diff mbox series

[PATCH-for-5.1,v2,1/1] accel/xen: Fix xen_enabled() behavior on target-agnostic objects

Message ID 20200804074930.13104-2-philmd@redhat.com
State New
Headers show
Series accel/xen: Fix xen_enabled() behavior on target-agnostic objects | expand

Commit Message

Philippe Mathieu-Daudé Aug. 4, 2020, 7:49 a.m. UTC
CONFIG_XEN is generated by configure and stored in "config-target.h",
which is (obviously) only include for target-specific objects.
This is a problem for target-agnostic objects as CONFIG_XEN is never
defined and xen_enabled() is always inlined as 'false'.

Fix by following the KVM schema, defining CONFIG_XEN_IS_POSSIBLE
when we don't know to force the call of the non-inlined function,
returning the xen_allowed boolean.

Fixes: da278d58a092 ("accel: Move Xen accelerator code under accel/xen/")
Reported-by: Paul Durrant <pdurrant@amazon.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/sysemu/xen.h   | 18 ++++++++++++++----
 accel/stubs/xen-stub.c |  2 ++
 accel/xen/xen-all.c    |  7 +------
 3 files changed, 17 insertions(+), 10 deletions(-)

Comments

Paul Durrant Aug. 4, 2020, 7:57 a.m. UTC | #1
> -----Original Message-----
> From: Philippe Mathieu-Daudé <philmd@redhat.com>
> Sent: 04 August 2020 08:50
> To: qemu-devel@nongnu.org
> Cc: Peter Maydell <peter.maydell@linaro.org>; Anthony Perard <anthony.perard@citrix.com>; Paolo
> Bonzini <pbonzini@redhat.com>; Stefano Stabellini <sstabellini@kernel.org>; xen-
> devel@lists.xenproject.org; Paul Durrant <paul@xen.org>; Philippe Mathieu-Daudé <philmd@redhat.com>;
> Paul Durrant <pdurrant@amazon.com>
> Subject: [PATCH-for-5.1 v2 1/1] accel/xen: Fix xen_enabled() behavior on target-agnostic objects
> 
> CONFIG_XEN is generated by configure and stored in "config-target.h",
> which is (obviously) only include for target-specific objects.
> This is a problem for target-agnostic objects as CONFIG_XEN is never
> defined and xen_enabled() is always inlined as 'false'.
> 
> Fix by following the KVM schema, defining CONFIG_XEN_IS_POSSIBLE
> when we don't know to force the call of the non-inlined function,
> returning the xen_allowed boolean.
> 
> Fixes: da278d58a092 ("accel: Move Xen accelerator code under accel/xen/")
> Reported-by: Paul Durrant <pdurrant@amazon.com>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  include/sysemu/xen.h   | 18 ++++++++++++++----
>  accel/stubs/xen-stub.c |  2 ++
>  accel/xen/xen-all.c    |  7 +------
>  3 files changed, 17 insertions(+), 10 deletions(-)
> 
> diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
> index 1ca292715e..2c2c429ea8 100644
> --- a/include/sysemu/xen.h
> +++ b/include/sysemu/xen.h
> @@ -8,9 +8,19 @@
>  #ifndef SYSEMU_XEN_H
>  #define SYSEMU_XEN_H
> 
> -#ifdef CONFIG_XEN
> +#ifdef NEED_CPU_H
> +# ifdef CONFIG_XEN
> +#  define CONFIG_XEN_IS_POSSIBLE
> +# endif
> +#else
> +# define CONFIG_XEN_IS_POSSIBLE
> +#endif
> 
> -bool xen_enabled(void);
> +#ifdef CONFIG_XEN_IS_POSSIBLE
> +
> +extern bool xen_allowed;
> +
> +#define xen_enabled()           (xen_allowed)

Can this not move ahead of the #ifdef now (since xen_allowed is present in both xen-stub and xen-all)? I think this is what Peter was saying in his option '(2)'.

