Introduce a new IOMMUFD_CMD_VQUEUE_ALLOC ioctl for user space to allocate
a vQUEUE object for a vIOMMU specific HW-accelerated virtual queue, e.g.:
- NVIDIA's Virtual Command Queue
- AMD vIOMMU's Command Buffer, Event Log Buffer, and PPR Log Buffer
This is a vIOMMU based ioctl. Simply increase the refcount of the vIOMMU.
Reviewed-by: Pranjal Shrivastava <pr...@google.com>
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
drivers/iommu/iommufd/iommufd_private.h | 2 +
include/uapi/linux/iommufd.h | 44 +++++++++++
drivers/iommu/iommufd/main.c | 6 ++
drivers/iommu/iommufd/viommu.c | 99 +++++++++++++++++++++++++
4 files changed, 151 insertions(+)
diff --git a/drivers/iommu/iommufd/iommufd_private.h
b/drivers/iommu/iommufd/iommufd_private.h
index 79160b039bc7..595d5e7021c4 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -611,6 +611,8 @@ 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);
void iommufd_vdevice_destroy(struct iommufd_object *obj);
+int iommufd_vqueue_alloc_ioctl(struct iommufd_ucmd *ucmd);
+void iommufd_vqueue_destroy(struct iommufd_object *obj);
#ifdef CONFIG_IOMMUFD_TEST
int iommufd_test(struct iommufd_ucmd *ucmd);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index cc90299a08d9..c6742bb00a41 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -56,6 +56,7 @@ enum {
IOMMUFD_CMD_VDEVICE_ALLOC = 0x91,
IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92,
IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93,
+ IOMMUFD_CMD_VQUEUE_ALLOC = 0x94,
};
/**
@@ -1147,4 +1148,47 @@ struct iommu_veventq_alloc {
__u32 __reserved;
};
#define IOMMU_VEVENTQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VEVENTQ_ALLOC)
+
+/**
+ * enum iommu_vqueue_type - Virtual Queue Type
+ * @IOMMU_VQUEUE_TYPE_DEFAULT: Reserved for future use
+ */
+enum iommu_vqueue_type {
+ IOMMU_VQUEUE_TYPE_DEFAULT = 0,
+};
+
+/**
+ * struct iommu_vqueue_alloc - ioctl(IOMMU_VQUEUE_ALLOC)
+ * @size: sizeof(struct iommu_vqueue_alloc)
+ * @flags: Must be 0
+ * @viommu_id: Virtual IOMMU ID to associate the virtual queue with
+ * @type: One of enum iommu_vqueue_type
+ * @index: The logical index to the virtual queue per virtual IOMMU, for a
multi
+ * queue model
+ * @out_vqueue_id: The ID of the new virtual queue
+ * @addr: Base address of the queue memory in the guest physical address space
+ * @length: Length of the queue memory in the guest physical address space
+ *
+ * Allocate a virtual queue object for a vIOMMU-specific HW-acceleration
feature
+ * that allows HW to access a guest queue memory described by @addr and
@length.
+ * It's suggested for VMM to back the queue memory using a single huge page
with
+ * a proper alignment for its contiguity in the host physical address space.
The
+ * call will fail, if the queue memory is not contiguous in the physical
address
+ * space. Upon success, its underlying physical pages will be pinned to prevent
+ * VMM from unmapping them in the IOAS, until the virtual queue gets destroyed.
+ *
+ * A vIOMMU can allocate multiple queues, but it must use a different @index to
+ * separate each allocation, e.g. VCMDQ0, VCMDQ1, ...
