arm: qemu: disable the EFI workaround for older GRUB

The QEMU/mach-virt targeted port of u-boot currently only runs on
QEMU under TCG emulation, which does not model the caches at all,
and so no users can exist that are relying on the GRUB hack for
EFI boot.

We will shortly enable support for running under KVM, but the GRUB
hack (which disables all caches without doing cache cleaning by VA
during ExitBootServices()) is likely to cause more problems than it
solves, given that KVM hosts require correct maintenance if they
incorporate non-architected system caches.

So let's disable the GRUB hack by default on the QEMU/mach-virt
port.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/configs/qemu_arm_defconfig b/configs/qemu_arm_defconfig
index 75bdce7708c78236bc06694487690a542fc73955..1d2b4437cb071739242bb801e1bb9c5f05d7ee56 100644 (file)
--- a/configs/qemu_arm_defconfig
+++ b/configs/qemu_arm_defconfig
@@ -47,3 +47,4 @@ CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_PCI=y
+# CONFIG_EFI_GRUB_ARM32_WORKAROUND is not set