iommu/amd: Introduce struct protection_domain.pd_mode

This enum variable is used to track the type of page table used by the
protection domain. It will replace the protection_domain.flags in
subsequent series.
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240205115615.6053-5-vasant.hegde@amd.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/amd_iommu_types.h

@@ -541,6 +541,11 @@ struct amd_io_pgtable {
 	u64			*pgd;		/* v2 pgtable pgd pointer */
 };
 
+enum protection_domain_mode {
+	PD_MODE_V1 = 1,
+	PD_MODE_V2,
+};
+
 /*
  * This structure contains generic data for  IOMMU protection domains
  * independent of their use.
@@ -556,6 +561,7 @@ struct protection_domain {
 	int nid;		/* Node ID */
 	u64 *gcr3_tbl;		/* Guest CR3 table */
 	unsigned long flags;	/* flags to find out type of domain */
+	enum protection_domain_mode pd_mode; /* Track page table type */
 	bool dirty_tracking;	/* dirty tracking is enabled in the domain */
 	unsigned dev_cnt;	/* devices assigned to this domain */
 	unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */

drivers/iommu/amd/iommu.c

@@ -2068,6 +2068,7 @@ static int protection_domain_init_v1(struct protection_domain *domain, int mode)
 			return -ENOMEM;
 	}
 
+	domain->pd_mode = PD_MODE_V1;
 	amd_iommu_domain_set_pgtable(domain, pt_root, mode);
 
 	return 0;
@@ -2076,6 +2077,7 @@ static int protection_domain_init_v1(struct protection_domain *domain, int mode)
 static int protection_domain_init_v2(struct protection_domain *domain)
 {
 	domain->flags |= PD_GIOV_MASK;
+	domain->pd_mode = PD_MODE_V2;
 
 	domain->domain.pgsize_bitmap = AMD_IOMMU_PGSIZES_V2;