[PATCH v3 09/15] iommu/amd: Always enable GCR3TRPMode when supported.

Suravee Suthikulpanit posted 15 patches 2 months, 1 week ago
There is a newer version of this series
[PATCH v3 09/15] iommu/amd: Always enable GCR3TRPMode when supported.
Posted by Suravee Suthikulpanit 2 months, 1 week ago
The GCR3TRPMode feature allows the DTE[GCR3TRP] field to be configured
with GPA (instead of SPA). This simplifies the implementation, and is
a pre-requisite for nested translation support.

Therefore, always enable this feature if available.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/amd_iommu_types.h | 1 +
 drivers/iommu/amd/init.c            | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 556f1df32d53..9226edd8af69 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -185,6 +185,7 @@
 #define CONTROL_EPH_EN		45
 #define CONTROL_XT_EN		50
 #define CONTROL_INTCAPXT_EN	51
+#define CONTROL_GCR3TRPMODE	58
 #define CONTROL_IRTCACHEDIS	59
 #define CONTROL_SNPAVIC_EN	61
 
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index f2991c11867c..c45a4bd89569 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1122,6 +1122,9 @@ static void iommu_enable_gt(struct amd_iommu *iommu)
 		return;
 
 	iommu_feature_enable(iommu, CONTROL_GT_EN);
+
+	if (check_feature2(FEATURE_GCR3TRPMODE))
+		iommu_feature_enable(iommu, CONTROL_GCR3TRPMODE);
 }
 
 /* sets a specific bit in the device table entry. */
-- 
2.34.1
Re: [PATCH v3 09/15] iommu/amd: Always enable GCR3TRPMode when supported.
Posted by Jason Gunthorpe 2 months, 1 week ago
On Thu, Oct 09, 2025 at 11:57:49PM +0000, Suravee Suthikulpanit wrote:
> The GCR3TRPMode feature allows the DTE[GCR3TRP] field to be configured
> with GPA (instead of SPA). This simplifies the implementation, and is
> a pre-requisite for nested translation support.
> 
> Therefore, always enable this feature if available.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> ---
>  drivers/iommu/amd/amd_iommu_types.h | 1 +
>  drivers/iommu/amd/init.c            | 3 +++
>  2 files changed, 4 insertions(+)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason