Is there a way to get GRUB2 and the kernel to run a "serial" console under KVM?
I'm running a Fedora 20 desktop, with libvirt-managed VMs. When I run a CentOS 6 VM, I can set both the boot loader and kernel up to use ttyS0 and get a console compatible with "virsh console".
When I try the same with a CentOS 7 VM, it doesn't work. If I set it to ttyS0, I just don't get anything. I read that I should use hvc0 instead (no idea how to set the boot loader to use that); when I set that on the kernel command line, the kernel crashes during boot with:
kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle kernel paging request at ffffffff81a4cfec IP: [<ffffffff81a4cfec>] vty_init+0x174/0x174 PGD 18d3067 PUD 18d4063 PMD 3d9e1063 PTE 8000000001a4c163
If I don't do either, I can add a getty on hvc0 with "systemctl enable serial-getty@hvc0.service", but that doesn't get me the boot loader or kernel messages.