ARM: KVM: Implement HVC_SOFT_RESTART in the init code

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).

Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>

diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index fb33609..e53360d 100644 (file)
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -127,8 +127,22 @@ ENTRY(__kvm_handle_stub_hvc)
        mrc     p15, 4, r0, c12, c0, 0  @ get HVBAR
        b       exit
 
+1:     cmp     r0, #HVC_SOFT_RESTART
+       bne     1f
+
+       /* The target is expected in r1 */
+       msr     ELR_hyp, r1
+       mrs     r0, cpsr
+       bic     r0, r0, #MODE_MASK
+       orr     r0, r0, #HYP_MODE
+THUMB( orr     r0, r0, #PSR_T_BIT      )
+       msr     spsr_cxsf, r0
+       b       reset
+
 1:     cmp     r0, #HVC_RESET_VECTORS
        bne     1f
+
+reset:
        /* We're now in idmap, disable MMU */
        mrc     p15, 4, r1, c1, c0, 0   @ HSCTLR
        ldr     r0, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I)