On Fri, May 26, 2023 at 03:33:36PM +0100, Marc Zyngier wrote: > 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: Marc Zyngier <maz@xxxxxxxxxx> > --- > arch/arm64/kernel/hyp-stub.S | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S > index 9439240c3fcf..5c71e1019545 100644 > --- a/arch/arm64/kernel/hyp-stub.S > +++ b/arch/arm64/kernel/hyp-stub.S > @@ -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 nit: is applying the mask even necessary? I get it in the context of an overlay on top of an ID register, but the software features are more of a synthetic ID register in their own right. Same nit applies to the kaslr case as well. > + ubfx x2, x2, #ARM64_SW_FEATURE_OVERRIDE_HVHE, #4 > + cbz x2, 2f > > 1: mov_q x0, HVC_STUB_ERR > eret > -- > 2.34.1 > -- Thanks, Oliver
