Re: [PATCH v3 13/22] target/i386/sev: Remove stubs by using code elision

[Brijesh Singh]

On 10/6/21 11:55 AM, Philippe Mathieu-Daudé wrote:
> On 10/4/21 10:19, Paolo Bonzini wrote:
>> On 02/10/21 14:53, Philippe Mathieu-Daudé wrote:
>>> Only declare sev_enabled() and sev_es_enabled() when CONFIG_SEV is
>>> set, to allow the compiler to elide unused code. Remove unnecessary
>>> stubs.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> ---
>>>   include/sysemu/sev.h    | 14 +++++++++++++-
>>>   target/i386/sev_i386.h  |  3 ---
>>>   target/i386/cpu.c       | 16 +++++++++-------
>>>   target/i386/sev-stub.c  | 36 ------------------------------------
>>>   target/i386/meson.build |  2 +-
>>>   5 files changed, 23 insertions(+), 48 deletions(-)
>>>   delete mode 100644 target/i386/sev-stub.c
>>>
>>> diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
>>> index a329ed75c1c..f5c625bb3b3 100644
>>> --- a/include/sysemu/sev.h
>>> +++ b/include/sysemu/sev.h
>>> @@ -14,9 +14,21 @@
>>>   #ifndef QEMU_SEV_H
>>>   #define QEMU_SEV_H
>>>   -#include "sysemu/kvm.h"
>>> +#ifndef CONFIG_USER_ONLY
>>> +#include CONFIG_DEVICES /* CONFIG_SEV */
>>> +#endif
>>>   +#ifdef CONFIG_SEV
>>>   bool sev_enabled(void);
>>> +bool sev_es_enabled(void);
>>> +#else
>>> +#define sev_enabled() 0
>>> +#define sev_es_enabled() 0
>>> +#endif
>> This means that sev.h can only be included from target-specific files.
>>
>> An alternative could be:
>>
>> #ifdef NEED_CPU_H
>> # include CONFIG_DEVICES
> <command-line>: fatal error: x86_64-linux-user-config-devices.h: No such
> file or directory
>
>> #endif
>>
>> #if defined NEED_CPU_H && !defined CONFIG_SEV
>> # define sev_enabled() 0
>> # define sev_es_enabled() 0
>> #else
>> bool sev_enabled(void);
>> bool sev_es_enabled(void);
>> #endif
>>
>> ... but in fact sysemu/sev.h _is_ only used from x86-specific files. So
>> should it be moved to include/hw/i386, and even merged with
>> target/i386/sev_i386.h?  Do we need two files?
> No clue, I don't think we need. Brijesh?


Sorry for the late reply, we do not need two files and it can be easily
merged.

thanks