virtio-9p: Add a virtio 9p device to qemu

This patch doesn't implement the 9p protocol handling
code. It adds a simple device which dump the protocol data.

[jvrao@linux.vnet.ibm.com: Little-Endian to host format conversion]
[aneesh.kumar@linux.vnet.ibm.com: Multiple-mounts support]

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/virtio-9p.h b/hw/virtio-9p.h
new file mode 100644
index 0000000..b95dbe4
--- /dev/null
+++ b/hw/virtio-9p.h
@@ -0,0 +1,166 @@
+#ifndef _QEMU_VIRTIO_9P_H
+#define _QEMU_VIRTIO_9P_H
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <utime.h>
+
+#include "file-op-9p.h"
+
+/* The feature bitmap for virtio 9P */
+/* The mount point is specified in a config variable */
+#define VIRTIO_9P_MOUNT_TAG 0
+
+enum {
+    P9_TVERSION = 100,
+    P9_RVERSION,
+    P9_TAUTH = 102,
+    P9_RAUTH,
+    P9_TATTACH = 104,
+    P9_RATTACH,
+    P9_TERROR = 106,
+    P9_RERROR,
+    P9_TFLUSH = 108,
+    P9_RFLUSH,
+    P9_TWALK = 110,
+    P9_RWALK,
+    P9_TOPEN = 112,
+    P9_ROPEN,
+    P9_TCREATE = 114,
+    P9_RCREATE,
+    P9_TREAD = 116,
+    P9_RREAD,
+    P9_TWRITE = 118,
+    P9_RWRITE,
+    P9_TCLUNK = 120,
+    P9_RCLUNK,
+    P9_TREMOVE = 122,
+    P9_RREMOVE,
+    P9_TSTAT = 124,
+    P9_RSTAT,
+    P9_TWSTAT = 126,
+    P9_RWSTAT,
+};
+
+
+/* qid.types */
+enum {
+    P9_QTDIR = 0x80,
+    P9_QTAPPEND = 0x40,
+    P9_QTEXCL = 0x20,
+    P9_QTMOUNT = 0x10,
+    P9_QTAUTH = 0x08,
+    P9_QTTMP = 0x04,
+    P9_QTSYMLINK = 0x02,
+    P9_QTLINK = 0x01,
+    P9_QTFILE = 0x00,
+};
+
+#define P9_NOTAG    (u16)(~0)
+#define P9_NOFID    (u32)(~0)
+#define P9_MAXWELEM 16
+
+typedef struct V9fsPDU V9fsPDU;
+
+struct V9fsPDU
+{
+    uint32_t size;
+    uint16_t tag;
+    uint8_t id;
+    VirtQueueElement elem;
+    QLIST_ENTRY(V9fsPDU) next;
+};
+
+
+/* FIXME
+ * 1) change user needs to set groups and stuff
+ */
+
+/* from Linux's linux/virtio_9p.h */
+
+/* The ID for virtio console */
+#define VIRTIO_ID_9P    9
+#define MAX_REQ         128
+#define MAX_TAG_LEN     32
+
+#define BUG_ON(cond) assert(!(cond))
+
+typedef struct V9fsFidState V9fsFidState;
+
+typedef struct V9fsString
+{
+    int16_t size;
+    char *data;
+} V9fsString;
+
+typedef struct V9fsQID
+{
+    int8_t type;
+    int32_t version;
+    int64_t path;
+} V9fsQID;
+
+typedef struct V9fsStat
+{
+    int16_t size;
+    int16_t type;
+    int32_t dev;
+    V9fsQID qid;
+    int32_t mode;
+    int32_t atime;
+    int32_t mtime;
+    int64_t length;
+    V9fsString name;
+    V9fsString uid;
+    V9fsString gid;
+    V9fsString muid;
+    /* 9p2000.u */
+    V9fsString extension;
+   int32_t n_uid;
+    int32_t n_gid;
+    int32_t n_muid;
+} V9fsStat;
+
+struct V9fsFidState
+{
+    int32_t fid;
+    V9fsString path;
+    int fd;
+    DIR *dir;
+    uid_t uid;
+    V9fsFidState *next;
+};
+
+typedef struct V9fsState
+{
+    VirtIODevice vdev;
+    VirtQueue *vq;
+    V9fsPDU pdus[MAX_REQ];
+    QLIST_HEAD(, V9fsPDU) free_list;
+    V9fsFidState *fid_list;
+    FileOperations *ops;
+    FsContext ctx;
+    uint16_t tag_len;
+    uint8_t *tag;
+    size_t config_size;
+} V9fsState;
+
+struct virtio_9p_config
+{
+    /* number of characters in tag */
+    uint16_t tag_len;
+    /* Variable size tag name */
+    uint8_t tag[0];
+} __attribute__((packed));
+
+extern size_t pdu_packunpack(void *addr, struct iovec *sg, int sg_count,
+                            size_t offset, size_t size, int pack);
+
+static inline size_t do_pdu_unpack(void *dst, struct iovec *sg, int sg_count,
+                        size_t offset, size_t size)
+{
+    return pdu_packunpack(dst, sg, sg_count, offset, size, 0);
+}
+
+#endif