From: Joerg Roedel <jroedel@suse.de>
Date: Wed, 30 Sep 2020 11:50:36 +0200
Subject: [PATCH] iommu/vt-d: Correctly calculate agaw in domain_init()
Patch-mainline: Never, code refactored and bug not present anymore upstream
References: bsc#1176400

The calculation result can not be larger than iommu->agaw.
Account for that and also set domain->gaw correctly.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/intel-iommu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3f099cedaaf3..04bd5e73a7cb 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1863,9 +1863,11 @@ static int domain_init(struct dmar_domain *domain, struct intel_iommu *iommu,
 	/* calculate AGAW */
 	if (guest_width > cap_mgaw(iommu->cap))
 		guest_width = cap_mgaw(iommu->cap);
-	domain->gaw = guest_width;
 	adjust_width = guestwidth_to_adjustwidth(guest_width);
 	agaw = width_to_agaw(adjust_width);
+	if (agaw > iommu->agaw)
+		agaw = iommu->agaw;
+	domain->gaw = agaw_to_width(agaw);
 	sagaw = cap_sagaw(iommu->cap);
 	if (!test_bit(agaw, &sagaw)) {
 		/* hardware doesn't support it, choose a bigger one */
-- 
2.16.3