diff options
| -rw-r--r-- | drivers/iommu/iommufd/Kconfig | 20 | ||||
| -rw-r--r-- | drivers/iommu/iommufd/main.c | 36 |
2 files changed, 56 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig index 871244f2443f..8306616b6d81 100644 --- a/drivers/iommu/iommufd/Kconfig +++ b/drivers/iommu/iommufd/Kconfig @@ -12,6 +12,26 @@ config IOMMUFD If you don't know what to do here, say N. if IOMMUFD +config IOMMUFD_VFIO_CONTAINER + bool "IOMMUFD provides the VFIO container /dev/vfio/vfio" + depends on VFIO && !VFIO_CONTAINER + default VFIO && !VFIO_CONTAINER + help + IOMMUFD will provide /dev/vfio/vfio instead of VFIO. This relies on + IOMMUFD providing compatibility emulation to give the same ioctls. + It provides an option to build a kernel with legacy VFIO components + removed. + + IOMMUFD VFIO container emulation is known to lack certain features + of the native VFIO container, such as no-IOMMU support, peer-to-peer + DMA mapping, PPC IOMMU support, as well as other potentially + undiscovered gaps. This option is currently intended for the + purpose of testing IOMMUFD with unmodified userspace supporting VFIO + and making use of the Type1 VFIO IOMMU backend. General purpose + enabling of this option is currently discouraged. + + Unless testing IOMMUFD, say N here. + config IOMMUFD_TEST bool "IOMMU Userspace API Test support" depends on DEBUG_KERNEL diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index bcb463e58100..083e6fcbe10a 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -18,6 +18,7 @@ #include <uapi/linux/iommufd.h> #include <linux/iommufd.h> +#include "io_pagetable.h" #include "iommufd_private.h" #include "iommufd_test.h" @@ -25,6 +26,7 @@ struct iommufd_object_ops { void (*destroy)(struct iommufd_object *obj); }; static const struct iommufd_object_ops iommufd_object_ops[]; +static struct miscdevice vfio_misc_dev; struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, @@ -170,6 +172,16 @@ static int iommufd_fops_open(struct inode *inode, struct file *filp) if (!ictx) return -ENOMEM; + /* + * For compatibility with VFIO when /dev/vfio/vfio is opened we default + * to the same rlimit accounting as vfio uses. + */ + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER) && + filp->private_data == &vfio_misc_dev) { + ictx->account_mode = IOPT_PAGES_ACCOUNT_MM; + pr_info_once("IOMMUFD is providing /dev/vfio/vfio, not VFIO.\n"); + } + xa_init_flags(&ictx->objects, XA_FLAGS_ALLOC1 | XA_FLAGS_ACCOUNT); ictx->file = filp; filp->private_data = ictx; @@ -400,6 +412,15 @@ static struct miscdevice iommu_misc_dev = { .mode = 0660, }; + +static struct miscdevice vfio_misc_dev = { + .minor = VFIO_MINOR, + .name = "vfio", + .fops = &iommufd_fops, + .nodename = "vfio/vfio", + .mode = 0666, +}; + static int __init iommufd_init(void) { int ret; @@ -407,18 +428,33 @@ static int __init iommufd_init(void) ret = misc_register(&iommu_misc_dev); if (ret) return ret; + + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) { + ret = misc_register(&vfio_misc_dev); + if (ret) + goto err_misc; + } iommufd_test_init(); return 0; +err_misc: + misc_deregister(&iommu_misc_dev); + return ret; } static void __exit iommufd_exit(void) { iommufd_test_exit(); + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) + misc_deregister(&vfio_misc_dev); misc_deregister(&iommu_misc_dev); } module_init(iommufd_init); module_exit(iommufd_exit); +#if IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER) +MODULE_ALIAS_MISCDEV(VFIO_MINOR); +MODULE_ALIAS("devname:vfio/vfio"); +#endif MODULE_DESCRIPTION("I/O Address Space Management for passthrough devices"); MODULE_LICENSE("GPL"); |