Allow a vIOMMU object to allocate vIRQ Event Queues, with a condition that
each vIOMMU can only have one single vIRQ event queue per type.
Add iommufd_eventq_virq_alloc with an iommufd_eventq_virq_ops for this new
ioctl.
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
drivers/iommu/iommufd/iommufd_private.h | 57 +++++++++++
include/linux/iommufd.h | 3 +
include/uapi/linux/iommufd.h | 31 ++++++
drivers/iommu/iommufd/eventq.c | 129 ++++++++++++++++++++++++
drivers/iommu/iommufd/main.c | 6 ++
drivers/iommu/iommufd/viommu.c | 2 +
6 files changed, 228 insertions(+)
diff --git a/drivers/iommu/iommufd/iommufd_private.h
b/drivers/iommu/iommufd/iommufd_private.h
index dfbc5cfbd164..fab3b21ac687 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -547,6 +547,49 @@ static inline int iommufd_hwpt_replace_device(struct
iommufd_device *idev,
return iommu_group_replace_domain(idev->igroup->group, hwpt->domain);
}
+/*
+ * An iommufd_virq object represents an interface to deliver vIOMMU interrupts
+ * to the user space. These objects are created/destroyed by the user space and
+ * associated with vIOMMU object(s) during the allocations.
+ */
+struct iommufd_virq {
+ struct iommufd_eventq common;
+ struct iommufd_viommu *viommu;
+ struct list_head node;
+
+ unsigned int type;
+};
+
+static inline struct iommufd_virq *eventq_to_virq(struct iommufd_eventq
*eventq)
+{
+ return container_of(eventq, struct iommufd_virq, common);
+}
+
+static inline struct iommufd_virq *iommufd_get_virq(struct iommufd_ucmd *ucmd,
+ u32 id)
+{
+ return container_of(iommufd_get_object(ucmd->ictx, id,
+ IOMMUFD_OBJ_VIRQ),
+ struct iommufd_virq, common.obj);
+}
+
+int iommufd_virq_alloc(struct iommufd_ucmd *ucmd);
+void iommufd_virq_destroy(struct iommufd_object *obj);
+void iommufd_virq_abort(struct iommufd_object *obj);
+
+/* An iommufd_virq_header packs a vIOMMU interrupt in an iommufd_virq queue */
+struct iommufd_virq_header {
+ struct list_head node;
+ ssize_t irq_len;
+ void *irq_data;
+};
+
+static inline int iommufd_virq_handler(struct iommufd_virq *virq,
+ struct iommufd_virq_header *virq_header)
+{
+ return iommufd_eventq_notify(&virq->common, &virq_header->node);
+}
+
static inline struct iommufd_viommu *
iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id)
{
@@ -555,6 +598,20 @@ iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id)
struct iommufd_viommu, obj);
}
+static inline struct iommufd_virq *
+iommufd_viommu_find_virq(struct iommufd_viommu *viommu, u32 type)
+{
+ struct iommufd_virq *virq, *next;
+
+ lockdep_assert_held(&viommu->virqs_rwsem);
+
+ list_for_each_entry_safe(virq, next, &viommu->virqs, node) {
+ if (virq->type == type)
+ return virq;
+ }
+ return NULL;
+}
+
int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd);
void iommufd_viommu_destroy(struct iommufd_object *obj);
int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd);
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 11110c749200..b082676c9e43 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -34,6 +34,7 @@ enum iommufd_object_type {
IOMMUFD_OBJ_FAULT,
IOMMUFD_OBJ_VIOMMU,
IOMMUFD_OBJ_VDEVICE,
+ IOMMUFD_OBJ_VIRQ,
#ifdef CONFIG_IOMMUFD_TEST
IOMMUFD_OBJ_SELFTEST,
#endif
@@ -93,6 +94,8 @@ struct iommufd_viommu {
const struct iommufd_viommu_ops *ops;
