1*f616b10bSSasha LevinGeneral 2*f616b10bSSasha Levin-------- 3*f616b10bSSasha Levin 4*f616b10bSSasha Levinvirtio-console as the name implies is a console over virtio transport. Here is 5*f616b10bSSasha Levina simple head to head comparison of the virtio-console vs regular 8250 console: 6*f616b10bSSasha Levin 7*f616b10bSSasha Levin8250 serial console: 8*f616b10bSSasha Levin 9*f616b10bSSasha Levin - Requires CONFIG_SERIAL_8250=y and CONFIG_SERIAL_8250_CONSOLE=y kernel configs, 10*f616b10bSSasha Levinwhich are enabled almost everywhere. 11*f616b10bSSasha Levin - Doesn't require guest-side changes. 12*f616b10bSSasha Levin - Compatible with older guests. 13*f616b10bSSasha Levin 14*f616b10bSSasha Levinvirtio-console: 15*f616b10bSSasha Levin 16*f616b10bSSasha Levin - Requires CONFIG_VIRTIO_CONSOLE=y (along with all other virtio dependencies), 17*f616b10bSSasha Levinwhich got enabled only in recent kernels (but not all of them). 18*f616b10bSSasha Levin - Much faster. 19*f616b10bSSasha Levin - Consumes less processing resources. 20*f616b10bSSasha Levin - Requires guest-side changes. 21*f616b10bSSasha Levin 22*f616b10bSSasha LevinEnabling virtio-console 23*f616b10bSSasha Levin------------------------ 24*f616b10bSSasha Levin 25*f616b10bSSasha LevinFirst, make sure guest kernel is built with CONFIG_VIRTIO_CONSOLE=y. Once this 26*f616b10bSSasha Levinis done, the following has to be done inside guest image: 27*f616b10bSSasha Levin 28*f616b10bSSasha Levin - Add the following line to /etc/inittab: 29*f616b10bSSasha Levin 'hvc0:2345:respawn:/sbin/agetty -L 9600 hvc0' 30*f616b10bSSasha Levin - Add 'hvc0' to /etc/securetty (so you could actually log on) 31*f616b10bSSasha Levin - Start the guest with '--console virtio' 32*f616b10bSSasha Levin 33*f616b10bSSasha LevinCommon errors 34*f616b10bSSasha Levin-------------- 35*f616b10bSSasha Levin 36*f616b10bSSasha LevinQ: I don't see anything on the screen! 37*f616b10bSSasha LevinA: Make sure CONFIG_VIRTIO_CONSOLE=y is enabled in the *guest* kernel, also 38*f616b10bSSasha Levinmake sure you've updated /etc/inittab 39*f616b10bSSasha Levin 40*f616b10bSSasha LevinQ: It won't accept my username/password, but I enter them correctly! 41*f616b10bSSasha LevinA: You didn't add 'hvc0' to /etc/securetty 42