[PATCH v5 15/24] iommu/amd: Add helper functions to manage DevID / DomID mapping tables
From: Suravee Suthikulpanit
Date: Mon Sep 14 2026 - 14:58:57 EST
Introduce amd_viommu_init_one() and amd_viommu_uninit_one().
These functions are called during IOMMUFD vIOMMU initialize and destroy.
Currently, it manages the IPA mapping for Device ID and Domain ID mapping
tables.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd/amd_iommu_types.h | 3 ++
drivers/iommu/amd/amd_viommu.h | 4 ++
drivers/iommu/amd/iommu.c | 1 +
drivers/iommu/amd/iommufd.c | 9 +++-
drivers/iommu/amd/viommu.c | 64 +++++++++++++++++++++++++++++
5 files changed, 80 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index 4b48ec8bacd6..fc8e1378c7ed 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -544,6 +544,9 @@ struct amd_iommu_viommu {
*/
struct xarray gdomid_array;
+ u64 *devid_table;
+ u64 *domid_table;
+
/* Offset for mmap() of guest VF MMIO; set after iommufd_viommu_alloc_mmap(). */
unsigned long vfmmio_mmap_offset;
};
diff --git a/drivers/iommu/amd/amd_viommu.h b/drivers/iommu/amd/amd_viommu.h
index 276f2126290f..580cad0f9f5a 100644
--- a/drivers/iommu/amd/amd_viommu.h
+++ b/drivers/iommu/amd/amd_viommu.h
@@ -16,6 +16,10 @@ void __init amd_viommu_uninit(struct amd_iommu *iommu);
u64 amd_viommu_get_vfmmio_addr(struct amd_iommu *iommu, u16 gid);
+int amd_viommu_init_one(struct amd_iommu *iommu, struct amd_iommu_viommu *viommu);
+
+void amd_viommu_uninit_one(struct amd_iommu *iommu, struct amd_iommu_viommu *viommu);
+
#else
/*
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index bcbd5af75d00..d620586d5734 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -43,6 +43,7 @@
#include <linux/generic_pt/iommu.h>
#include "amd_iommu.h"
+#include "amd_viommu.h"
#include "iommufd.h"
#include "../irq_remapping.h"
#include "../iommu-pages.h"
diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
index 2e34491e3cf7..97de07d3ad10 100644
--- a/drivers/iommu/amd/iommufd.c
+++ b/drivers/iommu/amd/iommufd.c
@@ -97,11 +97,15 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *
if (ret)
goto err_init;
+ ret = amd_viommu_init_one(iommu, aviommu);
+ if (ret)
+ goto err_init;
+
ret = iommu_copy_struct_to_user(user_data, &data,
IOMMU_VIOMMU_TYPE_AMD,
out_vfmmio_mmap_offset);
if (ret)
- goto err_init;
+ goto err_init_one;
viommu->ops = &amd_viommu_ops;
@@ -110,6 +114,8 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain *
spin_unlock_irqrestore(&pdom->lock, flags);
return 0;
+err_init_one:
+ amd_viommu_uninit_one(iommu, aviommu);
err_init:
iommufd_viommu_destroy_mmap(&aviommu->core, aviommu->vfmmio_mmap_offset);
err_mmap:
@@ -132,6 +138,7 @@ static void amd_iommufd_viommu_destroy(struct iommufd_viommu *viommu)
spin_unlock_irqrestore(&pdom->lock, flags);
xa_destroy(&aviommu->gdomid_array);
iommufd_viommu_destroy_mmap(&aviommu->core, aviommu->vfmmio_mmap_offset);
+ amd_viommu_uninit_one(iommu, aviommu);
amd_iommu_gid_free(iommu, aviommu->gid);
}
diff --git a/drivers/iommu/amd/viommu.c b/drivers/iommu/amd/viommu.c
index ad5f754f25a4..06a21f14b2a5 100644
--- a/drivers/iommu/amd/viommu.c
+++ b/drivers/iommu/amd/viommu.c
@@ -19,6 +19,32 @@
#include "amd_viommu.h"
#include "../iommu-pages.h"
+/*
+ * Per-vIOMMU DevID / DomID tables share iommu->viommu_pdom:
+ * IOVA = base + gid * entry_size, gid in [1, VIOMMU_MAX_GID].
