| Message ID | 20221111042225.1115931-5-bin.meng@windriver.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | At present there is no Windows support for 9p file system. | expand |
On Fri, Nov 11, 2022 at 12:22:10PM +0800, Bin Meng wrote: > Introduce a new QemuFd_t type to represent a file descriptor for > different platforms. On POSIX platforms, this is a file descriptor > On Windows, this is a file handle. Can we not use _open_osfhandle() to obtain a C runtime file descriptor from the Windows HANDLE. We do this in QEMU's socket code, so we don't have to work wit different types and APIs on Windows, and I think that's much nicer in general. > > Changes in v2: > - Change to introduce QemuFd_t in osdep.h > > include/qemu/osdep.h | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > index b9c4307779..45fc8bb5d9 100644 > --- a/include/qemu/osdep.h > +++ b/include/qemu/osdep.h > @@ -705,6 +705,32 @@ static inline int platform_does_not_support_system(const char *command) > } > #endif /* !HAVE_SYSTEM_FUNCTION */ > > +/* > + * QEMU file descriptor type > + * > + * On POSIX platforms, this is a file descriptor (int). > + * On Windows, this is a file handle (HANDLE). > + */ > +#ifndef _WIN32 > +typedef int QemuFd_t; > +#define QEMU_FD_INVALID -1 > +#else > +typedef HANDLE QemuFd_t; > +#define QEMU_FD_INVALID INVALID_HANDLE_VALUE > +#endif > + > +/** > + * qemu_fd_invalid - determine if a given QEMU file descriptor is invalid > + * > + * @fd: the value of a QEMU file descriptor > + * > + * Returns true if a given QEMU file descriptor is invalid, otherwise false. > + */ > +static inline bool qemu_fd_invalid(QemuFd_t fd) > +{ > + return (fd == QEMU_FD_INVALID); > +} > + > #ifdef __cplusplus > } > #endif > -- > 2.25.1 > With regards, Daniel
Hi Daniel, On Fri, Nov 11, 2022 at 5:08 PM Daniel P. Berrangé <berrange@redhat.com> wrote: > > On Fri, Nov 11, 2022 at 12:22:10PM +0800, Bin Meng wrote: > > Introduce a new QemuFd_t type to represent a file descriptor for > > different platforms. On POSIX platforms, this is a file descriptor > > On Windows, this is a file handle. > > Can we not use _open_osfhandle() to obtain a C runtime > file descriptor from the Windows HANDLE. We do this in > QEMU's socket code, so we don't have to work wit different > types and APIs on Windows, and I think that's much nicer > in general. > I am sorry I don't understand your suggestion. I checked qemu-sockets.c and did not see how sockets connect to this change. This change is required to make 9pfs Windows support much easier. Regards, Bin
On Fri, Nov 11, 2022 at 05:23:58PM +0800, Bin Meng wrote: > Hi Daniel, > > On Fri, Nov 11, 2022 at 5:08 PM Daniel P. Berrangé <berrange@redhat.com> wrote: > > > > On Fri, Nov 11, 2022 at 12:22:10PM +0800, Bin Meng wrote: > > > Introduce a new QemuFd_t type to represent a file descriptor for > > > different platforms. On POSIX platforms, this is a file descriptor > > > On Windows, this is a file handle. > > > > Can we not use _open_osfhandle() to obtain a C runtime > > file descriptor from the Windows HANDLE. We do this in > > QEMU's socket code, so we don't have to work wit different > > types and APIs on Windows, and I think that's much nicer > > in general. > > > > I am sorry I don't understand your suggestion. I checked > qemu-sockets.c and did not see how sockets connect to this change. > > This change is required to make 9pfs Windows support much easier. I'm just using it as an example to show that we can continue to use a plain 'int fd' everywhere, and not invent a QemuFd_t type abstraction With regards, Daniel
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index b9c4307779..45fc8bb5d9 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -705,6 +705,32 @@ static inline int platform_does_not_support_system(const char *command) } #endif /* !HAVE_SYSTEM_FUNCTION */ +/* + * QEMU file descriptor type + * + * On POSIX platforms, this is a file descriptor (int). + * On Windows, this is a file handle (HANDLE). + */ +#ifndef _WIN32 +typedef int QemuFd_t; +#define QEMU_FD_INVALID -1 +#else +typedef HANDLE QemuFd_t; +#define QEMU_FD_INVALID INVALID_HANDLE_VALUE +#endif + +/** + * qemu_fd_invalid - determine if a given QEMU file descriptor is invalid + * + * @fd: the value of a QEMU file descriptor + * + * Returns true if a given QEMU file descriptor is invalid, otherwise false. + */ +static inline bool qemu_fd_invalid(QemuFd_t fd) +{ + return (fd == QEMU_FD_INVALID); +} + #ifdef __cplusplus } #endif
Introduce a new QemuFd_t type to represent a file descriptor for different platforms. On POSIX platforms, this is a file descriptor On Windows, this is a file handle. Signed-off-by: Bin Meng <bin.meng@windriver.com> --- Changes in v2: - Change to introduce QemuFd_t in osdep.h include/qemu/osdep.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)