On Wed, 06.07.11 10:22, Daniel P. Berrange (berrange@xxxxxxxxxx) wrote: > > So, I am a bit confused now after reading this: > > > > http://fedoraproject.org/wiki/Features/VirtioSerial > > > > How does /dev/hvcxxx relate to these virtio ports? > > > > hvc ports are tagged "systemd" anyway in udev, so if this is the same > > thing, why do we have to tag the virtio ports too? > > > > Can you explain how hvc and virtio relate to each other and under which > > kernel device names they show up in udev and how they correspond? > > In QEMU, there is one PCI device "virtio-serial-pci". In QEMU's view this > device is a bus to which we then attach zero or more 'virtconsole' or > 'virtserialport' devices. > > The 'virtconsole' device is a paravirt text console, which appears as > /dev/hvcNNN in the guest. These are intended for interactive login and > would be expected to run a mingetty/agetty process. Hmm, but Unix does not really distuingish between serial ports and ttys. So what precisely is the difference in behaviour when I have opened a /dev/hvcXX and a /dev/vportXXX? What happens if start a getty on /dev/vportXXX? And why couldn't I use /dev/hvcXXX for fast data transfer, too? Or is the only difference on the host side? i.e. the destinction between access via pty and access via sockets? Lennart -- Lennart Poettering - Red Hat, Inc. -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