+ * The 64GB gap between these bases is 0x10000 1MB DevID slots.
+ * VIOMMU_MAX_GID is 0x7FFF, so a max-gid DevID window ends at
+ * 0x1800000000 and cannot meet VIOMMU_DOMID_MAPPING_BASE.
+ *
+ * VIOMMU_MAX_GDEVID / VIOMMU_MAX_GDOMID are 16-bit guest DevID
+ * and DomID table indices (hardware mapping-table width), not GID.
+ */
+#define VIOMMU_MAX_GDEVID 0xFFFF
+#define VIOMMU_DEVID_MAPPING_BASE 0x1000000000ULL
+#define VIOMMU_DEVID_MAPPING_ENTRY_SIZE (1 << 20)
+
+#define VIOMMU_MAX_GDOMID 0xFFFF
+#define VIOMMU_DOMID_MAPPING_BASE 0x2000000000ULL
+#define VIOMMU_DOMID_MAPPING_ENTRY_SIZE (1 << 19)
+
+static_assert(VIOMMU_DEVID_MAPPING_BASE +
+ (VIOMMU_MAX_GID + 1ULL) * VIOMMU_DEVID_MAPPING_ENTRY_SIZE <=
+ VIOMMU_DOMID_MAPPING_BASE);
+static_assert(VIOMMU_DEVID_MAPPING_ENTRY_SIZE >=
+ (VIOMMU_MAX_GDEVID + 1ULL) * sizeof(u64));
+static_assert(VIOMMU_DOMID_MAPPING_ENTRY_SIZE >=
+ (VIOMMU_MAX_GDOMID + 1ULL) * sizeof(u64));
+
static void __init amd_viommu_vf_vfcntl_unmap(struct amd_iommu *iommu)
{
if (iommu->vfctrl_base) {
@@ -412,3 +438,41 @@ static void __maybe_unused free_private_vm_region(struct amd_iommu *iommu, u64 *
*entry = NULL;
}
+
+void amd_viommu_uninit_one(struct amd_iommu *iommu, struct amd_iommu_viommu *aviommu)
+{
+ pr_debug("%s: gid=%u\n", __func__, aviommu->gid);
+
+ free_private_vm_region(iommu, &aviommu->devid_table,
+ VIOMMU_DEVID_MAPPING_BASE,
+ VIOMMU_DEVID_MAPPING_ENTRY_SIZE,
+ aviommu->gid);
+ free_private_vm_region(iommu, &aviommu->domid_table,
+ VIOMMU_DOMID_MAPPING_BASE,
+ VIOMMU_DOMID_MAPPING_ENTRY_SIZE,
+ aviommu->gid);
+}
+
+int amd_viommu_init_one(struct amd_iommu *iommu, struct amd_iommu_viommu *viommu)
+{
+ int ret;
+
+ ret = alloc_private_vm_region(iommu, &viommu->devid_table,
+ VIOMMU_DEVID_MAPPING_BASE,
+ VIOMMU_DEVID_MAPPING_ENTRY_SIZE,
+ viommu->gid);
+ if (ret)
+ goto err_out;
+
+ ret = alloc_private_vm_region(iommu, &viommu->domid_table,
+ VIOMMU_DOMID_MAPPING_BASE,
+ VIOMMU_DOMID_MAPPING_ENTRY_SIZE,
+ viommu->gid);
+ if (ret)
+ goto err_out;
+
+ return 0;
+err_out:
+ amd_viommu_uninit_one(iommu, viommu);
+ return ret;
+}
--
2.34.1