Commit 7a26e1f5 authored by Marc Zyngier's avatar Marc Zyngier Committed by Oliver Upton
Browse files

arm64: Don't enable VHE for the kernel if OVERRIDE_HVHE is set 



If the OVERRIDE_HVHE SW override is set (as a precursor of
the KVM_HVHE capability), do not enable VHE for the kernel
and drop to EL1 as if VHE was either disabled or unavailable.

Further changes will enable VHE at EL2 only, with the kernel
still running at EL1.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230609162200.2024064-6-maz@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent e2d6c906

arch/arm64/kernel/hyp-stub.S

+9 −1
Original line number Diff line number Diff line
@@ -82,7 +82,15 @@ SYM_CODE_START_LOCAL(__finalise_el2) 
	tbnz	x1, #0, 1f



	// Needs to be VHE capable, obviously

	check_override id_aa64mmfr1 ID_AA64MMFR1_EL1_VH_SHIFT 2f 1f x1 x2

	check_override id_aa64mmfr1 ID_AA64MMFR1_EL1_VH_SHIFT 0f 1f x1 x2



0:	// Check whether we only want the hypervisor to run VHE, not the kernel

	adr_l	x1, arm64_sw_feature_override

	ldr	x2, [x1, FTR_OVR_VAL_OFFSET]

	ldr	x1, [x1, FTR_OVR_MASK_OFFSET]

	and	x2, x2, x1

	ubfx	x2, x2, #ARM64_SW_FEATURE_OVERRIDE_HVHE, #4

	cbz	x2, 2f



1:	mov_q	x0, HVC_STUB_ERR

	eret