| Message ID | 20200606171534.736365-5-ardb@kernel.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fixes for running U-boot under QEMU/KVM | expand |
On 6/6/20 7:15 PM, 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 at kernel.org> This patch could be merged with 2/5. You are changing the same defconfig. Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de> > --- > configs/qemu_arm_defconfig | 1 + > 1 file changed, 1 insertion(+) > > 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 >
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
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> --- configs/qemu_arm_defconfig | 1 + 1 file changed, 1 insertion(+)