[Qemu-devel] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Qemu-devel] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Chen Gang]

When failure occurs, it need use "return -1" instead of exit(1), so can
let upper caller has chance to print failure information, too.

For simplify thinking, in xen_hvm_init(), also use '-1' instead of all
'-errno', since all related upper callers always exit(1) for failure.

It is not a normal function, it does not release related resources when
return -1, so need give related comments for it.


It passes common check:

  "./configure --enable-xen && make && make check"
  "echo $? == 0"


Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
---
 xen-hvm.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/xen-hvm.c b/xen-hvm.c
index 0d09940..2c6285d 100644
--- a/xen-hvm.c
+++ b/xen-hvm.c
@@ -978,6 +978,7 @@ static void xen_wakeup_notifier(Notifier *notifier, void *data)
     xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
 }
 
+/* return 0 means OK, or -1 means critical issue -- will exit(1) */
 int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
                  MemoryRegion **ram_memory)
 {
@@ -991,15 +992,13 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
     state->xce_handle = xen_xc_evtchn_open(NULL, 0);
     if (state->xce_handle == XC_HANDLER_INITIAL_VALUE) {
         perror("xen: event channel open");
-        g_free(state);
-        return -errno;
+        return -1;
     }
 
     state->xenstore = xs_daemon_open();
     if (state->xenstore == NULL) {
         perror("xen: xenstore open");
-        g_free(state);
-        return -errno;
+        return -1;
     }
 
     state->exit.notify = xen_exit_notifier;
@@ -1069,7 +1068,7 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
     /* Initialize backend core & drivers */
     if (xen_be_init() != 0) {
         fprintf(stderr, "%s: xen backend core setup failed\n", __FUNCTION__);
-        exit(1);
+        return -1;
     }
     xen_be_register("console", &xen_console_ops);
     xen_be_register("vkbd", &xen_kbdmouse_ops);
-- 
1.9.3

Re: [Qemu-devel] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Stefano Stabellini]

On Thu, 4 Sep 2014, Chen Gang wrote:
> When failure occurs, it need use "return -1" instead of exit(1), so can
> let upper caller has chance to print failure information, too.
> 
> For simplify thinking, in xen_hvm_init(), also use '-1' instead of all
> '-errno', since all related upper callers always exit(1) for failure.
> 
> It is not a normal function, it does not release related resources when
> return -1, so need give related comments for it.
> 
> 
> It passes common check:
> 
>   "./configure --enable-xen && make && make check"
>   "echo $? == 0"
> 
> 
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>


>  xen-hvm.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/xen-hvm.c b/xen-hvm.c
> index 0d09940..2c6285d 100644
> --- a/xen-hvm.c
> +++ b/xen-hvm.c
> @@ -978,6 +978,7 @@ static void xen_wakeup_notifier(Notifier *notifier, void *data)
>      xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
>  }
>  
> +/* return 0 means OK, or -1 means critical issue -- will exit(1) */
>  int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
>                   MemoryRegion **ram_memory)
>  {
> @@ -991,15 +992,13 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
>      state->xce_handle = xen_xc_evtchn_open(NULL, 0);
>      if (state->xce_handle == XC_HANDLER_INITIAL_VALUE) {
>          perror("xen: event channel open");
> -        g_free(state);
> -        return -errno;
> +        return -1;
>      }
>  
>      state->xenstore = xs_daemon_open();
>      if (state->xenstore == NULL) {
>          perror("xen: xenstore open");
> -        g_free(state);
> -        return -errno;
> +        return -1;
>      }
>  
>      state->exit.notify = xen_exit_notifier;
> @@ -1069,7 +1068,7 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
>      /* Initialize backend core & drivers */
>      if (xen_be_init() != 0) {
>          fprintf(stderr, "%s: xen backend core setup failed\n", __FUNCTION__);
> -        exit(1);
> +        return -1;
>      }
>      xen_be_register("console", &xen_console_ops);
>      xen_be_register("vkbd", &xen_kbdmouse_ops);
> -- 
> 1.9.3
> 

Re: [Qemu-devel] [Qemu-trivial] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Michael Tokarev]

Applied to -trivial, after fixing the commit message to be
just a bit more english-like.  Thank you!

/mjt

Re: [Qemu-devel] [Qemu-trivial] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Chen Gang]

On 9/15/14 21:01, Michael Tokarev wrote:
> Applied to -trivial, after fixing the commit message to be
> just a bit more english-like.  Thank you!
> 

OK, thank you for your work.

Next, I shall do something related microblaze under Qemu to let it run
for microblaze gcc/binutils test, hope I can find additonal patches for
it.


Thanks.
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed

Re: [Qemu-devel] [Qemu-trivial] [PATCH v2] xen-hvm.c: Always return -1 when failure occurs in xen_hvm_init()

[Chen Gang]

On 9/15/14 21:01, Michael Tokarev wrote:
> Applied to -trivial, after fixing the commit message to be
> just a bit more english-like.  Thank you!
> 

OK, thank you for your work.

Next, I shall do something related microblaze under Qemu to let it run
for microblaze gcc/binutils test, hope I can find additional patches for
it.


Thanks.
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed