diff mbox series

[v3,4/5] arm: qemu: disable the EFI workaround for older GRUB

Message ID 20200707100711.7446-5-ardb@kernel.org
State Superseded
Headers show
Series Fixes for running U-boot under QEMU/KVM | expand

Commit Message

Ard Biesheuvel July 7, 2020, 10:07 a.m. UTC 
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 at kernel.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 configs/qemu_arm_defconfig | 1 +
 1 file changed, 1 insertion(+)

Comments

Tom Rini July 29, 2020, 1:43 p.m. UTC | #1 
On Tue, Jul 07, 2020 at 12:07:10PM +0200, Ard Biesheuvel wrote:

> 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>


Applied to u-boot/master, thanks!

-- 
Tom
diff mbox series

Patch

diff --git a/configs/qemu_arm_defconfig b/configs/qemu_arm_defconfig
index 75bdce7708c7..1d2b4437cb07 100644
--- 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