> Hi, > I'm trying to use PCI passthrough to give an NVIDA GPU to a windows vm > with qemu-kvm. I have a Windows 7 64bit VM working well under Fedora > 25 with an Nvidia GPU GTX 750Ti. But when I tried Windows 7 32bit, the > OVMF UEFI could not load the Windows ISO.
Main issue: No 32 Bits Windows supports UEFI Boot. It only supports it in 64 Bits versions. Use SeaBIOS.
> I have some questions： > *. How can I passthrough a GPU card to windows 7 32bit system?
With SeaBIOS, and using -device vfio-pci with x-vga=on. Look for more detailed instructions.
> *. Is OVMF UEFI firmware necessary for PCI GPU passthrough? I have > tried with SeaBIOS, but the gpu card could not start with code 10.
No, but it is the easiest way. Read what VGA Arbitration is.
> *. Does the GPU ROM must suppport UEFI?
For Primary VGA Passthrough with UEFI Boot, yes. Legacy VBIOS works for SeaBIOS, and every existing Video Card should have it. I don't know if GeForces can be used with Secondary VGA Passthrough. That means without using the ROM, it gets initialized solely by the Drivers when the OS loads.