@@ -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
@@ -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");