From f2333d5f9f9fd8e823bad7bf8804c9423b97eb08 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 1 Aug 2016 10:36:57 +0100 Subject: [PATCH] docs: document xenconsole startup protocol Signed-off-by: Wei Liu Acked-by: Ian Jackson --- docs/misc/console.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/docs/misc/console.txt b/docs/misc/console.txt index ed7b7956a6..16da805d0b 100644 --- a/docs/misc/console.txt +++ b/docs/misc/console.txt @@ -124,3 +124,9 @@ can only have one pv console with xenstored as backend (the stubdom could provide pv console backends to the hvm guest but then it would need another pv console connection for each console backend to export the pty to dom0). + +The xenconsole program supports a very simple protocol to notify parent about +its readiness. If xenconsole (the client) is exec'ed and has been given a fd +(normally the write end of a pipe) via --start-notify-fd option, it will +write 0x00 to that fd after connecting to the guest but before entering the +event loop. Parent can read from the read end of the fd to know the status. -- 2.39.5