  Paul

> 
>  #ifndef CONFIG_USER_ONLY
>  void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
> @@ -18,7 +28,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>                     struct MemoryRegion *mr, Error **errp);
>  #endif
> 
> -#else /* !CONFIG_XEN */
> +#else /* !CONFIG_XEN_IS_POSSIBLE */
> 
>  #define xen_enabled() 0
>  #ifndef CONFIG_USER_ONLY
> @@ -33,6 +43,6 @@ static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>  }
>  #endif
> 
> -#endif /* CONFIG_XEN */
> +#endif /* CONFIG_XEN_IS_POSSIBLE */
> 
>  #endif
> diff --git a/accel/stubs/xen-stub.c b/accel/stubs/xen-stub.c
> index dcca4e678a..8ae658acff 100644
> --- a/accel/stubs/xen-stub.c
> +++ b/accel/stubs/xen-stub.c
> @@ -9,6 +9,8 @@
>  #include "hw/xen/xen.h"
>  #include "qapi/qapi-commands-misc.h"
> 
> +bool xen_allowed;
> +
>  void xenstore_store_pv_console_info(int i, Chardev *chr)
>  {
>  }
> diff --git a/accel/xen/xen-all.c b/accel/xen/xen-all.c
> index 0c24d4b191..60b971d0a8 100644
> --- a/accel/xen/xen-all.c
> +++ b/accel/xen/xen-all.c
> @@ -32,12 +32,7 @@
>      do { } while (0)
>  #endif
> 
> -static bool xen_allowed;
> -
> -bool xen_enabled(void)
> -{
> -    return xen_allowed;
> -}
> +bool xen_allowed;
> 
>  xc_interface *xen_xc;
>  xenforeignmemory_handle *xen_fmem;
> --
> 2.21.3
Philippe Mathieu-Daudé Aug. 4, 2020, 8:34 a.m. UTC | #2
Hi Paul,

On 8/4/20 9:57 AM, Paul Durrant wrote:
>> -----Original Message-----
>> From: Philippe Mathieu-Daudé <philmd@redhat.com>
>> Sent: 04 August 2020 08:50
>> To: qemu-devel@nongnu.org
>> Cc: Peter Maydell <peter.maydell@linaro.org>; Anthony Perard <anthony.perard@citrix.com>; Paolo
>> Bonzini <pbonzini@redhat.com>; Stefano Stabellini <sstabellini@kernel.org>; xen-
>> devel@lists.xenproject.org; Paul Durrant <paul@xen.org>; Philippe Mathieu-Daudé <philmd@redhat.com>;
>> Paul Durrant <pdurrant@amazon.com>
>> Subject: [PATCH-for-5.1 v2 1/1] accel/xen: Fix xen_enabled() behavior on target-agnostic objects
>>
>> CONFIG_XEN is generated by configure and stored in "config-target.h",
>> which is (obviously) only include for target-specific objects.
>> This is a problem for target-agnostic objects as CONFIG_XEN is never
>> defined and xen_enabled() is always inlined as 'false'.
>>
>> Fix by following the KVM schema, defining CONFIG_XEN_IS_POSSIBLE
>> when we don't know to force the call of the non-inlined function,
>> returning the xen_allowed boolean.
>>
>> Fixes: da278d58a092 ("accel: Move Xen accelerator code under accel/xen/")
>> Reported-by: Paul Durrant <pdurrant@amazon.com>
>> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  include/sysemu/xen.h   | 18 ++++++++++++++----
>>  accel/stubs/xen-stub.c |  2 ++
>>  accel/xen/xen-all.c    |  7 +------
>>  3 files changed, 17 insertions(+), 10 deletions(-)
>>
>> diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
>> index 1ca292715e..2c2c429ea8 100644
>> --- a/include/sysemu/xen.h
>> +++ b/include/sysemu/xen.h
>> @@ -8,9 +8,19 @@
>>  #ifndef SYSEMU_XEN_H
>>  #define SYSEMU_XEN_H
>>
>> -#ifdef CONFIG_XEN
>> +#ifdef NEED_CPU_H
>> +# ifdef CONFIG_XEN
>> +#  define CONFIG_XEN_IS_POSSIBLE
>> +# endif
>> +#else
>> +# define CONFIG_XEN_IS_POSSIBLE
>> +#endif
>>
>> -bool xen_enabled(void);
>> +#ifdef CONFIG_XEN_IS_POSSIBLE
>> +
>> +extern bool xen_allowed;
>> +
>> +#define xen_enabled()           (xen_allowed)
> 
> Can this not move ahead of the #ifdef now (since xen_allowed is present in both xen-stub and xen-all)? I think this is what Peter was saying in his option '(2)'.