struct xarray vdevs;
+ struct list_head virqs;
+ struct rw_semaphore virqs_rwsem;
unsigned int type;
};
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 34810f6ae2b5..cdf2dba28d4a 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -55,6 +55,7 @@ enum {
IOMMUFD_CMD_VIOMMU_ALLOC = 0x90,
IOMMUFD_CMD_VDEVICE_ALLOC = 0x91,
IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92,
+ IOMMUFD_CMD_VIRQ_ALLOC = 0x93,
};
/**
@@ -1012,4 +1013,34 @@ struct iommu_ioas_change_process {
#define IOMMU_IOAS_CHANGE_PROCESS \
_IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_CHANGE_PROCESS)
+/**
+ * enum iommu_virq_type - Virtual IRQ Type
+ * @IOMMU_VIRQ_TYPE_NONE: INVALID type
+ */
+enum iommu_virq_type {
+ IOMMU_VIRQ_TYPE_NONE = 0,
+};
+
+/**
+ * struct iommu_virq_alloc - ioctl(IOMMU_VIRQ_ALLOC)
+ * @size: sizeof(struct iommu_virq_alloc)
+ * @flags: Must be 0
+ * @viommu: virtual IOMMU ID to associate the virtual IRQ with
+ * @type: Type of the virtual IRQ. Must be defined in enum iommu_virq_type
+ * @out_virq_id: The ID of the new virtual IRQ
+ * @out_virq_fd: The fd of the new virtual IRQ. User space must close the
+ * successfully returned fd after using it
+ *
+ * Explicitly allocate a virtual IRQ interface for a vIOMMU. A vIOMMU can have
+ * multiple FDs for different @type, but is confined to one FD per @type.
+ */
+struct iommu_virq_alloc {
+ __u32 size;
+ __u32 flags;
+ __u32 viommu_id;
+ __u32 type;
+ __u32 out_virq_id;
+ __u32 out_virq_fd;
+};
+#define IOMMU_VIRQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIRQ_ALLOC)
#endif
diff --git a/drivers/iommu/iommufd/eventq.c b/drivers/iommu/iommufd/eventq.c
index e386b6c3e6ab..a8921c745d36 100644
--- a/drivers/iommu/iommufd/eventq.c
+++ b/drivers/iommu/iommufd/eventq.c
@@ -346,6 +346,73 @@ static const struct iommufd_eventq_ops iommufd_fault_ops =
{
.write = &iommufd_fault_fops_write,
};
+/* IOMMUFD_OBJ_VIRQ Functions */
+
+void iommufd_virq_abort(struct iommufd_object *obj)
+{
+ struct iommufd_eventq *eventq =
+ container_of(obj, struct iommufd_eventq, obj);
+ struct iommufd_virq *virq = eventq_to_virq(eventq);
+ struct iommufd_viommu *viommu = virq->viommu;
+ struct iommufd_virq_header *cur, *next;
+
+ lockdep_assert_held_write(&viommu->virqs_rwsem);
+
+ list_for_each_entry_safe(cur, next, &eventq->deliver, node) {
+ list_del(&cur->node);
+ kfree(cur);
+ }
+
+ refcount_dec(&viommu->obj.users);
+ mutex_destroy(&eventq->mutex);
+ list_del(&virq->node);
+}
+
+void iommufd_virq_destroy(struct iommufd_object *obj)
+{
+ struct iommufd_virq *virq =
+ eventq_to_virq(container_of(obj, struct iommufd_eventq, obj));
+
+ down_write(&virq->viommu->virqs_rwsem);
+ iommufd_virq_abort(obj);
+ up_write(&virq->viommu->virqs_rwsem);
+}
+
+static ssize_t iommufd_virq_fops_read(struct iommufd_eventq *eventq,
+ char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ size_t done = 0;
+ int rc = 0;
+
+ if (*ppos)
+ return -ESPIPE;
+
+ mutex_lock(&eventq->mutex);
+ while (!list_empty(&eventq->deliver) && count > done) {
+ struct iommufd_virq_header *cur = list_first_entry(
+ &eventq->deliver, struct iommufd_virq_header, node);
+
+ if (cur->irq_len > count - done)
+ break;
+
+ if (copy_to_user(buf + done, cur->irq_data, cur->irq_len)) {
+ rc = -EFAULT;
+ break;
+ }
