qtest: split configuration of qtest accelerator and chardev

qtest uses the icount infrastructure to implement a test-driven vm_clock.  This
however is not necessary when using -qtest as a "probe" together with a normal
TCG-, KVM- or Xen-based virtual machine.  Hence, split out the call to
configure_icount into a new function that is called only for "-machine
accel=qtest"; and disable those commands when running with an accelerator
other than qtest.

This also fixes an assertion failure with "qemu-system-x86_64 -machine
accel=qtest" but no -qtest option.  This is a valid case, albeit somewhat
weird; nothing will happen in the VM but you'll still be able to
interact with the monitor or the GUI.

Now that qtest_init is not limited to an int(void) function, change
global variables that are not used outside qtest_init to arguments.

And finally, cleanup useless parts of include/sysemu/qtest.h.  The file
is not used at all for user-only emulation, and qtest is not available
on Win32 due to its usage of sigwait.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/vl.c b/vl.c
index 29e566fefa..60dbbcb347 100644
--- a/vl.c
+++ b/vl.c
@@ -2624,7 +2624,7 @@ 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 },
+    { "qtest", "QTest", qtest_available, qtest_init_accel, &qtest_allowed },
 };
 
 static int configure_accelerator(void)
@@ -2836,6 +2836,8 @@ int main(int argc, char **argv, char **envp)
     QEMUMachine *machine;
     const char *cpu_model;
     const char *vga_model = "none";
+    const char *qtest_chrdev = NULL;
+    const char *qtest_log = NULL;
     const char *pid_file = NULL;
     const char *incoming = NULL;
 #ifdef CONFIG_VNC
@@ -4043,8 +4045,8 @@ int main(int argc, char **argv, char **envp)
 
     configure_accelerator();
 
-    if (!qtest_enabled() && qtest_chrdev) {
-        qtest_init();
+    if (qtest_chrdev) {
+        qtest_init(qtest_chrdev, qtest_log);
     }
 
     machine_opts = qemu_get_machine_opts();