I think I respected Peter's option '(2)', following how KVM does, this
is the case with stub,

> 
>   Paul
> 
>>
>>  #ifndef CONFIG_USER_ONLY
>>  void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
>> @@ -18,7 +28,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>>                     struct MemoryRegion *mr, Error **errp);
>>  #endif
>>
>> -#else /* !CONFIG_XEN */
>> +#else /* !CONFIG_XEN_IS_POSSIBLE */
>>
>>  #define xen_enabled() 0

    ^^^ here is the other case,

>>  #ifndef CONFIG_USER_ONLY
>> @@ -33,6 +43,6 @@ static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>>  }
>>  #endif
>>
>> -#endif /* CONFIG_XEN */
>> +#endif /* CONFIG_XEN_IS_POSSIBLE */
>>
>>  #endif
>> diff --git a/accel/stubs/xen-stub.c b/accel/stubs/xen-stub.c
>> index dcca4e678a..8ae658acff 100644
>> --- a/accel/stubs/xen-stub.c
>> +++ b/accel/stubs/xen-stub.c
>> @@ -9,6 +9,8 @@
>>  #include "hw/xen/xen.h"
>>  #include "qapi/qapi-commands-misc.h"
>>
>> +bool xen_allowed;

here is the stub,

>> +
>>  void xenstore_store_pv_console_info(int i, Chardev *chr)
>>  {
>>  }
>> diff --git a/accel/xen/xen-all.c b/accel/xen/xen-all.c
>> index 0c24d4b191..60b971d0a8 100644
>> --- a/accel/xen/xen-all.c
>> +++ b/accel/xen/xen-all.c
>> @@ -32,12 +32,7 @@
>>      do { } while (0)
>>  #endif
>>
>> -static bool xen_allowed;
>> -
>> -bool xen_enabled(void)
>> -{
>> -    return xen_allowed;
>> -}
>> +bool xen_allowed;

here is the real variable.

>>
>>  xc_interface *xen_xc;
>>  xenforeignmemory_handle *xen_fmem;
>> --
>> 2.21.3
> 
>
Paul Durrant Aug. 4, 2020, 8:37 a.m. UTC | #3
> -----Original Message-----
> From: Philippe Mathieu-Daudé <philmd@redhat.com>
> Sent: 04 August 2020 09:35
> To: paul@xen.org; qemu-devel@nongnu.org
> Cc: 'Peter Maydell' <peter.maydell@linaro.org>; 'Anthony Perard' <anthony.perard@citrix.com>; 'Paolo
> Bonzini' <pbonzini@redhat.com>; 'Stefano Stabellini' <sstabellini@kernel.org>; xen-
> devel@lists.xenproject.org; 'Paul Durrant' <pdurrant@amazon.com>
> Subject: Re: [PATCH-for-5.1 v2 1/1] accel/xen: Fix xen_enabled() behavior on target-agnostic objects
> 
> Hi Paul,
> 
> On 8/4/20 9:57 AM, Paul Durrant wrote:
> >> -----Original Message-----
> >> From: Philippe Mathieu-Daudé <philmd@redhat.com>
> >> Sent: 04 August 2020 08:50
> >> To: qemu-devel@nongnu.org
> >> Cc: Peter Maydell <peter.maydell@linaro.org>; Anthony Perard <anthony.perard@citrix.com>; Paolo
> >> Bonzini <pbonzini@redhat.com>; Stefano Stabellini <sstabellini@kernel.org>; xen-
> >> devel@lists.xenproject.org; Paul Durrant <paul@xen.org>; Philippe Mathieu-Daudé
> <philmd@redhat.com>;
> >> Paul Durrant <pdurrant@amazon.com>
> >> Subject: [PATCH-for-5.1 v2 1/1] accel/xen: Fix xen_enabled() behavior on target-agnostic objects
> >>
> >> CONFIG_XEN is generated by configure and stored in "config-target.h",
> >> which is (obviously) only include for target-specific objects.
> >> This is a problem for target-agnostic objects as CONFIG_XEN is never
> >> defined and xen_enabled() is always inlined as 'false'.
> >>
> >> Fix by following the KVM schema, defining CONFIG_XEN_IS_POSSIBLE
> >> when we don't know to force the call of the non-inlined function,
> >> returning the xen_allowed boolean.
> >>
> >> Fixes: da278d58a092 ("accel: Move Xen accelerator code under accel/xen/")
> >> Reported-by: Paul Durrant <pdurrant@amazon.com>
> >> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> >> ---
> >>  include/sysemu/xen.h   | 18 ++++++++++++++----
> >>  accel/stubs/xen-stub.c |  2 ++
> >>  accel/xen/xen-all.c    |  7 +------
> >>  3 files changed, 17 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
> >> index 1ca292715e..2c2c429ea8 100644
> >> --- a/include/sysemu/xen.h
> >> +++ b/include/sysemu/xen.h
> >> @@ -8,9 +8,19 @@
> >>  #ifndef SYSEMU_XEN_H
> >>  #define SYSEMU_XEN_H
> >>
> >> -#ifdef CONFIG_XEN
> >> +#ifdef NEED_CPU_H
> >> +# ifdef CONFIG_XEN
> >> +#  define CONFIG_XEN_IS_POSSIBLE
> >> +# endif
> >> +#else
> >> +# define CONFIG_XEN_IS_POSSIBLE
> >> +#endif
> >>
> >> -bool xen_enabled(void);
> >> +#ifdef CONFIG_XEN_IS_POSSIBLE
> >> +
> >> +extern bool xen_allowed;
> >> +
> >> +#define xen_enabled()           (xen_allowed)
> >
> > Can this not move ahead of the #ifdef now (since xen_allowed is present in both xen-stub and xen-
> all)? I think this is what Peter was saying in his option '(2)'.
> 
> I think I respected Peter's option '(2)', following how KVM does, this
> is the case with stub,

