DMA-BUF: "Guest has not initialized the display (yet)."

[tthbaltazar]

HI! I'm on an arch linux host and trying to run win10 in a VM.

I have two GPUs: the one in my CPU(i5-6400, HD 530) and an nvidia 1060 3gb. My monitors are connected to the nvidia gpu.

I've managed to setup GVT-g, but I can't use DMA-BUF to view the screen.

I've installed the drivers and I can set a resolution. It even boots with only the GVT-g GPU and I had keyboard input: I could shut it down by using win10 keyboard shortcuts. But there is no image. The QEMU window says "Guest has not initialized the display (yet)."

I've tried using spice but that too only shows the emulated GPU and it has an even worse performance.

Once in a while windows crashes on boot, and sometimes I get "bad address" errors.

qemu-system-x86_64: vfio_region_write(77fe23a8-d315-47a0-9078-9f441f8a441c:region0+0x2080, 0x0,4) failed: Bad address
qemu-system-x86_64: vfio_region_write(77fe23a8-d315-47a0-9078-9f441f8a441c:region0+0x12080, 0x0,4) failed: Bad address
qemu-system-x86_64: vfio_region_write(77fe23a8-d315-47a0-9078-9f441f8a441c:region0+0x22080, 0x0,4) failed: Bad address
qemu-system-x86_64: vfio_region_write(77fe23a8-d315-47a0-9078-9f441f8a441c:region0+0x1a080, 0x0,4) failed: Bad address

(77fe23a8-d315-47a0-9078-9f441f8a441c being the UUID I've used for GVT-g)

Other strange issue I ran into is that with GTK if I use gl=on not even the emulated GPU's image is visible.

QEMU version: 5.2.0 (arch official build)
uname: Linux ARCHPC 5.9.14-arch1-1 #1 SMP PREEMPT Sat, 12 Dec 2020 14:37:12 +0000 x86_64 GNU/Linux

Launch script:

#!/bin/sh

GVT_GUID=77fe23a8-d315-47a0-9078-9f441f8a441c

qemu-system-x86_64 \
 -enable-kvm \
 -cpu host -smp 4 -m 4G \
 -vga none \
 -display sdl,gl=on \
 -device vfio-pci,sysfsdev=/sys/bus/mdev/devices/$GVT_GUID,display=on,x-igd-opregion=on \
 testing.img

[sloonz]

I have basically the same issue.

/usr/bin/qemu-system-x86_64 \                                            
    -m 2048 -smp 2 -M pc \                                                                                                                                                   
    -name local-display-vm \                                                                                                                                                                                          
    -hda base.img \                                                                                                                                                                                                       
    -enable-kvm \                                                                                                                                                                                                     
    -net none -nic none \                                                                                                                                                                                             
    -display gtk,gl=on \                                                                                                                                                                                                    
    -k en-us \                                                                                                                                                                                                        
    -machine kernel_irqchip=on \                                                                                                                                                                                      
    -global PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 \                                                                                                                                                     
    -cpu host -usb -usbdevice tablet \                                                                                                                                                                                
    -vga none \                                                                                                                                                                                         
    -device vfio-pci,sysfsdev=/sys/bus/pci/devices/0000:00:02.0/$uuid,display=on,x-igd-opregion=on,ramfb=on

i7-7700 / QEMU 5.2.0 / Linux Host 5.11.7 / Window Guest 10 (20H2) / Guest drivers: tested both 26.20.100.7985 and 27.20.100.9316

In Devices Management (in the guest) the driver is correctly loaded. dxdiag indicates two displays, the first one assigned to basic VGA adapter, the second to Intel HD Graphics 630. However :

• QEMU never switch to the second one (as I understand, it should do so as soon as the graphics driver initialize it)
• Setting ramfb to off, the message "Guest has not initialized the display (yet)." never disappears
• Showing only 2nd screen on Display Settings gives a black screen

[lurenJBD]

I have basically the same issue.

/usr/bin/qemu-system-x86_64 \                                            
    -m 2048 -smp 2 -M pc \                                                                                                                                                   
    -name local-display-vm \                                                                                                                                                                                          
    -hda base.img \                                                                                                                                                                                                       
    -enable-kvm \                                                                                                                                                                                                     
    -net none -nic none \                                                                                                                                                                                             
    -display gtk,gl=on \                                                                                                                                                                                                    
    -k en-us \                                                                                                                                                                                                        
    -machine kernel_irqchip=on \                                                                                                                                                                                      
    -global PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 \                                                                                                                                                     
    -cpu host -usb -usbdevice tablet \                                                                                                                                                                                
    -vga none \                                                                                                                                                                                         
    -device vfio-pci,sysfsdev=/sys/bus/pci/devices/0000:00:02.0/$uuid,display=on,x-igd-opregion=on,ramfb=on

i7-7700 / QEMU 5.2.0 / Linux Host 5.11.7 / Window Guest 10 (20H2) / Guest drivers: tested both 26.20.100.7985 and 27.20.100.9316

In Devices Management (in the guest) the driver is correctly loaded. dxdiag indicates two displays, the first one assigned to basic VGA adapter, the second to Intel HD Graphics 630. However :

• QEMU never switch to the second one (as I understand, it should do so as soon as the graphics driver initialize it)
• Setting ramfb to off, the message "Guest has not initialized the display (yet)." never disappears
• Showing only 2nd screen on Display Settings gives a black screen

Hi, I'm having a similar problem, any progress? #233 (comment)