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, 9 insertions, 1 deletions

diff --git a/vl.c b/vl.c
index 0fccf50a5d..e575401d29 100644
--- a/vl.c
+++ b/vl.c
@@ -152,6 +152,7 @@ int main(int argc, char **argv)
 #ifdef CONFIG_VIRTFS
 #include "fsdev/qemu-fsdev.h"
 #endif
+#include "qtest.h"
 
 #include "disas.h"
 
@@ -1312,7 +1313,7 @@ int qemu_shutdown_requested(void)
 
 void qemu_kill_report(void)
 {
-    if (shutdown_signal != -1) {
+    if (!qtest_enabled() && shutdown_signal != -1) {
         fprintf(stderr, "qemu: terminating on signal %d", shutdown_signal);
         if (shutdown_pid == 0) {
             /* This happens for eg ^C at the terminal, so it's worth
@@ -2098,6 +2099,7 @@ static struct {
     { "tcg", "tcg", tcg_available, tcg_init, &tcg_allowed },
     { "xen", "Xen", xen_available, xen_init, &xen_allowed },
     { "kvm", "KVM", kvm_available, kvm_init, &kvm_allowed },
+    { "qtest", "QTest", qtest_available, qtest_init, &qtest_allowed },
 };
 
 static int configure_accelerator(void)
@@ -3181,6 +3183,12 @@ int main(int argc, char **argv, char **envp)
                     fclose(fp);
                     break;
                 }
+            case QEMU_OPTION_qtest:
+                qtest_chrdev = optarg;
+                break;
+            case QEMU_OPTION_qtest_log:
+                qtest_log = optarg;
+                break;
             default:
                 os_parse_cmd_args(popt->index, optarg);
             }