Re: [libvirt] [Qemu-devel] [PATCH v4 0/7] file descriptor passing using pass-fd

On 07/02/2012 04:02 PM, Corey Bryant wrote: > Here's another option that Kevin and I discussed today on IRC. I've > modified a few minor details since the discussion. And Kevin please > correct me if anything is wrong. > > Proposal Four: Pass a set of fds via 'pass-fds'. The group of fds > should all refer to the same file, but may have different access flags > (ie. O_RDWR, O_RDONLY). qemu_open can then dup the fd that has the > matching access mode flags. But this means that libvirt has to open a file O_RDWR up front for any file that it _might_ need qemu to reopen later, and that qemu is now hanging on to 2 fds per fdset instead of 1 fd for the life of any client of the fdset. I see no reason why libvirt can't pass in an O_RDWR fd when qemu only needs to use an O_RDONLY fd;