[−][src]Function vmm_sys_util::ioctl::ioctl_with_val
pub unsafe fn ioctl_with_val<F: AsRawFd>(
fd: &F,
req: c_ulong,
arg: c_ulong
) -> c_int
Run an ioctl
with a single value argument.
Arguments
fd
: an open file descriptor corresponding to the device on which to call the ioctl.req
: a device-dependent request code.arg
: a single value passed to ioctl.
Safety
The caller should ensure to pass a valid file descriptor and have the return value checked.
Examples
#[macro_use] extern crate vmm_sys_util; use vmm_sys_util::ioctl::ioctl_with_val; const KVMIO: c_uint = 0xAE; const KVM_CAP_USER_MEMORY: u32 = 3; ioctl_io_nr!(KVM_CHECK_EXTENSION, KVMIO, 0x03); let open_flags = O_RDWR | O_CLOEXEC; let kvm_fd = unsafe { open("/dev/kvm\0".as_ptr() as *const c_char, open_flags) }; let ret = unsafe { ioctl_with_val( &File::from_raw_fd(kvm_fd), KVM_CHECK_EXTENSION(), KVM_CAP_USER_MEMORY as c_ulong, ) }; assert!(ret > 0);