Re: [PATCH 2/5] util/oslib-win32: Add a helper to get the Windows version

[Bin Meng]

On Wed, Jul 27, 2022 at 4:50 PM Yan Vugenfirer <yvugenfi@redhat.com> wrote:
>
> On Wed, Jul 27, 2022 at 10:43 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > From: Bin Meng <bin.meng@windriver.com>
> >
> > This adds a helper to get the Windows version via the RtlGetVersion
> > call, for QEMU codes to determine the Windows version at run-time.
> >
> > Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
> > Signed-off-by: Bin Meng <bin.meng@windriver.com>
> > ---
> >
> >  include/sysemu/os-win32.h |  2 ++
> >  util/oslib-win32.c        | 15 +++++++++++++++
> >  2 files changed, 17 insertions(+)
> >
> > diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
> > index edc3b38a57..1e324026a4 100644
> > --- a/include/sysemu/os-win32.h
> > +++ b/include/sysemu/os-win32.h
> > @@ -204,6 +204,8 @@ ssize_t qemu_recv_wrap(int sockfd, void *buf, size_t 
> > len, int flags);
> >  ssize_t qemu_recvfrom_wrap(int sockfd, void *buf, size_t len, int flags,
> >                             struct sockaddr *addr, socklen_t *addrlen);
> >
> > +void os_get_win_version(RTL_OSVERSIONINFOEXW *info);
> > +
> >  #ifdef __cplusplus
> >  }
> >  #endif
> > diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> > index 5723d3eb4c..6d2387b9ff 100644
> > --- a/util/oslib-win32.c
> > +++ b/util/oslib-win32.c
> > @@ -547,3 +547,18 @@ int qemu_msync(void *addr, size_t length, int fd)
> >       */
> >      return qemu_fdatasync(fd);
> >  }
> > +
> > +void os_get_win_version(RTL_OSVERSIONINFOEXW *info)
> > +{
> > +    typedef LONG (WINAPI *rtl_get_version_t)(PRTL_OSVERSIONINFOEXW);
> > +
> > +    /* RtlGetVersion is available starting with Windows 2000 */
> > +    HMODULE module = GetModuleHandle("ntdll");
> > +    PVOID fun = GetProcAddress(module, "RtlGetVersion");
> > +    rtl_get_version_t rtl_get_version = (rtl_get_version_t)fun;
> > +
> > +    info->dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
> > +    rtl_get_version(info);
> The original function, when it was present in qemu-ga, tested that
> getting the function address succeeded.
> I think this test should be kept.
> See below:
> -    PVOID fun = GetProcAddress(module, "RtlGetVersion");
> -    if (fun == NULL) {
> -        error_setg(errp, QERR_QGA_COMMAND_FAILED,
> -            "Failed to get address of RtlGetVersion");
> -        return;
> -    }
>

Please see the comment:

/* RtlGetVersion is available starting with Windows 2000 */

I don't think we need that check.

Regards,
Bin