Steve Sistare <steven.sist...@oracle.com> writes: > Add the helper function cpr_get_fd_param, to use when preserving > a file descriptor that is opened externally and passed to QEMU. > cpr_get_fd_param returns a descriptor number either from a QEMU > command-line parameter, from a getfd command, or from CPR state. > > When a descriptor is passed to new QEMU via SCM_RIGHTS, its number > changes. Hence, during CPR, the command-line parameter is ignored > in new QEMU, and over-ridden by the value found in CPR state. > > Similarly, if the descriptor was originally specified by a getfd > command in old QEMU, the fd number is not known outside of QEMU, > and it changes when sent to new QEMU via SCM_RIGHTS. Hence the > user cannot send getfd to new QEMU, but when the user sends a > hotplug command that references the fd, cpr_get_fd_param finds > its value in CPR state. > > Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
Reviewed-by: Fabiano Rosas <faro...@suse.de>
