Hi Vincent, Vincent Caron <vincent@zerodeux.net> (2018-07-06): > Package: debian-installer-9-netboot-amd64 > Severity: wishlist > Tags: d-i > > Dear Maintainer, > > while automating Debian image creations thru netinst + KVM, I stumbled > upon a limitation from the emulated UARTs (if one sends back from the > guest to the host large logs, it might overrun the UART buffer which > complains with kernel messages about overused IRQ). > > While turning to paravirtualized serial, I realized that the > char/virtio_console kernel module is missing in the netinst's initrd, > and this driver is required very early. Obviously I still use the UART > emulation for kernel messages since it's the only _very early_ output > medium, thus emulated UART and paravirtualized serials should be used > together. You mention netinst a few times, but you seem to be talking about netboot really. netinst is an ISO image with a bunch of packages, enough to configure everything needed to pull the rest of the system from a network mirror; netboot is kernel+initrd for PXE boots and similar minimalistic approaches. > If this module makes it to netinst's initrd, one would use those kvm > args: > > -chardev file,path=virtiocon0.log,id=virtiocon0 > -device virtio-serial > -device virtconsole,chardev=virtiocon0 > > ... and in the guest a /dev/hvc0 would appear. Anything the guest would > write to /dev/hv0 would en up in the host's vitriocon0.log file. So it seems we're talking about kernel/drivers/char/virtio_console.ko that could be added to either the serial-modules udeb or the virtio-modules one. Kernel maintainers, what do you think? This might be worth backporting to stretch too. I can send patches when you've selected the udeb we should be adding this module to. Cheers, -- Cyril Brulebois (kibi@debian.org) <https://debamax.com/> D-I release manager -- Release team member -- Freelance Consultant
Attachment:
signature.asc
Description: PGP signature