Hello again, > For performance, I expect there will be a hit vs running on baremetal, > but I don't know the extent. I don't know if we suffer from the same > problem you mention for Xen, but I don't see why it would be the case > either (perhaps the link retrains at a lower speed?). When using xen, at least some users experience that after a guest which used VGA-passthrough powered down, the host has to be rebooted as well before the guest is started again, since otherwise, the graphics card is in some kind of half-initialized state (or so I read) and won't do 3D acceleration. Also, nVidia is said to be a lot more problematic than AMD in xen-land. > Yes, with the correction of s/should/might/. 3D acceleration might also > work. Generally if you assign a passthrough graphics as a secondary > device it will only work once you load the vendor driver stack (ex. AMD > Catalyst), at which point the emulated graphics is disabled and the > passthrough graphics becomes the primary for the guest. Thanks, I just tried with Windows 7. When the host's integrated CPU (set as non-primary display) was used as secondary in the guest, driver installation caused a bluescreen. I also tried the equivalent with Linux Mint, but when the emulated std-vga and the passthrough'd integrated GPU both are present, both screens show garbage. When passing through the integrated GPU already during Mint installation, the livecd makes the screens flicker, and then I'm told X failed to detect screen resolutions. I haven't looked further into this. The latter I did with a command line like this: qemu-system-x86_64 -enable-kvm -M q35 -m 1024 -cpu host -smp 2,sockets=1,cores=2,threads=1 -bios /home/gustav/myroot/bios.bin -vga std -vnc :0 -device ioh3420,bus=pcie.0,addr=1c.0,multifunction=on,port=1,chassis=1,id=root.1 -device vfio-pci,host=00:01.0,bus=root.1,addr=00.0,multifunction=on -device vfio-pci,host=00:01.1,bus=root.1,addr=00.1 -device ahci,bus=pcie.0,id=ahci -drive file=/home/gustav/linuxmint-15-xfce-dvd-64bit-rc.iso,id=isocd -device ide-cd,bus=ahci.1,drive=isocd While the guest was running, there were lines saying "vcpu0 ignored rdmsr", "vcpu0 ignored wrmsr", "vcpu0 unimplemented HWCR wrmsr" and vcpu0 unimplemented perfctr wrmsr" in dmesg. Relevant dmesg section if the integrated GPU is set as the host primary: http://pastebin.com/DjALp678 Relevant dmesg section if the dedicated GPU is set as the host primary: http://pastebin.com/7UX3xQtM I don't know whether this is relevant. Thank you very much for your help! -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
