Description of problem: A regression was introduced in QEMU 6.0.0 where socket file descriptor passing on the command-line no longer works. Rich Jones posted an example along these lines: $ qemu-storage-daemon --nbd-server addr.type=fd,addr.str=4 qemu-storage-daemon: --nbd-server addr.type=fd,addr.str=4: socket_get_fd: too many connections: Invalid argument This regression broke the libnbd test suite (see QEMU GitLab Issue link). Version-Release number of selected component (if applicable): How reproducible: 100% Steps to Reproduce: 1. $ qemu-storage-daemon --nbd-server addr.type=fd,addr.str=4 Actual results: qemu-storage-daemon: --nbd-server addr.type=fd,addr.str=4: socket_get_fd: too many connections: Invalid argument Expected results: qemu-storage-daemon: --nbd-server addr.type=fd,addr.str=4: File descriptor '4' is not a socket Note that this is still an error message because we did not actually provide a file descriptor to the qemu-storage-daemon process. But this new error shows that QEMU has identified fd 4 and is trying to access it as expected. Additional info:
Reproduce the bug on rhel8.5: Version: qemu-kvm-6.0.0-17.module+el8.5.0+11173+c9fce0bb.x86_64 kernel-4.18.0-310.el8.x86_64 Steps and results: # qemu-storage-daemon --nbd-server addr.type=fd,addr.str=4 qemu-storage-daemon: --nbd-server addr.type=fd,addr.str=4: socket_get_fd: too many connections: Invalid argument
Verified this issue, report error as expected. Version: qemu-kvm-6.0.0-19.module+el8.5.0+11385+6e7d542e.x86_64 kernel-4.18.0-310.el8.x86_64 Steps: # qemu-storage-daemon --nbd-server addr.type=fd,addr.str=4 qemu-storage-daemon: --nbd-server addr.type=fd,addr.str=4: File descriptor '4' is not a socket The result is as expected, set status to verified.
Set Verified:Tested,SanityOnly as gating/tier1 test pass.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (virt:av bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2021:4684