Re: [vfio-users] vga passthrough works but no grub screen for linux guest
On 1/7/19 8:11 am, Christoph Willing wrote: > On 30/6/19 11:07 pm, Bronek Kozicki wrote: >> On Sun, 30 Jun 2019, at 1:41 PM, Christoph Willing wrote: >>> I have vga passthrough working with a linux guest running in qemu-3.1.0 >>> on a host with two Nvidia Quadro K600 cards and the nvidia binary driver >>> 430.26 installed. A dedicated keyboard & mouse is also passed through >>> successfully so, in general, I'm pretty happy with the setup but ... >>> >>> when I use OVMF and run the guest without passthrough (just a regular >>> qemu vm running on the host display) I see a grub screen to select a >>> particular kernel, followed by the usual console output during bootup >>> before X starts. However, when running with passthrough enabled, the >>> guest vm's monitor (Samsung U28D590) shows nothing until X starts - >>> there is no grub screen and no console output. >>> >>> Before I had the nvidia binary driver installed in the guest, I had some >>> console output while booting but still no grub screen. >>> >>> Is there some way I can see everything including the grub screen, or is >>> it normal not to see that in the guest? >> >> It is normal on my Quadro M5000 - these cards are not supported as primary >> display with passthrough. This might be something to do with ROM, but I was >> not successful trying to investigate further. To compensate for this all my >> virtual machines have serial console, so I can do "virsh console" >> >> >> B. >> > > Thanks for the confirmation Bronek - it's good to know I'm not the only > one seeing this. I'll give it a try with serial console. > For others searching about this issue, Bronek's idea to use serial console for grub and system boot messages was a good one. For "pure" qemu users, it works (for me) like this: first note that the qemu gui interface has a "serial0" option in the View menu. Selecting the serial0 option early enough displays the grub screen with which you may interact to select which kernel to boot. After that will be mainly nothing of interest though (in my case: error: no suitable video mode found. Booting in blind mode). To see all the kernel boot messages too, the guest's kernel command line must also include something like: console=ttyS0,115200n8 (38400n8 also worked - probably other speeds too) I think most people might want to add this via /etc/default/grub but since I was experimenting and wanted to try things with a unique grub entry (rather than all grub entries) I added it to a dedicated grub menuentry in /etc/grub.d/40_custom so that my kernel command line looked like this: linux /boot/vmlinuz-generic root=/dev/sda2 ro console=ttyS0,115200n8 Now all the expected boot output appears in qemu's serial0 window. The only problem with using serial0 window is that it's not scrollable. An alternative is to add "-serial mon:stdio" somewhere in the qemu command/script. Then the grub screen and boot output appears in the terminal used to run qemu. Note that the -serial option is not compatible with -daemonize". chris ___ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
Re: [vfio-users] vga passthrough works but no grub screen for linux guest
On 30/6/19 11:07 pm, Bronek Kozicki wrote: > On Sun, 30 Jun 2019, at 1:41 PM, Christoph Willing wrote: >> I have vga passthrough working with a linux guest running in qemu-3.1.0 >> on a host with two Nvidia Quadro K600 cards and the nvidia binary driver >> 430.26 installed. A dedicated keyboard & mouse is also passed through >> successfully so, in general, I'm pretty happy with the setup but ... >> >> when I use OVMF and run the guest without passthrough (just a regular >> qemu vm running on the host display) I see a grub screen to select a >> particular kernel, followed by the usual console output during bootup >> before X starts. However, when running with passthrough enabled, the >> guest vm's monitor (Samsung U28D590) shows nothing until X starts - >> there is no grub screen and no console output. >> >> Before I had the nvidia binary driver installed in the guest, I had some >> console output while booting but still no grub screen. >> >> Is there some way I can see everything including the grub screen, or is >> it normal not to see that in the guest? > > It is normal on my Quadro M5000 - these cards are not supported as primary > display with passthrough. This might be something to do with ROM, but I was > not successful trying to investigate further. To compensate for this all my > virtual machines have serial console, so I can do "virsh console" > > > B. > Thanks for the confirmation Bronek - it's good to know I'm not the only one seeing this. I'll give it a try with serial console. chris ___ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
Re: [vfio-users] vga passthrough works but no grub screen for linux guest
On Sun, 30 Jun 2019, at 1:41 PM, Christoph Willing wrote: > I have vga passthrough working with a linux guest running in qemu-3.1.0 > on a host with two Nvidia Quadro K600 cards and the nvidia binary driver > 430.26 installed. A dedicated keyboard & mouse is also passed through > successfully so, in general, I'm pretty happy with the setup but ... > > when I use OVMF and run the guest without passthrough (just a regular > qemu vm running on the host display) I see a grub screen to select a > particular kernel, followed by the usual console output during bootup > before X starts. However, when running with passthrough enabled, the > guest vm's monitor (Samsung U28D590) shows nothing until X starts - > there is no grub screen and no console output. > > Before I had the nvidia binary driver installed in the guest, I had some > console output while booting but still no grub screen. > > Is there some way I can see everything including the grub screen, or is > it normal not to see that in the guest? It is normal on my Quadro M5000 - these cards are not supported as primary display with passthrough. This might be something to do with ROM, but I was not successful trying to investigate further. To compensate for this all my virtual machines have serial console, so I can do "virsh console" B. -- Bronek Kozicki b...@spamcop.net ___ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
[vfio-users] vga passthrough works but no grub screen for linux guest
I have vga passthrough working with a linux guest running in qemu-3.1.0 on a host with two Nvidia Quadro K600 cards and the nvidia binary driver 430.26 installed. A dedicated keyboard & mouse is also passed through successfully so, in general, I'm pretty happy with the setup but ... when I use OVMF and run the guest without passthrough (just a regular qemu vm running on the host display) I see a grub screen to select a particular kernel, followed by the usual console output during bootup before X starts. However, when running with passthrough enabled, the guest vm's monitor (Samsung U28D590) shows nothing until X starts - there is no grub screen and no console output. Before I had the nvidia binary driver installed in the guest, I had some console output while booting but still no grub screen. Is there some way I can see everything including the grub screen, or is it normal not to see that in the guest? Thanks for any insights or suggestions, chris ___ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
