diff options
Diffstat (limited to 'drivers/vfio/vfio_main.c')
| -rw-r--r-- | drivers/vfio/vfio_main.c | 122 |
1 files changed, 121 insertions, 1 deletions
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index a74c34232c03..fd5e969ab653 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -770,7 +770,7 @@ out_unlock: static const struct file_operations vfio_device_fops; /* true if the vfio_device has open_device() called but not close_device() */ -bool vfio_assert_device_open(struct vfio_device *device) +static bool vfio_assert_device_open(struct vfio_device *device) { return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); } @@ -1877,6 +1877,126 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); /* + * Pin contiguous user pages and return their associated host pages for local + * domain only. + * @device [in] : device + * @iova [in] : starting IOVA of user pages to be pinned. + * @npage [in] : count of pages to be pinned. This count should not + * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. + * @prot [in] : protection flags + * @pages[out] : array of host pages + * Return error or number of pages pinned. + * + * A driver may only call this function if the vfio_device was created + * by vfio_register_emulated_iommu_dev() due to vfio_container_pin_pages(). + */ +int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, + int npage, int prot, struct page **pages) +{ + /* group->container cannot change while a vfio device is open */ + if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device))) + return -EINVAL; + if (device->group->container) + return vfio_container_pin_pages(device->group->container, + device->group->iommu_group, + iova, npage, prot, pages); + if (device->iommufd_access) { + int ret; + + if (iova > ULONG_MAX) + return -EINVAL; + /* + * VFIO ignores the sub page offset, npages is from the start of + * a PAGE_SIZE chunk of IOVA. The caller is expected to recover + * the sub page offset by doing: + * pages[0] + (iova % PAGE_SIZE) + */ + ret = iommufd_access_pin_pages( + device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE), + npage * PAGE_SIZE, pages, + (prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0); + if (ret) + return ret; + return npage; + } + return -EINVAL; +} +EXPORT_SYMBOL(vfio_pin_pages); + +/* + * Unpin contiguous host pages for local domain only. + * @device [in] : device + * @iova [in] : starting address of user pages to be unpinned. + * @npage [in] : count of pages to be unpinned. This count should not + * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. + */ +void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) +{ + if (WARN_ON(!vfio_assert_device_open(device))) + return; + + if (device->group->container) { + vfio_container_unpin_pages(device->group->container, iova, + npage); + return; + } + if (device->iommufd_access) { + if (WARN_ON(iova > ULONG_MAX)) + return; + iommufd_access_unpin_pages(device->iommufd_access, + ALIGN_DOWN(iova, PAGE_SIZE), + npage * PAGE_SIZE); + return; + } +} +EXPORT_SYMBOL(vfio_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. + * + * @device [in] : VFIO device + * @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_device *device, dma_addr_t iova, void *data, + size_t len, bool write) +{ + if (!data || len <= 0 || !vfio_assert_device_open(device)) + return -EINVAL; + + if (device->group->container) + return vfio_container_dma_rw(device->group->container, iova, + data, len, write); + + if (device->iommufd_access) { + unsigned int flags = 0; + + if (iova > ULONG_MAX) + return -EINVAL; + + /* VFIO historically tries to auto-detect a kthread */ + if (!current->mm) + flags |= IOMMUFD_ACCESS_RW_KTHREAD; + if (write) + flags |= IOMMUFD_ACCESS_RW_WRITE; + return iommufd_access_rw(device->iommufd_access, iova, data, + len, flags); + } + return -EINVAL; +} +EXPORT_SYMBOL(vfio_dma_rw); + +/* * Module/class support */ static char *vfio_devnode(struct device *dev, umode_t *mode) |