[RFC PATCH v4 03/16] iommu/arm-smmu-v3: Add initial pSMMU realm viommu plumbing
Aneesh Kumar K.V (Arm)
aneesh.kumar at kernel.org
Mon Apr 27 01:53:31 PDT 2026
Add initial plumbing for Realm pSMMU integration in the arm-smmu-v3 iommufd
path.
Changes include:
- add RMI SMC IDs and helper wrappers for pSMMU activate and ST_L2 create/destroy
- add RMI pSMMU parameter structure definitions
- add IOMMU_VIOMMU_TYPE_ARM_REALM_SMMUV3 UAPI/internal type support
- add arm-smmu-v3 realm viommu init/vdevice hooks
- store SMMU MMIO physical base and realm initialization state in arm_smmu_device
This enables basic realm pSMMU setup and vdevice stream-table operations.
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar at kernel.org>
---
arch/arm64/include/asm/rmi_cmds.h | 7 +
arch/arm64/include/asm/rmi_smc.h | 18 +++
arch/arm64/kernel/rmi.c | 39 +++++
.../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 7 +
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-realm.c | 148 ++++++++++++++++++
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 1 +
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 4 +
include/uapi/linux/iommufd.h | 1 +
8 files changed, 225 insertions(+)
diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h
index 75eb59d4fa84..659d68ad5f1d 100644
--- a/arch/arm64/include/asm/rmi_cmds.h
+++ b/arch/arm64/include/asm/rmi_cmds.h
@@ -863,4 +863,11 @@ static inline unsigned long rmi_psmmu_event_consume(unsigned long psmmu_phys,
return res.a0;
}
+int rmi_psmmu_activate(unsigned long psmmu_phys,
+ unsigned long psmmu_params_phys, unsigned long *rmi_ret);
+int rmi_psmmu_st_l2_create(unsigned long psmmu_phys,
+ unsigned long stream_id, unsigned long *rmi_ret);
+int rmi_psmmu_st_l2_destroy(unsigned long psmmu_phys,
+ unsigned long stream_id, unsigned long *rmi_ret);
+
#endif /* __ASM_RMI_CMDS_H */
diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
index be1b1e95a937..5b540d25914e 100644
--- a/arch/arm64/include/asm/rmi_smc.h
+++ b/arch/arm64/include/asm/rmi_smc.h
@@ -625,4 +625,22 @@ struct rmi_psmmu_info {
};
};
+#define RMI_PSMMU_FLAG_MSI BIT(0)
+#define RMI_PSMMU_FLAG_ATS BIT(1)
+#define RMI_PSMMU_FLAG_PRI BIT(2)
+struct rmi_psmmu_params {
+ union {
+ struct {
+ u64 flags;
+ u64 grr_addr;
+ u64 grr_data;
+ u64 eventq_addr;
+ u64 eventq_data;
+ u64 priq_addr;
+ u64 priq_data;
+ };
+ u8 padding5[0x1000];
+ };
+};
+
#endif /* __ASM_RMI_SMC_H */
diff --git a/arch/arm64/kernel/rmi.c b/arch/arm64/kernel/rmi.c
index da4707981548..cc4050db5a6a 100644
--- a/arch/arm64/kernel/rmi.c
+++ b/arch/arm64/kernel/rmi.c
@@ -423,6 +423,45 @@ unsigned long rmi_sro_execute(struct rmi_sro_state *sro)
return regs.a0;
}
+int rmi_psmmu_activate(unsigned long psmmu_phys,
+ unsigned long psmmu_params_phys, unsigned long *rmi_ret)
+{
+ struct rmi_sro_state *sro __free(sro) =
+ rmi_sro_init(SMC_RMI_PSMMU_ACTIVATE, psmmu_phys, psmmu_params_phys);
+ if (!sro)
+ return -ENOMEM;
+
+ *rmi_ret = rmi_sro_execute(sro);
+
+ return 0;
+}
+
+int rmi_psmmu_st_l2_create(unsigned long psmmu_phys,
+ unsigned long stream_id, unsigned long *rmi_ret)
+{
+ struct rmi_sro_state *sro __free(sro) =
+ rmi_sro_init(SMC_RMI_PSMMU_ST_L2_CREATE, psmmu_phys, stream_id);
+ if (!sro)
+ return -ENOMEM;
+
+ *rmi_ret = rmi_sro_execute(sro);
+
+ return 0;
+}
+
+int rmi_psmmu_st_l2_destroy(unsigned long psmmu_phys,
+ unsigned long stream_id, unsigned long *rmi_ret)
+{
+ struct rmi_sro_state *sro __free(sro) =
