[RFCv2 PATCH 1/7] iommu/amd: Introduce struct gcr3_tbl_info.giov

[Suravee Suthikulpanit]

To track DTE[GIOV] programming during IOMMU domain attach, also add logic
to determine if the GIOV is required, and set the variable accordinglly.

This is also a preparation for adding nested domain support, where the GIOV
setting is determined by the child domain.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
 drivers/iommu/amd/amd_iommu_types.h |  1 +
 drivers/iommu/amd/iommu.c           | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 3dc39bbc05fc..ff56c857f6ad 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -536,6 +536,7 @@ struct gcr3_tbl_info {
 	u64	*gcr3_tbl;	/* Guest CR3 table */
 	int	glx;		/* Number of levels for GCR3 table */
 	u32	pasid_cnt;	/* Track attached PASIDs */
+	bool	giov;		/* Track DTE[GIOV] */
 };
 
 struct amd_io_pgtable {
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4e4ff1550cf3..b9759f6d8be2 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1990,8 +1990,7 @@ static void set_dte_entry(struct amd_iommu *iommu,
 				((u64)GUEST_PGTABLE_5_LEVEL << DTE_GPT_LEVEL_SHIFT);
 		}
 
-		/* GIOV is supported with V2 page table mode only */
-		if (pdom_is_v2_pgtbl_mode(domain))
+		if (gcr3_info->giov)
 			pte_root |= DTE_FLAG_GIOV;
 	}
 
@@ -2067,6 +2066,14 @@ static int do_attach(struct iommu_dev_data *dev_data,
 			free_gcr3_table(dev_data);
 			return ret;
 		}
+
+		/*
+		 * GIOV is required for PD_MODE_V2 because we need
+		 * to support the case where the end-point device
+		 * does not have PASID in the TLP prefix when setting
+		 * up to use the v2 table.
+		 */
+		dev_data->gcr3_info.giov = true;
 	}
 
 	/* Update device table */
-- 
2.34.1