diff options
Diffstat (limited to 'drivers/vfio/vfio.c')
| -rw-r--r-- | drivers/vfio/vfio.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 0bd77d6ea691..765e0e5d83ed 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1732,6 +1732,44 @@ struct vfio_group *vfio_group_get_external_user(struct file *filep) } EXPORT_SYMBOL_GPL(vfio_group_get_external_user); +/** + * External user API, exported by symbols to be linked dynamically. + * The external user passes in a device pointer + * to verify that: + * - A VFIO group is assiciated with the device; + * - IOMMU is set for the group. + * If both checks passed, vfio_group_get_external_user_from_dev() + * increments the container user counter to prevent the VFIO group + * from disposal before external user exits and returns the pointer + * to the VFIO group. + * + * When the external user finishes using the VFIO group, it calls + * vfio_group_put_external_user() to release the VFIO group and + * decrement the container user counter. + * + * @dev [in] : device + * Return error PTR or pointer to VFIO group. + */ + +struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev) +{ + struct vfio_group *group; + int ret; + + group = vfio_group_get_from_dev(dev); + if (!group) + return ERR_PTR(-ENODEV); + + ret = vfio_group_add_container_user(group); + if (ret) { + vfio_group_put(group); + return ERR_PTR(ret); + } + + return group; +} +EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev); + void vfio_group_put_external_user(struct vfio_group *group) { vfio_group_try_dissolve_container(group); @@ -1973,6 +2011,146 @@ err_unpin_pages: } EXPORT_SYMBOL(vfio_unpin_pages); +/* + * Pin a set of guest IOVA PFNs and return their associated host PFNs for a + * VFIO group. + * + * The caller needs to call vfio_group_get_external_user() or + * vfio_group_get_external_user_from_dev() prior to calling this interface, + * so as to prevent the VFIO group from disposal in the middle of the call. + * But it can keep the reference to the VFIO group for several calls into + * this interface. + * After finishing using of the VFIO group, the caller needs to release the + * VFIO group by calling vfio_group_put_external_user(). + * + * @group [in] : VFIO group + * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be pinned. + * @npage [in] : count of elements in user_iova_pfn array. + * This count should not be greater + * VFIO_PIN_PAGES_MAX_ENTRIES. + * @prot [in] : protection flags + * @phys_pfn [out] : array of host PFNs + * Return error or number of pages pinned. + */ +int vfio_group_pin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage, + int prot, unsigned long *phys_pfn) +{ + struct vfio_container *container; + struct vfio_iommu_driver *driver; + int ret; + + if (!group || !user_iova_pfn || !phys_pfn || !npage) + return -EINVAL; + + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) + return -E2BIG; + + container = group->container; + driver = container->iommu_driver; + if (likely(driver && driver->ops->pin_pages)) + ret = driver->ops->pin_pages(container->iommu_data, + user_iova_pfn, npage, + prot, phys_pfn); + else + ret = -ENOTTY; + + return ret; +} +EXPORT_SYMBOL(vfio_group_pin_pages); + +/* + * Unpin a set of guest IOVA PFNs for a VFIO group. + * + * The caller needs to call vfio_group_get_external_user() or + * vfio_group_get_external_user_from_dev() prior to calling this interface, + * so as to prevent the VFIO group from disposal in the middle of the call. + * But it can keep the reference to the VFIO group for several calls into + * this interface. + * After finishing using of the VFIO group, the caller needs to release the + * VFIO group by calling vfio_group_put_external_user(). + * + * @group [in] : vfio group + * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be unpinned. + * @npage [in] : count of elements in user_iova_pfn array. + * This count should not be greater than + * VFIO_PIN_PAGES_MAX_ENTRIES. + * Return error or number of pages unpinned. + */ +int vfio_group_unpin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage) +{ + struct vfio_container *container; + struct vfio_iommu_driver *driver; + int ret; + + if (!group || !user_iova_pfn || !npage) + return -EINVAL; + + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) + return -E2BIG; + + container = group->container; + driver = container->iommu_driver; + if (likely(driver && driver->ops->unpin_pages)) + ret = driver->ops->unpin_pages(container->iommu_data, + user_iova_pfn, npage); + else + ret = -ENOTTY; + + return ret; +} +EXPORT_SYMBOL(vfio_group_unpin_pages); + + +/* + * This interface allows the CPUs to perform some sort of virtual DMA on + * behalf of the device. + * + * CPUs read/write from/into a range of IOVAs pointing to user space memory + * into/from a kernel buffer. + * + * As the read/write of user space memory is conducted via the CPUs and is + * not a real device DMA, it is not necessary to pin the user space memory. + * + * The caller needs to call vfio_group_get_external_user() or + * vfio_group_get_external_user_from_dev() prior to calling this interface, + * so as to prevent the VFIO group from disposal in the middle of the call. + * But it can keep the reference to the VFIO group for several calls into + * this interface. + * After finishing using of the VFIO group, the caller needs to release the + * VFIO group by calling vfio_group_put_external_user(). + * + * @group [in] : VFIO group + * @user_iova [in] : base IOVA of a user space buffer + * @data [in] : pointer to kernel buffer + * @len [in] : kernel buffer length + * @write : indicate read or write + * Return error code on failure or 0 on success. + */ +int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova, + void *data, size_t len, bool write) +{ + struct vfio_container *container; + struct vfio_iommu_driver *driver; + int ret = 0; + + if (!group || !data || len <= 0) + return -EINVAL; + + container = group->container; + driver = container->iommu_driver; + + if (likely(driver && driver->ops->dma_rw)) + ret = driver->ops->dma_rw(container->iommu_data, + user_iova, data, len, write); + else + ret = -ENOTTY; + + return ret; +} +EXPORT_SYMBOL(vfio_dma_rw); + static int vfio_register_iommu_notifier(struct vfio_group *group, unsigned long *events, struct notifier_block *nb) |