+ rmi_sro_init(SMC_RMI_PSMMU_ST_L2_DESTROY, psmmu_phys, stream_id);
+ if (!sro)
+ return -ENOMEM;
+
+ *rmi_ret = rmi_sro_execute(sro);
+
+ return 0;
+}
+
static int rmi_configure(void)
{
struct rmm_config *config __free(free_page) = NULL;
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
index ddae0b07c76b..c98e91b3ca13 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c
@@ -437,6 +437,9 @@ size_t arm_smmu_get_viommu_size(struct device *dev,
if (viommu_type == IOMMU_VIOMMU_TYPE_ARM_SMMUV3)
return VIOMMU_STRUCT_SIZE(struct arm_vsmmu, core);
+ if (viommu_type == IOMMU_VIOMMU_TYPE_ARM_REALM_SMMUV3)
+ return VIOMMU_STRUCT_SIZE(struct arm_vsmmu, core);
+
if (!smmu->impl_ops || !smmu->impl_ops->get_viommu_size)
return 0;
return smmu->impl_ops->get_viommu_size(viommu_type);
@@ -464,6 +467,10 @@ int arm_vsmmu_init(struct iommufd_viommu *viommu,
return 0;
}
+ if (viommu->type == IOMMU_VIOMMU_TYPE_ARM_REALM_SMMUV3)
+ return arm_realm_smmu_v3_init(viommu, user_data);
+
+
return smmu->impl_ops->vsmmu_init(vsmmu, user_data);
}
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-realm.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-realm.c
index fec1a32de53c..6f8de7cead9d 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-realm.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-realm.c
@@ -6,6 +6,7 @@
#include <linux/interrupt.h>
#include <asm/rmi_smc.h>
#include <asm/rmi_cmds.h>
+#include <asm/kvm_emulate.h>
#include "arm-smmu-v3.h"
@@ -122,3 +123,150 @@ void arm_smmu_setup_realm_irqs(struct arm_smmu_device *smmu)
}
}
}
+
+static void arm_realm_smmu_v3_destroy(struct iommufd_viommu *viommu)
+{
+ /* When we add refcount psmmu deactivate here. */
+}
+
+static void arm_realm_smmu_v3_vdevice_destroy(struct iommufd_vdevice *vdev)
+{
+ struct device *dev = iommufd_vdevice_to_device(vdev);
+ struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+ /* FIXME which stream to pick */
+ /* At this moment, iommufd only supports PCI device that has one SID */
+ struct arm_smmu_stream *stream = &master->streams[0];
+ struct arm_smmu_device *smmu = master->smmu;
+ unsigned long rmi_ret = 0;
+ int ret;
+
+ if (!smmu->realm_initialized)
+ return;
+
+ ret = rmi_psmmu_st_l2_destroy(smmu->base_phys,
+ ALIGN_DOWN(stream->id, STRTAB_NUM_L2_STES),
+ &rmi_ret);
+ if (ret || rmi_ret) {
+
+ /* Table in use */
+ if (RMI_RETURN_STATUS(rmi_ret) == RMI_ERROR_PSMMU_ST &&
+ RMI_RETURN_INDEX(rmi_ret) == 2)
+ return;
+
+ dev_warn(dev, "failed to destroy realm stream mapping\n");
+ }
+}
+
+static int arm_realm_smmu_v3_vdevice_init(struct iommufd_vdevice *vdev)
+{
+ struct device *dev = iommufd_vdevice_to_device(vdev);
+ struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+ // fixme which stream to pick
+ /* At this moment, iommufd only supports PCI device that has one SID */
+ struct arm_smmu_stream *stream = &master->streams[0];
+ struct arm_smmu_device *smmu = master->smmu;
+ unsigned long rmi_ret = 0;
+ int ret;
+
+ if (!smmu->realm_initialized)
+ return -EINVAL;
+
+ ret = rmi_psmmu_st_l2_create(smmu->base_phys,
+ ALIGN_DOWN(stream->id, STRTAB_NUM_L2_STES),
+ &rmi_ret);
+ if (ret || rmi_ret) {
+ if (!ret)
+ return -EIO;
+ if (RMI_RETURN_STATUS(rmi_ret) == RMI_ERROR_PSMMU_ST &&
+ RMI_RETURN_INDEX(rmi_ret) == 2) {
+ /* table already exist */
+ vdev->destroy = arm_realm_smmu_v3_vdevice_destroy;
+ return 0;
+ }
+ dev_warn(dev, "failed to create realm stream mapping\n");
+ return -EIO;
+ }
+ vdev->destroy = arm_realm_smmu_v3_vdevice_destroy;
