Host support for L2

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 3e3b694..ced650a 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -151,7 +151,9 @@ static void update_sp(struct kvm_vcpu *vcpu, u64 val)
        if (!vcpu_shadow_reg(vcpu, SP_EL2))
                vcpu->arch.guest_sp = regs->sp_el1;
        vcpu_shadow_reg(vcpu, SP_EL2) = val;
+       printk("STACK: shadow SP_EL2 is now %llx\n", val);
        regs->sp_el1 = vcpu_shadow_reg(vcpu, SP_EL2);
+       printk("STACK: Set SP_EL1 too to SP_EL2\n");
 }

 static void switch_sp(struct kvm_vcpu *vcpu, bool to_low) {
@@ -159,10 +161,14 @@ static void switch_sp(struct kvm_vcpu *vcpu, bool to_low) {

        if (to_low) {
                vcpu->arch.guest_sp = regs->sp_el1;
+               printk("STACK: Save SP_EL1 to guest's: %llx\n", regs->sp_el1);
                regs->sp_el1 = vcpu_shadow_reg(vcpu, SP_EL2);
+               printk("STACK: Set SP_EL1 to shadow SP_EL2: %llx\n", regs->sp_el1);
        } else {
                vcpu_shadow_reg(vcpu, SP_EL2) = regs->sp_el1;
+               printk("STACK: Save SP_EL1 to shadow SP_EL2: %llx\n", regs->sp_el1);
                regs->sp_el1 = vcpu->arch.guest_sp;
+               printk("STACK: Set SP_EL1 back to guest's: %llx\n", regs->sp_el1);
        }
 }

@@ -226,16 +232,32 @@ static int kvm_inject_nested(struct kvm_vcpu *vcpu)

 /* If L1 lowvisor changes EL2 registers, we need to change corresponding
  * EL1 registers immediately */
-static void emulate_msr(struct kvm_vcpu *vcpu, int sreg_num, u64 *sregp, u64 val)
+static void emulate_msr(struct kvm_vcpu *vcpu, int sreg_num, bool is_el2, u64 *sregp, u64 val)
 {
-       if (sreg_num == SP_EL2)
-               update_sp(vcpu, val);
-       else if (sreg_num == TTBR0_EL2)
-               update_ttbr(vcpu, val);
-       else if (sreg_num == SCTLR_EL2)
-               update_sctlr(vcpu, val);
-       else
-               *sregp = val;
+       if (is_el2) {
+               if (sreg_num == SP_EL2)
+                       update_sp(vcpu, val);
+               else if (sreg_num == TTBR0_EL2)
+                       update_ttbr(vcpu, val);
+               else if (sreg_num == SCTLR_EL2)
+                       update_sctlr(vcpu, val);
+               else
+                       *sregp = val;
+       } else {
+               if (sreg_num == SP_EL1) {
+                       printk("Change L2's stack pointer, not L1 low's: %llx\n", val);
+                       vcpu->arch.guest_sp = val;
+               } else if (sreg_num == TTBR0_EL1) {
+                       vcpu->arch.guest_ttbr0 = val;
+                       printk("Change L2's TTBR. %llx\n", val);
+               }
+               else if (sreg_num == SCTLR_EL1) {
+                       vcpu->arch.guest_sctlr = val;
+                       printk("Change L2's SCTLR. %llx\n", val);
+               }
+               else
+                       *sregp = val;
+       }
 }

 static int emulate_mov_sysreg(struct kvm_vcpu *vcpu, u16 imm, bool is_msr)
@@ -246,6 +268,7 @@ static int emulate_mov_sysreg(struct kvm_vcpu *vcpu, u16 imm, bool is_msr)
        u32 sreg_num = (imm & HE_SYSREG_MASK)>>HE_SYSREG_SHIFT;
        bool is_imm = imm & HE_IMM;

+       printk("%s\n", __func__);
        gpregp = &vcpu->arch.ctxt.gp_regs.regs.regs[gpreg_num];
        if (unlikely(is_imm))
                *gpregp = imm & HE_IMM_MASK;
@@ -260,7 +283,7 @@ static int emulate_mov_sysreg(struct kvm_vcpu *vcpu, u16 imm, bool is_msr)

        print_encoding(vcpu, is_msr, is_imm, imm&HE_EL2, sreg_num, gpreg_num, *gpregp);
        if (is_msr)
-               emulate_msr(vcpu, sreg_num, sregp, *gpregp);
+               emulate_msr(vcpu, sreg_num, imm&HE_EL2, sregp, *gpregp);
        else
                *gpregp = *sregp;

@@ -452,6 +475,7 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
        u32 hsr = kvm_vcpu_get_hsr(vcpu);
        u8 hsr_ec = hsr >> ESR_ELx_EC_SHIFT;

+       printk("TRAP! exit_handler: %x\n", hsr_ec);
        if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
            !arm_exit_handlers[hsr_ec]) {
                kvm_err("Unknown exception class: hsr: %#08x -- %s\n",