tree 66c051fac35849764818a47aa278d073af72b182
parent 8ca84a50e5b39487ea1de8809d0ee1c8474f6a5c
author Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> 1344515490 +0900
committer Rusty Russell <rusty@rustcorp.com.au> 1348810513 +0930

tools: Add guest trace agent as a user tool

This patch adds a user tool, "trace agent" for sending trace data of a guest to
a Host in low overhead. This agent has the following functions:
 - splice a page of ring-buffer to read_pipe without memory copying
 - splice the page from write_pipe to virtio-console without memory copying
 - write trace data to stdout by using -o option
 - controlled by start/stop orders from a Host

Changes in v2:
 - Cleanup (change fprintf() to pr_err() and an include guard)

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>