+ return 0;
+}
+
+static const struct iommufd_viommu_ops arm_realm_smmu_v3_ops = {
+ .destroy = arm_realm_smmu_v3_destroy,
+ .alloc_domain_nested = arm_vsmmu_alloc_domain_nested,
+ .cache_invalidate = arm_vsmmu_cache_invalidate,
+ .vdevice_init = arm_realm_smmu_v3_vdevice_init,
+};
+
+static int get_irq_data(int irq, u64 *msi_addr, u64 *msi_data)
+{
+ struct msi_desc *desc;
+
+ desc = irq_get_msi_desc(irq);
+ if (!desc)
+ return -EINVAL;
+
+ *msi_addr = (((u64)desc->msg.address_hi) << 32) | desc->msg.address_lo;
+ *msi_data = desc->msg.data;
+ return 0;
+}
+
+int arm_realm_smmu_v3_init(struct iommufd_viommu *viommu,
+ const struct iommu_user_data *user_data)
+{
+ int ret = 0;
+ struct kvm *kvm = viommu->kvm;
+ struct rmi_psmmu_params *params;
+ struct arm_smmu_device *smmu =
+ container_of(viommu->iommu_dev, struct arm_smmu_device, iommu);
+ unsigned long rmi_ret;
+
+ if (!kvm)
+ return -EINVAL;
+
+ if (!kvm_is_realm(kvm))
+ return -EINVAL;
+
+ if (!(smmu->features & ARM_SMMU_FEAT_RME))
+ return -EOPNOTSUPP;
+
+ if (smmu->realm_initialized)
+ goto psmmu_already_active;
+
+ params = (struct rmi_psmmu_params *)get_zeroed_page(GFP_KERNEL);
+ if (!params)
+ return -ENOMEM;
+
+ /* No ATS and PRI support */
+ if (!(smmu->features & ARM_SMMU_FEAT_MSI))
+ goto psmmu_activate;
+
+ params->flags = RMI_PSMMU_FLAG_MSI;
+ if (get_irq_data(smmu->realm_gerr_irq,
+ ¶ms->grr_addr, ¶ms->grr_data)) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+ if (get_irq_data(smmu->realm_evtq_irq,
+ ¶ms->eventq_addr, ¶ms->eventq_data)) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+psmmu_activate:
+ ret = rmi_psmmu_activate(smmu->base_phys, virt_to_phys(params),
+ &rmi_ret);
+ if (ret || rmi_ret) {
+ if (!ret)
+ ret = -EIO;
+ dev_warn(smmu->dev, "failed to activate realm pSMMU\n");
+ ret = -EIO;
+ } else {
+ smmu->realm_initialized = true;
+ }
+out_free:
+ free_page((unsigned long)params);
+psmmu_already_active:
+ if (!ret)
+ viommu->ops = &arm_realm_smmu_v3_ops;
+ return ret;
+}
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 17fd99887aab..1e3d4d682e32 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3956,6 +3956,7 @@ static int arm_smmu_init_structures(struct arm_smmu_device *smmu)
if (ret)
return ret;
+ smmu->realm_initialized = false;
if (smmu->impl_ops && smmu->impl_ops->init_structures)
return smmu->impl_ops->init_structures(smmu);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 6680516b571b..d528b3212d38 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -811,6 +811,8 @@ struct arm_smmu_device {
struct rb_root streams;
struct mutex streams_mutex;
+
+ bool realm_initialized;
};
struct arm_smmu_stream {
@@ -1073,6 +1075,8 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
const struct iommu_user_data *user_data);
int arm_vsmmu_cache_invalidate(struct iommufd_viommu *viommu,
struct iommu_user_data_array *array);
+int arm_realm_smmu_v3_init(struct iommufd_viommu *viommu,
+ const struct iommu_user_data *user_data);
#else
#define arm_smmu_get_viommu_size NULL
#define arm_smmu_hw_info NULL
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 47213663c0c1..74afc9967c3e 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -1055,6 +1055,7 @@ enum iommu_viommu_type {
IOMMU_VIOMMU_TYPE_DEFAULT = 0,
IOMMU_VIOMMU_TYPE_ARM_SMMUV3 = 1,
IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV = 2,
+ IOMMU_VIOMMU_TYPE_ARM_REALM_SMMUV3 = 3,
};
/**
--
2.43.0
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