Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 107 insertions, 0 deletions

diff --git a/linux-user/linux_loop.h b/linux-user/linux_loop.h
new file mode 100644
index 000000000..f80b96f1f
--- /dev/null
+++ b/linux-user/linux_loop.h
@@ -0,0 +1,107 @@
+/* Copied from 2.6.25 kernel headers to avoid problems on older hosts,
+ * and subsequently updated to match newer additions to the API.
+ */
+
+#ifndef LINUX_LOOP_H
+#define LINUX_LOOP_H
+
+/*
+ * include/linux/loop.h
+ *
+ * Written by Theodore Ts'o, 3/29/93.
+ *
+ * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
+ * permitted under the GNU General Public License.
+ */
+
+#define LO_NAME_SIZE	64
+#define LO_KEY_SIZE	32
+
+
+/*
+ * Loop flags
+ */
+enum {
+	LO_FLAGS_READ_ONLY	= 1,
+	LO_FLAGS_USE_AOPS	= 2,
+	LO_FLAGS_AUTOCLEAR	= 4,
+};
+
+#include <linux/version.h>
+#include <asm/posix_types.h>	/* for __kernel_old_dev_t */
+#include <asm/types.h>		/* for __u64 */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) /* This is a guess.  */
+#define __kernel_old_dev_t __kernel_dev_t
+#endif
+
+/* Backwards compatibility version */
+struct loop_info {
+	int		   lo_number;		/* ioctl r/o */
+	__kernel_old_dev_t lo_device; 		/* ioctl r/o */
+	unsigned long	   lo_inode; 		/* ioctl r/o */
+	__kernel_old_dev_t lo_rdevice; 		/* ioctl r/o */
+	int		   lo_offset;
+	int		   lo_encrypt_type;
+	int		   lo_encrypt_key_size; 	/* ioctl w/o */
+	int		   lo_flags;			/* ioctl r/o */
+	char		   lo_name[LO_NAME_SIZE];
+	unsigned char	   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+	unsigned long	   lo_init[2];
+	char		   reserved[4];
+};
+
+struct loop_info64 {
+	__u64		   lo_device;			/* ioctl r/o */
+	__u64		   lo_inode;			/* ioctl r/o */
+	__u64		   lo_rdevice;			/* ioctl r/o */
+	__u64		   lo_offset;
+	__u64		   lo_sizelimit;/* bytes, 0 == max available */
+	__u32		   lo_number;			/* ioctl r/o */
+	__u32		   lo_encrypt_type;
+	__u32		   lo_encrypt_key_size;		/* ioctl w/o */
+	__u32		   lo_flags;			/* ioctl r/o */
+	__u8		   lo_file_name[LO_NAME_SIZE];
+	__u8		   lo_crypt_name[LO_NAME_SIZE];
+	__u8		   lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
+	__u64		   lo_init[2];
+};
+
+/*
+ * Loop filter types
+ */
+
+#define LO_CRYPT_NONE		0
+#define LO_CRYPT_XOR		1
+#define LO_CRYPT_DES		2
+#define LO_CRYPT_FISH2		3    /* Twofish encryption */
+#define LO_CRYPT_BLOW		4
+#define LO_CRYPT_CAST128	5
+#define LO_CRYPT_IDEA		6
+#define LO_CRYPT_DUMMY		9
+#define LO_CRYPT_SKIPJACK	10
+#define LO_CRYPT_CRYPTOAPI	18
+#define MAX_LO_CRYPT		20
+
+/*
+ * IOCTL commands --- we will commandeer 0x4C ('L')
+ */
+
+#define LOOP_SET_FD		0x4C00
+#define LOOP_CLR_FD		0x4C01
+#define LOOP_SET_STATUS		0x4C02
+#define LOOP_GET_STATUS		0x4C03
+#define LOOP_SET_STATUS64	0x4C04
+#define LOOP_GET_STATUS64	0x4C05
+#define LOOP_CHANGE_FD		0x4C06
+#define LOOP_SET_CAPACITY       0x4C07
+#define LOOP_SET_DIRECT_IO      0x4C08
+#define LOOP_SET_BLOCK_SIZE     0x4C09
+#define LOOP_CONFIGURE          0x4C0A
+
+/* /dev/loop-control interface */
+#define LOOP_CTL_ADD            0x4C80
+#define LOOP_CTL_REMOVE         0x4C81
+#define LOOP_CTL_GET_FREE       0x4C82
+
+#endif