KVM: PPC: BOOKE: Guest and hardware visible debug registers are same

Guest visible debug register and hardware visible debug registers are
same, so ther is no need to have arch->shadow_dbg_reg, instead use
arch->dbg_reg.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_host.h

@@ -585,8 +585,6 @@ struct kvm_vcpu_arch {
 	u32 crit_save;
 	/* guest debug registers*/
 	struct debug_reg dbg_reg;
-	/* hardware visible debug registers when in guest state */
-	struct debug_reg shadow_dbg_reg;
 #endif
 	gpa_t paddr_accessed;
 	gva_t vaddr_accessed;

arch/powerpc/kvm/booke.c

@@ -668,10 +668,10 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 #endif
 
 	/* Switch to guest debug context */
-	debug = vcpu->arch.shadow_dbg_reg;
+	debug = vcpu->arch.dbg_reg;
 	switch_booke_debug_regs(&debug);
 	debug = current->thread.debug;
-	current->thread.debug = vcpu->arch.shadow_dbg_reg;
+	current->thread.debug = vcpu->arch.dbg_reg;
 
 	vcpu->arch.pgdir = current->mm->pgd;
 	kvmppc_fix_ee_before_entry();
@@ -732,7 +732,7 @@ static int emulation_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
 static int kvmppc_handle_debug(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
-	struct debug_reg *dbg_reg = &(vcpu->arch.shadow_dbg_reg);
+	struct debug_reg *dbg_reg = &(vcpu->arch.dbg_reg);
 	u32 dbsr = vcpu->arch.dbsr;
 
 	/* Clear guest dbsr (vcpu->arch.dbsr) */
@@ -1848,7 +1848,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 	int n, b = 0, w = 0;
 
 	if (!(dbg->control & KVM_GUESTDBG_ENABLE)) {
-		vcpu->arch.shadow_dbg_reg.dbcr0 = 0;
+		vcpu->arch.dbg_reg.dbcr0 = 0;
 		vcpu->guest_debug = 0;
 		kvm_guest_protect_msr(vcpu, MSR_DE, false);
 		return 0;
@@ -1856,15 +1856,13 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 
 	kvm_guest_protect_msr(vcpu, MSR_DE, true);
 	vcpu->guest_debug = dbg->control;
-	vcpu->arch.shadow_dbg_reg.dbcr0 = 0;
-	/* Set DBCR0_EDM in guest visible DBCR0 register. */
-	vcpu->arch.dbg_reg.dbcr0 = DBCR0_EDM;
+	vcpu->arch.dbg_reg.dbcr0 = 0;
 
 	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-		vcpu->arch.shadow_dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC;
+		vcpu->arch.dbg_reg.dbcr0 |= DBCR0_IDM | DBCR0_IC;
 
 	/* Code below handles only HW breakpoints */
-	dbg_reg = &(vcpu->arch.shadow_dbg_reg);
+	dbg_reg = &(vcpu->arch.dbg_reg);
 
 #ifdef CONFIG_KVM_BOOKE_HV
 	/*

arch/powerpc/kvm/booke_emulate.c

@@ -293,6 +293,8 @@ int kvmppc_booke_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val)
 		break;
 	case SPRN_DBCR0:
 		*spr_val = vcpu->arch.dbg_reg.dbcr0;
+		if (vcpu->guest_debug)
+			*spr_val = *spr_val | DBCR0_EDM;
 		break;
 	case SPRN_DBCR1:
 		*spr_val = vcpu->arch.dbg_reg.dbcr1;