Re: [Qemu-devel] [PATCH 1/2] qtest: don't configure icount if qtest not allowed

[Paolo Bonzini <pbonzini@redhat.com>]

Il 17/10/2013 23:52, Michael S. Tsirkin ha scritto:
> This makes it possible to run bios under qtest

Alternatively, let's split qtest_init into a part for "-machine 
accel=qtest" and one for -qtest.

Also has the advantage of fixing an assertion with "qemu-system-x86_64 
-machine accel=qtest".

Paolo

-------------- 8< --------------------
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: [PATCH] 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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/sysemu/qtest.h b/include/sysemu/qtest.h
index 3927ebb..9b138e9 100644
--- a/include/sysemu/qtest.h
+++ b/include/sysemu/qtest.h
@@ -16,33 +16,23 @@
 
 #include "qemu-common.h"
 
-#if !defined(CONFIG_USER_ONLY)
 extern bool qtest_allowed;
-extern const char *qtest_chrdev;
-extern const char *qtest_log;
 
 static inline bool qtest_enabled(void)
 {
     return qtest_allowed;
 }
 
-static inline int qtest_available(void)
-{
-    return 1;
-}
-
 int qtest_init_accel(void);
 void qtest_init(const char *qtest_chrdev, const char *qtest_log);
-#else
-static inline bool qtest_enabled(void)
-{
-    return false;
-}
 
 static inline int qtest_available(void)
 {
+#ifdef CONFIG_POSIX
+    return 1;
+#else
     return 0;
-}
 #endif
+}
 
 #endif
diff --git a/qtest.c b/qtest.c
index 584c707..dcf1301 100644
--- a/qtest.c
+++ b/qtest.c
@@ -22,8 +22,6 @@
 
 #define MAX_IRQ 256
 
-const char *qtest_chrdev;
-const char *qtest_log;
 bool qtest_allowed;
 
 static DeviceState *irq_intercept_dev;
@@ -406,7 +404,7 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
 
         qtest_send_prefix(chr);
         qtest_send(chr, "OK\n");
-    } else if (strcmp(words[0], "clock_step") == 0) {
+    } else if (qtest_enabled() && strcmp(words[0], "clock_step") == 0) {
         int64_t ns;
 
         if (words[1]) {
@@ -417,7 +415,7 @@ static void qtest_process_command(CharDriverState *chr, gchar **words)
         qtest_clock_warp(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns);
         qtest_send_prefix(chr);
         qtest_send(chr, "OK %"PRIi64"\n", (int64_t)qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
-    } else if (strcmp(words[0], "clock_set") == 0) {
+    } else if (qtest_enabled() && strcmp(words[0], "clock_set") == 0) {
         int64_t ns;
 
         g_assert(words[1]);
@@ -502,13 +500,17 @@ static void qtest_event(void *opaque, int event)
     }
 }
 
-int qtest_init(void)
+int qtest_init_accel(void)
 {
-    CharDriverState *chr;
+    configure_icount("0");
 
-    g_assert(qtest_chrdev != NULL);
+    return 0;
+}
+
+void qtest_init(const char *qtest_chrdev, const char *qtest_log)
+{
+    CharDriverState *chr;
 
-    configure_icount("0");
     chr = qemu_chr_new("qtest", qtest_chrdev, NULL);
 
     qemu_chr_add_handlers(chr, qtest_can_read, qtest_read, qtest_event, chr);
@@ -525,6 +527,4 @@ int qtest_init(void)
     }
 
     qtest_chr = chr;
-
-    return 0;
 }
diff --git a/vl.c b/vl.c
index 983cdc6..568a6f5 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
@@ -4041,8 +4043,8 @@ 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();

> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  qtest.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/qtest.c b/qtest.c
> index 584c707..48e3288 100644
> --- a/qtest.c
> +++ b/qtest.c
> @@ -508,7 +508,9 @@ int qtest_init(void)
>  
>      g_assert(qtest_chrdev != NULL);
>  
> -    configure_icount("0");
> +    if (qtest_enabled()) {
> +        configure_icount("0");
> +    }
>      chr = qemu_chr_new("qtest", qtest_chrdev, NULL);
>  
>      qemu_chr_add_handlers(chr, qtest_can_read, qtest_read, qtest_event, chr);
>