[PATCH v2 4/6] iommu/amd: Add support for Guest IO protection

[Vasant Hegde <vasant.hegde@amd.com>]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

AMD IOMMU introduces support for Guest I/O protection where the request
from the I/O device without a PASID are treated as if they have PASID 0.

Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
Changes in v2:
  - Added passthrough mode check
  - Added FEATURE_GT check

 drivers/iommu/amd/amd_iommu_types.h |  3 +++
 drivers/iommu/amd/init.c            | 13 +++++++++++++
 drivers/iommu/amd/iommu.c           |  4 ++++
 3 files changed, 20 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index a6d6a3c7c5f3..63bf521ba20c 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -93,6 +93,7 @@
 #define FEATURE_HE		(1ULL<<8)
 #define FEATURE_PC		(1ULL<<9)
 #define FEATURE_GAM_VAPIC	(1ULL<<21)
+#define FEATURE_GIOSUP		(1ULL<<48)
 #define FEATURE_EPHSUP		(1ULL<<50)
 #define FEATURE_SNP		(1ULL<<63)
 
@@ -370,6 +371,7 @@
 #define DTE_FLAG_IW (1ULL << 62)
 
 #define DTE_FLAG_IOTLB	(1ULL << 32)
+#define DTE_FLAG_GIOV	(1ULL << 54)
 #define DTE_FLAG_GV	(1ULL << 55)
 #define DTE_FLAG_MASK	(0x3ffULL << 32)
 #define DTE_GLX_SHIFT	(56)
@@ -428,6 +430,7 @@
 #define PD_PASSTHROUGH_MASK	(1UL << 2) /* domain has no page
 					      translation */
 #define PD_IOMMUV2_MASK		(1UL << 3) /* domain has gcr3 table */
+#define PD_GIOV_MASK		(1UL << 4) /* domain enable GIOV support */
 
 extern bool amd_iommu_dump;
 #define DUMP_printk(format, arg...)				\
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 3c82d9c5f1c0..a2929d8b44f4 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -2026,6 +2026,17 @@ static int __init iommu_init_pci(struct amd_iommu *iommu)
 
 	init_iommu_perf_ctr(iommu);
 
+	if (amd_iommu_pgtable == AMD_IOMMU_V2) {
+		if (!iommu_feature(iommu, FEATURE_GIOSUP) ||
+		    !iommu_feature(iommu, FEATURE_GT)) {
+			pr_warn("Cannot enable v2 page table for DMA-API. Fallback to v1.\n");
+			amd_iommu_pgtable = AMD_IOMMU_V1;
+		} else if (iommu_default_passthrough()) {
+			pr_warn("V2 page table doesn't support passthrough mode. Fallback to v1.\n");
+			amd_iommu_pgtable = AMD_IOMMU_V1;
+		}
+	}
+
 	if (is_rd890_iommu(iommu->dev)) {
 		int i, j;
 
@@ -2100,6 +2111,8 @@ static void print_iommu_info(void)
 		if (amd_iommu_xt_mode == IRQ_REMAP_X2APIC_MODE)
 			pr_info("X2APIC enabled\n");
 	}
+	if (amd_iommu_pgtable == AMD_IOMMU_V2)
+		pr_info("V2 page table enabled\n");
 }
 
 static int __init amd_iommu_init_pci(void)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 027ecd5fb4b2..2e67e6eecc31 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1553,6 +1553,7 @@ static void set_dte_entry(struct amd_iommu *iommu, u16 devid,
 
 	pte_root |= (domain->iop.mode & DEV_ENTRY_MODE_MASK)
 		    << DEV_ENTRY_MODE_SHIFT;
+
 	pte_root |= DTE_FLAG_IR | DTE_FLAG_IW | DTE_FLAG_V | DTE_FLAG_TV;
 
 	flags = dev_table[devid].data[1];
@@ -1589,6 +1590,9 @@ static void set_dte_entry(struct amd_iommu *iommu, u16 devid,
 
 		tmp = DTE_GCR3_VAL_C(gcr3) << DTE_GCR3_SHIFT_C;
 		flags    |= tmp;
+
+		if (domain->flags & PD_GIOV_MASK)
+			pte_root |= DTE_FLAG_GIOV;
 	}
 
 	flags &= ~DEV_DOMID_MASK;
-- 
2.31.1