[Qemu-devel] Passing fds through a qemu char device

[Cam Macdonell <cam@cs.ualberta.ca>]

Hi,

I'm trying to pass eventfds between qemu processes and I'm trying to use 
a qemu char device to do this.  AFAICT with a qemu_chr_device the 
polling handler only has support to call read()/write(), not 
send/recvmsg() which are necessary to send and receive fds with 
SCM_RIGHTS through the socket.  Is this true or is there support in Qemu 
for recvmsg() that I'm not seeing?

If not, some options I can see are to add qemu support for 
qemu_chr_recvmsg() to call on the char device.  Or I can simply manage 
the socket outside of qemu_chr_device, but the polling is helpful for 
notifications and I'd prefer to leverage qemu's existing support for that.

Thanks,
Cam