Currently, early console output may be lost, e.g. if starting a guest with `virsh start --console` guest, which can make debugging of early failures very difficult (like zipl messages or disabled wait conditions happening early). This is because QEMU may emit serial console output before the libvirt console client starts to consume data from the pts. This can be prevented by starting the guest in paused state, connect to the console and then resume the guest.
Note: There is still a problem in QEMU itself, see QEMU patch series `[PATCH] chardev/char-pty: Avoid losing bytes when the other side just (re-)connected` [1] [1] https://lists.gnu.org/archive/html/qemu-devel/2023-08/msg02725.html Marc Hartmayer (3): virsh: add `console --resume` support Improve `virsh start --console` behavior Improve `virsh create --console` behavior tools/virsh-console.c | 8 ++++++++ tools/virsh-console.h | 1 + tools/virsh-domain.c | 32 ++++++++++++++++++++++++++------ 3 files changed, 35 insertions(+), 6 deletions(-) base-commit: 3fd64fb0e236fc80ffa2cc977c0d471f11fc39bf -- 2.34.1
