Another missing stub hypercall is HVC_SOFT_RESTART. It turns out that it is pretty easy to implement in terms of HVC_RESET_VECTORS (since it needs to turn the MMU off). Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm64/kvm/hyp-init.S | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S index b53e95efc1c5..128d6e9732b9 100644 --- a/arch/arm64/kvm/hyp-init.S +++ b/arch/arm64/kvm/hyp-init.S @@ -129,21 +129,36 @@ ENTRY(__kvm_handle_stub_hvc) mrs x0, vbar_el2 b exit +1: cmp x0, #HVC_SOFT_RESTART + b.ne 1f + + /* This is where we're about to jump, staying at EL2 */ + msr elr_el2, x1 + mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) + msr spsr_el2, x0 + + /* Shuffle the arguments, and don't come back */ + mov x0, x2 + mov x1, x3 + mov x2, x4 + b reset + 1: cmp x0, #HVC_RESET_VECTORS b.ne 1f +reset: /* - * Reset kvm back to the hyp stub. + * Reset kvm back to the hyp stub. Do not clobber x0-x4 in + * case we coming via HVC_SOFT_RESTART. */ - /* We're now in idmap, disable MMU */ - mrs x0, sctlr_el2 - ldr x1, =SCTLR_ELx_FLAGS - bic x0, x0, x1 // Clear SCTL_M and etc - msr sctlr_el2, x0 + mrs x5, sctlr_el2 + ldr x6, =SCTLR_ELx_FLAGS + bic x5, x5, x6 // Clear SCTL_M and etc + msr sctlr_el2, x5 isb /* Install stub vectors */ - adr_l x0, __hyp_stub_vectors - msr vbar_el2, x0 + adr_l x5, __hyp_stub_vectors + msr vbar_el2, x5 b exit 1: mov x0, #-1 -- 2.11.0
