[tip: x86/apic] iommu/amd: Don't register interrupt remapping irqdomain when IR is disabled

[tip-bot2 for David Woodhouse]

The following commit has been merged into the x86/apic branch of tip:

Commit-ID:     2df985f5e44c43f5d29d8cc3aaa8e8ac697e9de6
Gitweb:        https://git.kernel.org/tip/2df985f5e44c43f5d29d8cc3aaa8e8ac697e9de6
Author:        David Woodhouse <dwmw@xxxxxxxxxxxx>
AuthorDate:    Wed, 11 Nov 2020 14:43:20 
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 11 Nov 2020 23:01:58 +01:00

iommu/amd: Don't register interrupt remapping irqdomain when IR is disabled

Registering the remapping irq domain unconditionally is potentially
allowing I/O-APIC and MSI interrupts to be parented in the IOMMU IR domain
even when IR is disabled. Don't do that.

Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20201111144322.1659970-1-dwmw2@xxxxxxxxxxxxx

---
 drivers/iommu/amd/init.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index c2769f2..a94b96f 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1601,9 +1601,11 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 	if (ret)
 		return ret;
 
-	ret = amd_iommu_create_irq_domain(iommu);
-	if (ret)
-		return ret;
+	if (amd_iommu_irq_remap) {
+		ret = amd_iommu_create_irq_domain(iommu);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * Make sure IOMMU is not considered to translate itself. The IVRS