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

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Oct 18, 2013 at 01:51:11PM +0200, Paolo Bonzini wrote:
> 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>

Reviewed-by: Michael S. Tsirkin <mst@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);
> >