Commit d7af80b2 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/zcrx: export zcrx via a file 



Add an option to wrap a zcrx instance into a file and expose it to the
user space. Currently, users can't do anything meaningful with the file,
but it'll be used in a next patch to import it into another io_uring
instance. It's implemented as a new op called ZCRX_CTRL_EXPORT for the
IORING_REGISTER_ZCRX_CTRL registration opcode.

Signed-off-by: default avatarDavid Wei <dw@davidwei.uk>
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 742cb2e1

include/uapi/linux/io_uring.h

+10 −1
Original line number Diff line number Diff line
@@ -1083,6 +1083,7 @@ struct io_uring_zcrx_ifq_reg { 


enum zcrx_ctrl_op {

	ZCRX_CTRL_FLUSH_RQ,

	ZCRX_CTRL_EXPORT,



	__ZCRX_CTRL_LAST,

};
@@ -1091,13 +1092,21 @@ struct zcrx_ctrl_flush_rq { 
	__u64		__resv[6];

};



struct zcrx_ctrl_export {

	__u32		zcrx_fd;

	__u32 		__resv1[11];

};



struct zcrx_ctrl {

	__u32	zcrx_id;

	__u32	op; /* see enum zcrx_ctrl_op */

	__u64	__resv[2];



	union {

		struct zcrx_ctrl_export		zc_export;

		struct zcrx_ctrl_flush_rq	zc_flush;

	};

};



#ifdef __cplusplus

}

io_uring/zcrx.c

+62 −6
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/netdevice.h>

#include <linux/rtnetlink.h>

#include <linux/skbuff_ref.h>

#include <linux/anon_inodes.h>



#include <net/page_pool/helpers.h>

#include <net/page_pool/memory_provider.h>
@@ -586,6 +587,15 @@ static void io_zcrx_scrub(struct io_zcrx_ifq *ifq) 
	}

}



static void zcrx_unregister(struct io_zcrx_ifq *ifq)

{

	if (refcount_dec_and_test(&ifq->user_refs)) {

		io_close_queue(ifq);

		io_zcrx_scrub(ifq);

	}

	io_put_zcrx_ifq(ifq);

}



struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx,

					    unsigned int id)

{
@@ -596,6 +606,55 @@ struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, 
	return ifq ? &ifq->region : NULL;

}



static int zcrx_box_release(struct inode *inode, struct file *file)

{

	struct io_zcrx_ifq *ifq = file->private_data;



	if (WARN_ON_ONCE(!ifq))

		return -EFAULT;

	zcrx_unregister(ifq);

	return 0;

}



static const struct file_operations zcrx_box_fops = {

	.owner		= THIS_MODULE,

	.release	= zcrx_box_release,

};



static int zcrx_export(struct io_ring_ctx *ctx, struct io_zcrx_ifq *ifq,

		       struct zcrx_ctrl *ctrl, void __user *arg)

{

	struct zcrx_ctrl_export *ce = &ctrl->zc_export;

	struct file *file;

	int fd = -1;



	if (!mem_is_zero(ce, sizeof(*ce)))

		return -EINVAL;

	fd = get_unused_fd_flags(O_CLOEXEC);

	if (fd < 0)

		return fd;



	ce->zcrx_fd = fd;

	if (copy_to_user(arg, ctrl, sizeof(*ctrl))) {

		put_unused_fd(fd);

		return -EFAULT;

	}



	refcount_inc(&ifq->refs);

	refcount_inc(&ifq->user_refs);



	file = anon_inode_create_getfile("[zcrx]", &zcrx_box_fops,

					 ifq, O_CLOEXEC, NULL);

	if (IS_ERR(file)) {

		put_unused_fd(fd);

		zcrx_unregister(ifq);

		return PTR_ERR(file);

	}



	fd_install(fd, file);

	return 0;

}



int io_register_zcrx_ifq(struct io_ring_ctx *ctx,

			  struct io_uring_zcrx_ifq_reg __user *arg)

{
@@ -742,12 +801,7 @@ void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx) 
		}

		if (!ifq)

			break;



		if (refcount_dec_and_test(&ifq->user_refs)) {

			io_close_queue(ifq);

			io_zcrx_scrub(ifq);

		}

		io_put_zcrx_ifq(ifq);

		zcrx_unregister(ifq);

	}



	xa_destroy(&ctx->zcrx_ctxs);
@@ -1028,6 +1082,8 @@ int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) 
	switch (ctrl.op) {

	case ZCRX_CTRL_FLUSH_RQ:

		return zcrx_flush_rq(ctx, zcrx, &ctrl);

	case ZCRX_CTRL_EXPORT:

		return zcrx_export(ctx, zcrx, &ctrl, arg);

	}



	return -EOPNOTSUPP;