Ok, if it follows the KVM pattern then that's fine.

Reviewed-by: Paul Durrant <paul@xen.org>
Anthony PERARD Aug. 4, 2020, 9:20 a.m. UTC | #4
On Tue, Aug 04, 2020 at 09:49:30AM +0200, Philippe Mathieu-Daudé wrote:
> CONFIG_XEN is generated by configure and stored in "config-target.h",
> which is (obviously) only include for target-specific objects.
> This is a problem for target-agnostic objects as CONFIG_XEN is never
> defined and xen_enabled() is always inlined as 'false'.
> 
> Fix by following the KVM schema, defining CONFIG_XEN_IS_POSSIBLE
> when we don't know to force the call of the non-inlined function,
> returning the xen_allowed boolean.
> 
> Fixes: da278d58a092 ("accel: Move Xen accelerator code under accel/xen/")
> Reported-by: Paul Durrant <pdurrant@amazon.com>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

This time, I've also check that build all targets works...

I'll prepare the pull request right away.

Thank you,
diff mbox series

Patch

diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
index 1ca292715e..2c2c429ea8 100644
--- a/include/sysemu/xen.h
+++ b/include/sysemu/xen.h
@@ -8,9 +8,19 @@ 
 #ifndef SYSEMU_XEN_H
 #define SYSEMU_XEN_H
 
-#ifdef CONFIG_XEN
+#ifdef NEED_CPU_H
+# ifdef CONFIG_XEN
+#  define CONFIG_XEN_IS_POSSIBLE
+# endif
+#else
+# define CONFIG_XEN_IS_POSSIBLE
+#endif
 
-bool xen_enabled(void);
+#ifdef CONFIG_XEN_IS_POSSIBLE
+
+extern bool xen_allowed;
+
+#define xen_enabled()           (xen_allowed)
 
 #ifndef CONFIG_USER_ONLY
 void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
@@ -18,7 +28,7 @@  void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
                    struct MemoryRegion *mr, Error **errp);
 #endif
 
-#else /* !CONFIG_XEN */
+#else /* !CONFIG_XEN_IS_POSSIBLE */
 
 #define xen_enabled() 0
 #ifndef CONFIG_USER_ONLY
@@ -33,6 +43,6 @@  static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
 }
 #endif
 
-#endif /* CONFIG_XEN */
+#endif /* CONFIG_XEN_IS_POSSIBLE */
 
 #endif
diff --git a/accel/stubs/xen-stub.c b/accel/stubs/xen-stub.c
index dcca4e678a..8ae658acff 100644
--- a/accel/stubs/xen-stub.c
+++ b/accel/stubs/xen-stub.c
@@ -9,6 +9,8 @@ 
 #include "hw/xen/xen.h"
 #include "qapi/qapi-commands-misc.h"
 
+bool xen_allowed;
+
 void xenstore_store_pv_console_info(int i, Chardev *chr)
 {
 }
diff --git a/accel/xen/xen-all.c b/accel/xen/xen-all.c
index 0c24d4b191..60b971d0a8 100644
--- a/accel/xen/xen-all.c
+++ b/accel/xen/xen-all.c
@@ -32,12 +32,7 @@ 
     do { } while (0)
 #endif
 
-static bool xen_allowed;
-
-bool xen_enabled(void)
-{
-    return xen_allowed;
-}
+bool xen_allowed;
 
 xc_interface *xen_xc;
 xenforeignmemory_handle *xen_fmem;