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From: Richard <judicator3@gmail.com>
To: xen-devel@lists.sourceforge.net
Subject: console driver - How domain0 processes console messages ?
Date: Wed, 16 Feb 2005 01:10:26 -0500	[thread overview]
Message-ID: <a146ff9b05021522102e311f77@mail.gmail.com> (raw)

Hello,

I am trying to undestand how the console driver works.
The files of interests are:
1.) drivers/xen/console/console.c
2.) arch/xen/kernel/ctrl_if.c

That is what I undestand so far. When an unpriveleged domain (say
domain1) wants to write to the console, the following happens:

1.) A function like kcons_write() is invoked to write the string to a
buffer "wbuf".
2.) Function __xencons_tx_flush() is  called to packet the characters
in the buffer "wbuf" into messages of type "ctrl_msg_t".
3.) A function like ctrl_if_send_message_noblock() is then called to
place the messages "ctrl_msg_t" into the communication ring that is
shared between dom1 and dom0.
4.) Function ctrl_if_notify_controller() is then called to send an
event notification to  domain0

Steps 1 to 4 occur in domain1 (the unprivileged domain). Now at the
over end of the event channel, I am trying to figure out where in
domain0 the event notification is being received and how it is being
processed. I am trying to undestand how domain0 processes console
messages  (i.e messages with type CMSG_CONSOLE and subtype
CMSG_CONSOLE_DATA).

Thanks
Richard


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             reply	other threads:[~2005-02-16  6:10 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-02-16  6:10 Richard [this message]
2005-02-16  7:54 ` console driver - How domain0 processes console messages ? Andrew Warfield
2005-02-16  8:38   ` Richard
2005-02-16  9:35     ` Andrew Warfield
2005-02-17  1:26       ` Anthony Liguori
2005-02-21  3:04         ` Richard
2005-02-16  8:38   ` aq
     [not found]     ` <eacc82a405021600562ed346d2@mail.gmail.com>
2005-02-16  8:57       ` Andrew Warfield

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