[RFC PATCH v5 2/5] iommu: Set IOMMU_GROUP_CAP_ISOLATE_MSIX if MSI controller enables IRQ remapping

[Alexey Kardashevskiy]

This sets IOMMU_GROUP_CAP_ISOLATE_MSIX to a group if MSI remapping is
enabled on an IRQ domain; this is expected to set the capability
on ARM.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 drivers/iommu/iommu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6b2c34fe2c3d..e720e90fa93c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -32,6 +32,7 @@
 #include <linux/pci.h>
 #include <linux/bitops.h>
 #include <linux/property.h>
+#include <linux/irqdomain.h>
 #include <trace/events/iommu.h>
 
 static struct kset *iommu_group_kset;
@@ -1028,6 +1029,7 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 	struct iommu_group *group;
 	int ret;
+	struct irq_domain *d = dev_get_msi_domain(dev);
 
 	group = iommu_group_get(dev);
 	if (group)
@@ -1070,6 +1072,11 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
 		return ERR_PTR(ret);
 	}
 
+	if (d && irq_domain_is_msi(d) &&
+			irq_domain_hierarchical_is_msi_remap(d))
+		iommu_group_set_caps(group, 0,
+				IOMMU_GROUP_CAP_ISOLATE_MSIX);
+
 	return group;
 }
 
-- 
2.11.0