+ done += cur->irq_len;
+ list_del(&cur->node);
+ kfree(cur);
+ }
+ mutex_unlock(&eventq->mutex);
+
+ return done == 0 ? rc : done;
+}
+
+static const struct iommufd_eventq_ops iommufd_virq_ops = {
+ .read = &iommufd_virq_fops_read,
+};
+
/* Common Event Queue Functions */
static ssize_t iommufd_eventq_fops_read(struct file *filep, char __user *buf,
@@ -473,3 +540,65 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
return rc;
}
+
+int iommufd_virq_alloc(struct iommufd_ucmd *ucmd)
+{
+ struct iommu_virq_alloc *cmd = ucmd->cmd;
+ struct iommufd_viommu *viommu;
+ struct iommufd_virq *virq;
+ int fdno;
+ int rc;
+
+ if (cmd->flags || cmd->type == IOMMU_VIRQ_TYPE_NONE)
+ return -EOPNOTSUPP;
+
+ viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
+ if (IS_ERR(viommu))
+ return PTR_ERR(viommu);
+ down_write(&viommu->virqs_rwsem);
+
+ if (iommufd_viommu_find_virq(viommu, cmd->type)) {
+ rc = -EEXIST;
+ goto out_unlock_virqs;
+ }
+
+ virq = __iommufd_object_alloc(ucmd->ictx, virq, IOMMUFD_OBJ_VIRQ,
+ common.obj);
+ if (IS_ERR(virq)) {
+ rc = PTR_ERR(virq);
+ goto out_unlock_virqs;
+ }
+
+ virq->type = cmd->type;
+ virq->viommu = viommu;
+ refcount_inc(&viommu->obj.users);
+ list_add_tail(&virq->node, &viommu->virqs);
+
+ fdno = iommufd_eventq_init(&virq->common, "[iommufd-viommu-irq]",
+ ucmd->ictx, &iommufd_virq_ops);
+ if (fdno < 0) {
+ rc = fdno;
+ goto out_abort;
+ }
+
+ cmd->out_virq_id = virq->common.obj.id;
+ cmd->out_virq_fd = fdno;
+
+ rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+ if (rc)
+ goto out_put_fdno;
+
+ iommufd_object_finalize(ucmd->ictx, &virq->common.obj);
+ fd_install(fdno, virq->common.filep);
+ goto out_unlock_virqs;
+
+out_put_fdno:
+ put_unused_fd(fdno);
+ fput(virq->common.filep);
+out_abort:
+ iommufd_object_abort_and_destroy(ucmd->ictx, &virq->common.obj);
+out_unlock_virqs:
+ up_write(&viommu->virqs_rwsem);
+ iommufd_put_object(ucmd->ictx, &viommu->obj);
+ return rc;
+}
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index cfbdf7b0e3c1..9d15978ef882 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -367,6 +367,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
__reserved),
IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl,
struct iommu_viommu_alloc, out_viommu_id),
+ IOCTL_OP(IOMMU_VIRQ_ALLOC, iommufd_virq_alloc, struct iommu_virq_alloc,
+ out_virq_fd),
#ifdef CONFIG_IOMMUFD_TEST
IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
#endif
@@ -502,6 +504,10 @@ static const struct iommufd_object_ops
iommufd_object_ops[] = {
[IOMMUFD_OBJ_FAULT] = {
.destroy = iommufd_fault_destroy,
},
+ [IOMMUFD_OBJ_VIRQ] = {
+ .destroy = iommufd_virq_destroy,
+ .abort = iommufd_virq_abort,
+ },
[IOMMUFD_OBJ_VIOMMU] = {
.destroy = iommufd_viommu_destroy,
},
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 69b88e8c7c26..075b6aed79bc 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -59,6 +59,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
viommu->ictx = ucmd->ictx;
viommu->hwpt = hwpt_paging;
refcount_inc(&viommu->hwpt->common.obj.users);
+ INIT_LIST_HEAD(&viommu->virqs);
+ init_rwsem(&viommu->virqs_rwsem);
/*
* It is the most likely case that a physical IOMMU is unpluggable. A
* pluggable IOMMU instance (if exists) is responsible for refcounting
--
2.43.0
