[Qemu-devel] Re: [PATCH] Migration via unix sockets.

[Paolo Bonzini <bonzini@gnu.org>]

 > That means that you have to first arrange for it not to be closed on
 > exec, and it also means that qemu is now depending on the external
 > program to correctly set up the incoming socket so that qemu can just
 > do the accept() on it.

At this point, I wonder if it isn't better to move the accept to the 
external program, so that it could even use a pipe.  The accept can be 
replaced by

struct pollfd pfd;
pfd.fd = fd;
pfd.events = POLLIN;
poll (&pfd, 1, INFTIM);
if (pfd.revents & (POLLERR | POLLHUP | POLLNVAL))
   handle_error ();

or the equivalent using select.

Paolo