4/7] iommu/vt-d: Handle RMRR with PCI bridge device scopes

From: Eric Auger <eric.auger@redhat.com>
To: eric.auger.pro@gmail.com, eric.auger@redhat.com, joro@8bytes.org,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	dwmw2@infradead.org, robin.murphy@arm.com
Cc: alex.williamson@redhat.com, shameerali.kolothum.thodi@huawei.com,
	jean-philippe.brucker@arm.com
Subject: [PATCH v6 4/7] iommu/vt-d: Handle RMRR with PCI bridge device scopes
Date: Mon,  3 Jun 2019 08:53:33 +0200	[thread overview]
Message-ID: <20190603065336.10524-5-eric.auger@redhat.com> (raw)
In-Reply-To: <20190603065336.10524-1-eric.auger@redhat.com>

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>

---

v5 -> v6:
- added Lu's R-b

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 bcef10328879..346103ce16d3 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

