Re: [PATCH V2] WHPX: refactor load library

[Paolo Bonzini <pbonzini@redhat.com>]

On 13/11/19 19:54, Sunil Muthuswamy wrote:
> This refactors the load library of WHV libraries to make it more
> modular. It makes a helper routine that can be called on demand.
> This allows future expansion of load library/functions to support
> functionality that is dependent on some feature being available.
> 
> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
> ---
> Changes since v1:
> - Fixed typo of load_whp_dispatch_fns
> - Fixed free of the right handle
> 
>  target/i386/whp-dispatch.h |  4 +++
>  target/i386/whpx-all.c     | 85 +++++++++++++++++++++++++++++++---------------
>  2 files changed, 62 insertions(+), 27 deletions(-)
> 
> diff --git a/target/i386/whp-dispatch.h b/target/i386/whp-dispatch.h
> index 23791fbb47..87d049ceab 100644
> --- a/target/i386/whp-dispatch.h
> +++ b/target/i386/whp-dispatch.h
> @@ -50,5 +50,9 @@ extern struct WHPDispatch whp_dispatch;
>  
>  bool init_whp_dispatch(void);
>  
> +typedef enum WHPFunctionList {
> +    WINHV_PLATFORM_FNS_DEFAULT,
> +    WINHV_EMULATION_FNS_DEFAULT,
> +} WHPFunctionList;
>  
>  #endif /* WHP_DISPATCH_H */
> diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
> index ed95105eae..f3c61fa5d8 100644
> --- a/target/i386/whpx-all.c
> +++ b/target/i386/whpx-all.c
> @@ -1356,6 +1356,58 @@ static void whpx_handle_interrupt(CPUState *cpu, int mask)
>      }
>  }
>  
> +/*
> + * Load the functions from the given library, using the given handle. If a
> + * handle is provided, it is used, otherwise the library is opened. The
> + * handle will be updated on return with the opened one.
> + */
> +static bool load_whp_dispatch_fns(HMODULE *handle,
> +    WHPFunctionList function_list)
> +{
> +    HMODULE hLib = *handle;
> +
> +    #define WINHV_PLATFORM_DLL "WinHvPlatform.dll"
> +    #define WINHV_EMULATION_DLL "WinHvEmulation.dll"
> +    #define WHP_LOAD_FIELD(return_type, function_name, signature) \
> +        whp_dispatch.function_name = \
> +            (function_name ## _t)GetProcAddress(hLib, #function_name); \
> +        if (!whp_dispatch.function_name) { \
> +            error_report("Could not load function %s", #function_name); \
> +            goto error; \
> +        } \
> +
> +    #define WHP_LOAD_LIB(lib_name, handle_lib) \
> +    if (!handle_lib) { \
> +        handle_lib = LoadLibrary(lib_name); \
> +        if (!handle_lib) { \
> +            error_report("Could not load library %s.", lib_name); \
> +            goto error; \
> +        } \
> +    } \
> +
> +    switch (function_list) {
> +    case WINHV_PLATFORM_FNS_DEFAULT:
> +        WHP_LOAD_LIB(WINHV_PLATFORM_DLL, hLib)
> +        LIST_WINHVPLATFORM_FUNCTIONS(WHP_LOAD_FIELD)
> +        break;
> +
> +    case WINHV_EMULATION_FNS_DEFAULT:
> +        WHP_LOAD_LIB(WINHV_EMULATION_DLL, hLib)
> +        LIST_WINHVEMULATION_FUNCTIONS(WHP_LOAD_FIELD)
> +        break;
> +    }
> +
> +    *handle = hLib;
> +    return true;
> +
> +error:
> +    if (hLib) {
> +        FreeLibrary(hLib);
> +    }
> +
> +    return false;
> +}
> +
>  /*
>   * Partition support
>   */
> @@ -1491,51 +1543,30 @@ static void whpx_type_init(void)
>  
>  bool init_whp_dispatch(void)
>  {
> -    const char *lib_name;
> -    HMODULE hLib;
> -
>      if (whp_dispatch_initialized) {
>          return true;
>      }
>  
> -    #define WHP_LOAD_FIELD(return_type, function_name, signature) \
> -        whp_dispatch.function_name = \
> -            (function_name ## _t)GetProcAddress(hLib, #function_name); \
> -        if (!whp_dispatch.function_name) { \
> -            error_report("Could not load function %s from library %s.", \
> -                         #function_name, lib_name); \
> -            goto error; \
> -        } \
> -
> -    lib_name = "WinHvPlatform.dll";
> -    hWinHvPlatform = LoadLibrary(lib_name);
> -    if (!hWinHvPlatform) {
> -        error_report("Could not load library %s.", lib_name);
> +    if (!load_whp_dispatch_fns(&hWinHvPlatform, WINHV_PLATFORM_FNS_DEFAULT)) {
>          goto error;
>      }
> -    hLib = hWinHvPlatform;
> -    LIST_WINHVPLATFORM_FUNCTIONS(WHP_LOAD_FIELD)
>  
> -    lib_name = "WinHvEmulation.dll";
> -    hWinHvEmulation = LoadLibrary(lib_name);
> -    if (!hWinHvEmulation) {
> -        error_report("Could not load library %s.", lib_name);
> +    if (!load_whp_dispatch_fns(&hWinHvEmulation, WINHV_EMULATION_FNS_DEFAULT)) {
>          goto error;
>      }
> -    hLib = hWinHvEmulation;
> -    LIST_WINHVEMULATION_FUNCTIONS(WHP_LOAD_FIELD)
>  
>      whp_dispatch_initialized = true;
> -    return true;
> -
> -    error:
>  
> +    return true;
> +error:
>      if (hWinHvPlatform) {
>          FreeLibrary(hWinHvPlatform);
>      }
> +
>      if (hWinHvEmulation) {
>          FreeLibrary(hWinHvEmulation);
>      }
> +
>      return false;
>  }
>  
> 

Queued, thanks.

Paolo