Re: comment 14, "is there a way to fix vbeshim instead of reverting RO limitation that commit introduced?":
I don't think so; please see my earlier comments 15 and 17. To elaborate: If a user wants to boot Windows 7 on OVMF, they have *three* options: (1) Build the SeaBIOS CSM (CONFIG_CSM=y), and embed it into OVMF, like described above. Then, boot Windows 7 in *Legacy Mode*. --> Windows 7 will think that it runs on a plain BIOS machine. The VBE Services will be provided to Windows 7 by (a) the edk2 CSM infrastructure, (b) the SeaBIOS CSM, and (c) the VGABIOS PCI oprom together. (2) Build the SeaBIOS CSM (CONFIG_CSM=y), and embed it into OVMF, like described above. Then, boot Windows 7 in *UEFI Mode*. --> Windows 7 will think that it runs on a UEFI machine, *but* because Windows 7 has a bug, it will want to invoke VBE services nonetheless. The VBE Services will be provided to Windows 7 by (a) the edk2 CSM infrastructure, (b) the SeaBIOS CSM, and (c) the VGABIOS PCI oprom together. (3) Build OVMF without the SeaBIOS CSM, then boot Windows 7 in UEFI Mode. --> Windows 7 will think that it runs on a UEFI machine, *but* because Windows 7 has a bug, it will want to invoke VBE services nonetheless. The VBE Services will be provided to Windows 7 by the VBE Shim that OVMF installs during boot. Option #1 and option #2 no longer work because the CSM infrastructure in edk2 needs to be able to write 0xc0000. Option #3 no longer works because OVMF needs to put the VBE Shim into place at 0xc0000. Basically, Windows 7 wants to find the VBE services at 0xc0000, regardless of the method that it is booted with, ie. Legacy or UEFI. (As I said, this is a Windows 7 bug.) If that memory area is not writeable to the guest, then OVMF cannot satisfy the (buggy) Windows 7 requirement, using either of options #1, #2 or #3. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1715700 Title: Windows 7 guest won't boot on qemu 2.10 (works on 2.9) Status in QEMU: New Bug description: Qemu version: 2.10 stable. Guest: Windows 7 SP1 x64, virtio drivers are already installed in the guest. Command line: qemu-system-x86_64 \ -nodefaults \ -nodefconfig \ -machine type=q35,accel=kvm \ -enable-kvm \ -cpu host \ -m 2048 \ -vga virtio \ -boot menu=on \ -smbios file=/path/dmidecode_BIOS.bin \ -acpitable file=/path/acpi_slic.bin \ -bios /path/OVMF_CODE.fd \ -net none \ -drive if=virtio,media=disk,file=/media/win7.qcow2 \ -device pcie-root-port \ -device ich9-usb-ehci1 \ -device ich9-usb-uhci1 \ -device ich9-usb-uhci2 \ -device ich9-usb-uhci3 Windows hangs at boot with waving flag screen (flag doesn't freeze, keeps waving indefinitely). Same command line boots fine with Qemu 2.9. I tried changing machine type to pc-q35-2.9 - same result. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1715700/+subscriptions
