Hi Gerd,

Here is what I got:

[ 813.137939] [drm:drm_pci_init]

[ 813.142780] [drm:drm_get_pci_dev]

[ 813.156986] [drm:drm_minor_register]

[ 813.212679] [drm:drm_minor_register] new minor registered 64

[ 813.213341] [drm:drm_minor_register]

[ 813.215081] [drm:drm_minor_register]

[ 813.235736] [drm:drm_minor_register] new minor registered 0

[ 813.252701] [drm] Found bochs VGA, ID 0xb0c0.

[ 813.254993] [drm] Framebuffer size 8192 kB @ 0xfe000000, ioports @ 0x1ce.

[ 813.271384] [TTM] Zone kernel: Available graphics memory: 513150 kiB

[ 813.272036] [TTM] Initializing pool allocator

[ 813.279538] [TTM] Initializing DMA pool allocator

[ 813.299800] [drm:drm_sysfs_connector_add] adding "Virtual-1" to sysfs

[ 813.303164] [drm:drm_sysfs_hotplug_event] generating hotplug event

[ 813.313079] [drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on minor 0

If I remove the bochs-drm.ko from its place, then boot the virtual machine, after it runs,

copy the bochs-drm.ko to its original place, depmod the module, and modprobe

bochs-drm, it give the messages above. Seems like the bochs driver works, but

if I reboot with the bochs-drm.ko, it goes to dark, and the messages related to bochs

is same as above.

I guess the problem is because that I take no care of bochs_hw_setbase after remove

the bochs_crtc_mode_set_base, but I am not sure.

I will be appreciate if you can review the patch a bit and tell me where the problem

might be, and I will dig more into that.

I really can't get any clue.

If my question is stupid, forgive me, I will try to catch up :)

Best Regards,

Zhao

On Wed, Jun 10, 2015 at 8:20 PM, Gerd Hoffmann <kraxel@redhat.com> wrote:

On Mi, 2015-06-10 at 19:39 +0800, John Hunter wrote:
> Hi Gerd,
> I have tried what you told me.
> 1. Turn off fbdev support:
> static bool enable_fbdev = false;

Good.

> 2. configure a serial console:
> - add something like "console=ttyS0, 9600n8" to the grub menuentry

Good.

You can use 115200 as line speed to speedup the console a bit.

> - add a start parameter to qemu when start the virtual machine
> "-serial pty"

'-serial stdio' might be more convenient.

> saned disabled; edit /etc/default/saned
> [ ok ] Starting network connection manager: NetworkManager.
> [ ok ] Starting Common Unix Printing System: cupsd.
>
>
> The serial console messages also stop here, no other output.

Which guest is this? On modern linux distros (anything systemd-based)
you should automatically get a login prompt on the serial line in case
it is configured as console. Older systems need manual configuration
for that. Could also be the system simply hangs here.

Try adding "ignore_loglevel" and "drm.debug=0x07" to the kernel command
line.

HTH,
Gerd

Best regards

Junwang Zhao

Microprocessor Research and Develop Center

Department of Computer Science &Technology

Peking University

Beijing, 100871, PRC