iommu/amd: Enable Guest Translation after reading IOMMU feature register

Commit 8e01797 ("iommu/amd: Enable Guest Translation before
registering devices") moved IOMMU Guest Translation (GT) enablement to
early init path. It does feature check based on Global EFR value (got from
ACPI IVRS table). Later it adjusts EFR value based on IOMMU feature
register (late_iommu_features_init()).

It seems in some systems BIOS doesn't set gloabl EFR value properly.
This is causing mismatch. Hence move IOMMU GT enablement after
late_iommu_features_init() so that it does check based on IOMMU EFR
value.

Fixes: 8e01797 ("iommu/amd: Enable Guest Translation before registering devices")
Reported-by: Klara Modin <[email protected]>
Closes: https://lore.kernel.org/linux-iommu/[email protected]/
Signed-off-by: Vasant Hegde <[email protected]>
Tested-by: Klara Modin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: hegdevasant

drivers/iommu/amd/init.c

@@ -2046,6 +2046,8 @@ static int __init iommu_init_pci(struct amd_iommu *iommu)
 			amd_iommu_max_glx_val = glxval;
 		else
 			amd_iommu_max_glx_val = min(amd_iommu_max_glx_val, glxval);
+
+		iommu_enable_gt(iommu);
 	}
 
 	if (check_feature(FEATURE_PPR) && amd_iommu_alloc_ppr_log(iommu))
@@ -2732,7 +2734,6 @@ static void early_enable_iommu(struct amd_iommu *iommu)
 	iommu_enable_command_buffer(iommu);
 	iommu_enable_event_buffer(iommu);
 	iommu_set_exclusion_range(iommu);
-	iommu_enable_gt(iommu);
 	iommu_enable_ga(iommu);
 	iommu_enable_xt(iommu);
 	iommu_enable_irtcachedis(iommu);
@@ -2789,7 +2790,6 @@ static void early_enable_iommus(void)
 			iommu_disable_irtcachedis(iommu);
 			iommu_enable_command_buffer(iommu);
 			iommu_enable_event_buffer(iommu);
-			iommu_enable_gt(iommu);
 			iommu_enable_ga(iommu);
 			iommu_enable_xt(iommu);
 			iommu_enable_irtcachedis(iommu);