+ */
+struct iommu_vqueue_alloc {
+ __u32 size;
+ __u32 flags;
+ __u32 viommu_id;
+ __u32 type;
+ __u32 index;
+ __u32 out_vqueue_id;
+ __aligned_u64 addr;
+ __aligned_u64 length;
+};
+#define IOMMU_VQUEUE_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VQUEUE_ALLOC)
#endif
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 2b9ee9b4a424..23ed58f1f7b1 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -307,6 +307,7 @@ union ucmd_buffer {
struct iommu_veventq_alloc veventq;
struct iommu_vfio_ioas vfio_ioas;
struct iommu_viommu_alloc viommu;
+ struct iommu_vqueue_alloc vqueue;
#ifdef CONFIG_IOMMUFD_TEST
struct iommu_test_cmd test;
#endif
@@ -366,6 +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_VQUEUE_ALLOC, iommufd_vqueue_alloc_ioctl,
+ struct iommu_vqueue_alloc, length),
#ifdef CONFIG_IOMMUFD_TEST
IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last),
#endif
@@ -511,6 +514,9 @@ static const struct iommufd_object_ops iommufd_object_ops[]
= {
[IOMMUFD_OBJ_VIOMMU] = {
.destroy = iommufd_viommu_destroy,
},
+ [IOMMUFD_OBJ_VQUEUE] = {
+ .destroy = iommufd_vqueue_destroy,
+ },
#ifdef CONFIG_IOMMUFD_TEST
[IOMMUFD_OBJ_SELFTEST] = {
.destroy = iommufd_selftest_destroy,
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index a65153458a26..10d985aae9a8 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -170,3 +170,102 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd)
iommufd_put_object(ucmd->ictx, &viommu->obj);
return rc;
}
+
+void iommufd_vqueue_destroy(struct iommufd_object *obj)
+{
+ struct iommufd_vqueue *vqueue =
+ container_of(obj, struct iommufd_vqueue, obj);
+ struct iommufd_viommu *viommu = vqueue->viommu;
+
+ if (viommu->ops->vqueue_destroy)
+ viommu->ops->vqueue_destroy(vqueue);
+ iopt_unpin_pages(&viommu->hwpt->ioas->iopt, vqueue->addr,
+ vqueue->length);
+ refcount_dec(&viommu->obj.users);
+}
+
+int iommufd_vqueue_alloc_ioctl(struct iommufd_ucmd *ucmd)
+{
+ struct iommu_vqueue_alloc *cmd = ucmd->cmd;
+ struct iommufd_viommu *viommu;
+ struct iommufd_vqueue *vqueue;
+ struct page **pages;
+ int max_npages, i;
+ dma_addr_t end;
+ int rc;
+
+ if (cmd->flags || cmd->type == IOMMU_VQUEUE_TYPE_DEFAULT)
+ return -EOPNOTSUPP;
+ if (!cmd->addr || !cmd->length)
+ return -EINVAL;
+ if (check_add_overflow(cmd->addr, cmd->length - 1, &end))
+ return -EOVERFLOW;
+
+ max_npages = DIV_ROUND_UP(cmd->length, PAGE_SIZE);
+ pages = kcalloc(max_npages, sizeof(*pages), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+ viommu = iommufd_get_viommu(ucmd, cmd->viommu_id);
+ if (IS_ERR(viommu)) {
+ rc = PTR_ERR(viommu);
+ goto out_free;
+ }
+
+ if (!viommu->ops || !viommu->ops->vqueue_alloc) {
+ rc = -EOPNOTSUPP;
+ goto out_put_viommu;
+ }
+
+ /* Quick test on the base address */
+ if (!iommu_iova_to_phys(viommu->hwpt->common.domain, cmd->addr)) {
+ rc = -ENXIO;
+ goto out_put_viommu;
+ }
+
+ /*
+ * The underlying physical pages must be pinned to prevent them from
+ * being unmapped (via IOMMUFD_CMD_IOAS_UNMAP) during the life cycle
+ * of the vCMDQ object.
+ */
+ rc = iopt_pin_pages(&viommu->hwpt->ioas->iopt, cmd->addr, cmd->length,
+ pages, 0);
+ if (rc)
+ goto out_put_viommu;
+
+ /* Validate if the underlying physical pages are contiguous */
+ for (i = 1; i < max_npages && pages[i]; i++) {
+ if (page_to_pfn(pages[i]) == page_to_pfn(pages[i - 1]) + 1)
+ continue;
+ rc = -EFAULT;
+ goto out_unpin;
+ }
+
+ vqueue = viommu->ops->vqueue_alloc(viommu, cmd->type, cmd->index,
+ cmd->addr, cmd->length);
+ if (IS_ERR(vqueue)) {
+ rc = PTR_ERR(vqueue);
+ goto out_unpin;
+ }
+
+ vqueue->viommu = viommu;
+ refcount_inc(&viommu->obj.users);
+ vqueue->addr = cmd->addr;
+ vqueue->ictx = ucmd->ictx;
+ vqueue->length = cmd->length;
+ cmd->out_vqueue_id = vqueue->obj.id;
+ rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
+ if (rc)
+ iommufd_object_abort_and_destroy(ucmd->ictx, &vqueue->obj);
+ else
+ iommufd_object_finalize(ucmd->ictx, &vqueue->obj);
+ goto out_put_viommu;
+
+out_unpin:
+ iopt_unpin_pages(&viommu->hwpt->ioas->iopt, cmd->addr, cmd->length);
+out_put_viommu:
+ iommufd_put_object(ucmd->ictx, &viommu->obj);
+out_free:
+ kfree(pages);
+ return rc;
+}
--
2.43.0
