[PATCH 14/22] iommu/amd: Introduce IOMMUFD vDevice support for AMD

Suravee Suthikulpanit
2026-03-30T08:43:53Z

Initialize vDevice for AMD vIOMMU by setting up the Device ID Mapping
table using the guest device ID.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
drivers/iommu/amd/amd_iommu_types.h | 12 +++++++++++
drivers/iommu/amd/iommufd.c | 33 +++++++++++++++++++++++++++++
drivers/iommu/amd/nested.c | 12 +++++++++++
3 files changed, 57 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index fda7109766f3..c50ba5cda82d 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -386,6 +386,11 @@
#define DTE_GPT_LEVEL_SHIFT 54
#define DTE_GPT_LEVEL_MASK GENMASK_ULL(55, 54)

+/* vIOMMU bit fields */
+#define DTE_VIOMMU_EN_SHIFT 15
+#define DTE_VIOMMU_GDEVICEID_MASK GENMASK_ULL(31, 16)
+#define DTE_VIOMMU_GUESTID_MASK GENMASK_ULL(47, 32)
+
#define GCR3_VALID 0x01ULL

/* DTE[128:179] | DTE[184:191] */
@@ -887,6 +892,9 @@ struct iommu_dev_data {
bool defer_attach;

struct ratelimit_state rs; /* Ratelimit IOPF messages */
+
+ u16 gid; /* Guest ID */
+ u16 gDevId; /* Guest Device ID */
};

/* Map HPET and IOAPIC ids to the devid used by the IOMMU */
@@ -1113,6 +1121,10 @@ struct amd_irte_ops {
void (*clear_allocated)(struct irq_remap_table *, int);
};

+struct amd_iommu_vdevice {
+ struct iommufd_vdevice core;
+};
+
#ifdef CONFIG_IRQ_REMAP
extern struct amd_irte_ops irte_32_ops;
extern struct amd_irte_ops irte_128_ops;
diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c
index c2281557b3bf..a047bb45aa14 100644
--- a/drivers/iommu/amd/iommufd.c
+++ b/drivers/iommu/amd/iommufd.c
@@ -9,6 +9,7 @@
#include "amd_iommu.h"
#include "amd_viommu.h"
#include "amd_iommu_types.h"
+#include "../iommufd/iommufd_private.h"

static const struct iommufd_viommu_ops amd_viommu_ops;

@@ -123,6 +124,36 @@ static void amd_iommufd_viommu_destroy(struct iommufd_viommu *viommu)
amd_viommu_uninit_one(iommu, aviommu);
}

+/*
+ * Called from drivers/iommu/iommufd/viommu.c: iommufd_vdevice_alloc_ioctl()
+ */
+static int _amd_viommu_vdevice_init(struct iommufd_vdevice *vdev)
+{
+ struct iommu_dev_data *dev_data;
+ struct pci_dev *pdev = to_pci_dev(vdev->idev->dev);
+ struct iommufd_viommu *viommu = vdev->viommu;
+ struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core);
+
+ if (!pdev) {
+ pr_err();
+ return -EINVAL;
+ }
+
+ dev_data = dev_iommu_priv_get(&pdev->dev);
+ if (!dev_data) {
+ pr_err("%s: Device not found (devid=%#x)\n",
+ __func__, pci_dev_id(pdev));
+ return -EINVAL;
+ }
+
+ dev_data->gid = aviommu->gid;
+ dev_data->gDevId = vdev->virt_id;
+ pr_debug("%s: gid=%#x, hdev_id=%#x, gdev_id=%#x\n", __func__,
+ dev_data->gid, pci_dev_id(pdev), dev_data->gDevId);
+
+ return 0;
+}
+
/*
* See include/linux/iommufd.h
* struct iommufd_viommu_ops - vIOMMU specific operations
@@ -130,4 +161,6 @@ static void amd_iommufd_viommu_destroy(struct iommufd_viommu *viommu)
static const struct iommufd_viommu_ops amd_viommu_ops = {
.alloc_domain_nested = amd_iommu_alloc_domain_nested,
.destroy = amd_iommufd_viommu_destroy,
+ .vdevice_size = VDEVICE_STRUCT_SIZE(struct amd_iommu_vdevice, core),
+ .vdevice_init = _amd_viommu_vdevice_init,
};
diff --git a/drivers/iommu/amd/nested.c b/drivers/iommu/amd/nested.c
index c210b8003fd5..70af39da9360 100644
--- a/drivers/iommu/amd/nested.c
+++ b/drivers/iommu/amd/nested.c
@@ -227,6 +227,18 @@ static void set_dte_nested(struct amd_iommu *iommu, struct iommu_domain *dom,

/* Guest paging mode */
new->data[2] |= gdte->dte[2] & DTE_GPT_LEVEL_MASK;
+
+ /* vImuEn */
+ new->data[3] |= 1ULL << DTE_VIOMMU_EN_SHIFT;
+
+ /* GDeviceID */
+ new->data[3] |= FIELD_PREP(DTE_VIOMMU_GDEVICEID_MASK,
+ dev_data->gDevId);
+
+ /* GuestID */
+ new->data[3] |= FIELD_PREP(DTE_VIOMMU_GUESTID_MASK,
+ dev_data->gid);
+
}

static int nested_attach_device(struct iommu_domain *dom, struct device *dev,
--
2.34.1