hw/9pfs: Introduce tracing for 9p pdu handlers

Plan is to replace the existing debug infrastructure with Qemu tracing
infrastructure so that user can dynamically enable/disable trace events and
therefore a meaningful trace log can be generated which can be further
filtered using an analysis script.

Note: Because of current simpletrace limitations, the trace events are
logging at max 6 args, however, once the more args are supported, we can
change trace events to log more info as well. Also, This initial patch only
provides a replacement for existing debug infra. More trace events to be
added later for newly added handlers and sub-routines.
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

trace-events

@@ -538,3 +538,49 @@ esp_mem_writeb_cmd_ensel(uint32_t val) "Enable selection (%2.2x)"
 # monitor.c
 handle_qmp_command(void *mon, const char *cmd_name) "mon %p cmd_name \"%s\""
 monitor_protocol_emitter(void *mon) "mon %p"
+
+# hw/9pfs/virtio-9p.c
+complete_pdu(uint16_t tag, uint8_t id, int err) "tag %d id %d err %d"
+v9fs_version(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s"
+v9fs_version_return(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s"
+v9fs_attach(uint16_t tag, uint8_t id, int32_t fid, int32_t afid, char* uname, char* aname) "tag %d id %d fid %d afid %d aname %s"
+v9fs_attach_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d type %d version %d path %"PRId64""
+v9fs_stat(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_stat_return(uint16_t tag, uint8_t id, int32_t mode, int32_t atime, int32_t mtime, int64_t length) "tag %d id %d stat={mode %d atime %d mtime %d length %"PRId64"}"
+v9fs_getattr(uint16_t tag, uint8_t id, int32_t fid, uint64_t request_mask) "tag %d id %d fid %d request_mask %"PRIu64""
+v9fs_getattr_return(uint16_t tag, uint8_t id, uint64_t result_mask, uint32_t mode, uint32_t uid, uint32_t gid) "tag %d id %d getattr={result_mask %"PRId64" mode %u uid %u gid %u}"
+v9fs_walk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, uint16_t nwnames) "tag %d id %d fid %d newfid %d nwnames %d"
+v9fs_walk_return(uint16_t tag, uint8_t id, uint16_t nwnames, void* qids) "tag %d id %d nwnames %d qids %p"
+v9fs_open(uint16_t tag, uint8_t id, int32_t fid, int32_t mode) "tag %d id %d fid %d mode %d"
+v9fs_open_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_lcreate(uint16_t tag, uint8_t id, int32_t dfid, int32_t flags, int32_t mode, uint32_t gid) "tag %d id %d dfid %d flags %d mode %d gid %u"
+v9fs_lcreate_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int32_t iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_fsync(uint16_t tag, uint8_t id, int32_t fid, int datasync) "tag %d id %d fid %d datasync %d"
+v9fs_clunk(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_read(uint16_t tag, uint8_t id, int32_t fid, int64_t off, int32_t max_count) "tag %d id %d fid %d off %"PRId64" max_count %d"
+v9fs_read_return(uint16_t tag, uint8_t id, int32_t count, ssize_t err) "tag %d id %d count %d err %zd"
+v9fs_readdir(uint16_t tag, uint8_t id, int32_t fid, int64_t offset, int32_t max_count) "tag %d id %d fid %d offset %"PRId64" max_count %d"
+v9fs_readdir_return(uint16_t tag, uint8_t id, int32_t count, ssize_t retval) "tag %d id %d count %d retval %zd"
+v9fs_write(uint16_t tag, uint8_t id, int32_t fid, int64_t off, int32_t count, int cnt) "tag %d id %d fid %d off %"PRId64" count %d cnt %d"
+v9fs_write_return(uint16_t tag, uint8_t id, int32_t total, ssize_t err) "tag %d id %d total %d err %zd"
+v9fs_create(uint16_t tag, uint8_t id, int32_t fid, char* name, int32_t perm, int8_t mode) "tag %d id %d fid %d name %s perm %d mode %d"
+v9fs_create_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int iounit) "tag %d id %d qid={type %d version %d path %"PRId64"} iounit %d"
+v9fs_symlink(uint16_t tag, uint8_t id, int32_t fid,  char* name, char* symname, uint32_t gid) "tag %d id %d fid %d name %s symname %s gid %u"
+v9fs_symlink_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_flush(uint16_t tag, uint8_t id, int16_t flush_tag) "tag %d id %d flush_tag %d"
+v9fs_link(uint16_t tag, uint8_t id, int32_t dfid, int32_t oldfid, char* name) "tag %d id %d dfid %d oldfid %d name %s"
+v9fs_remove(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_wstat(uint16_t tag, uint8_t id, int32_t fid, int32_t mode, int32_t atime, int32_t mtime) "tag %d id %d fid %d stat={mode %d atime %d mtime}"
+v9fs_mknod(uint16_t tag, uint8_t id, int32_t fid, int mode, int major, int minor) "tag %d id %d fid %d mode %d major %d minor %d"
+v9fs_mknod_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_lock(uint16_t tag, uint8_t id, int32_t fid, uint8_t type, uint64_t start, uint64_t length) "tag %d id %d fid %d type %d start %"PRIu64" length %"PRIu64""
+v9fs_lock_return(uint16_t tag, uint8_t id, int8_t status) "tag %d id %d status %d"
+v9fs_getlock(uint16_t tag, uint8_t id, int32_t fid, uint8_t type, uint64_t start, uint64_t length)"tag %d id %d fid %d type %d start %"PRIu64" length %"PRIu64""
+v9fs_getlock_return(uint16_t tag, uint8_t id, uint8_t type, uint64_t start, uint64_t length, uint32_t proc_id) "tag %d id %d type %d start %"PRIu64" length %"PRIu64" proc_id %u"
+v9fs_mkdir(uint16_t tag, uint8_t id, int32_t fid, char* name, int mode, uint32_t gid) "tag %d id %d fid %d name %s mode %d"
+v9fs_mkdir_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int err) "tag %d id %d qid={type %d version %d path %"PRId64"}"
+v9fs_xattrwalk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, char* name) "tag %d id %d fid %d newfid %d name %s"
+v9fs_xattrwalk_return(uint16_t tag, uint8_t id, int64_t size) "tag %d id %d size %"PRId64""
+v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, int64_t size, int flags) "tag %d id %d fid %d name %s size %"PRId64" flags %d"
+v9fs_readlink(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
+v9fs_readlink_return(uint16_t tag, uint8_t id, char* target) "tag %d id %d name %s"