qtest: add test framework

The idea behind qtest is pretty simple.  Instead of executing a CPU via TCG or
KVM, rely on an external process to send events to the device model that the CPU
would normally generate.

qtest presents itself as an accelerator.  In addition, a new option is added to
establish a qtest server (-qtest) that takes a character device.  This is what
allows the external process to send CPU events to the device model.

qtest uses a simple line based protocol to send the events.  Documentation of
that protocol is in qtest.c.

I considered reusing the monitor for this job.  Adding interrupts would be a bit
difficult.  In addition, logging would also be difficult.

qtest has extensive logging support.  All protocol commands are logged with
time stamps using a new command line option (-qtest-log).  Logging is important
since ultimately, this is a feature for debugging.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index 662f571527..fe88939805 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2715,6 +2715,14 @@ the @var{simple} tracing backend.
 @end table
 ETEXI
 
+DEF("qtest", HAS_ARG, QEMU_OPTION_qtest,
+    "-qtest CHR      specify tracing options\n",
+    QEMU_ARCH_ALL)
+
+DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log,
+    "-qtest-log LOG  specify tracing options\n",
+    QEMU_ARCH_ALL)
+
 HXCOMM This is the last statement. Insert new options before this line!
 STEXI
 @end table