qemu-log: default to stderr for logging output

Switch the default for qemu_log logging output from "/tmp/qemu.log"
to stderr. This is an incompatible change in some sense, but logging
is mostly used for debugging purposes so it shouldn't affect production
use. The previous behaviour can be obtained by adding "-D /tmp/qemu.log"
to the command line.

This change requires us to:
 * update all the documentation/help text (we take the opportunity
   to smooth out minor inconsistencies between the phrasing in
   linux-user/bsd-user/system help messages)
 * make linux-user and bsd-user defer to qemu-log for the default
   logging destination rather than overriding it themselves
 * ensure that all logfile closing is done via qemu_log_close()
   and that that function doesn't close stderr
as well as the obvious change to the behaviour of do_qemu_set_log()
when no logfile name has been specified.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1361901160-28729-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tcg/tci/README b/tcg/tci/README
index 6ac1ac99d6..dc57f076b5 100644
--- a/tcg/tci/README
+++ b/tcg/tci/README
@@ -52,7 +52,7 @@ The only difference from running QEMU with TCI to running without TCI
 should be speed. Especially during development of TCI, it was very
 useful to compare runs with and without TCI. Create /tmp/qemu.log by
 
-        qemu-system-i386 -d in_asm,op_opt,cpu -singlestep
+        qemu-system-i386 -d in_asm,op_opt,cpu -D /tmp/qemu.log -singlestep
 
 once with interpreter and once without interpreter and compare the resulting
 qemu.log files. This is also useful to see the effects of additional