powerpc/kvm: common sw breakpoint instr across ppc

This patch extends the use of illegal instruction as software
breakpoint instruction across the ppc platform. Patch extends
booke program interrupt code to support software breakpoint.
Signed-off-by: NMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
[agraf: Fix bookehv]
Signed-off-by: NAlexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_booke.h

@@ -33,8 +33,6 @@
 #define EHPRIV_OC_SHIFT			11
 /* "ehpriv 1" : ehpriv with OC = 1 is used for debug emulation */
 #define EHPRIV_OC_DEBUG			1
-#define KVMPPC_INST_EHPRIV_DEBUG	(KVMPPC_INST_EHPRIV | \
-					 (EHPRIV_OC_DEBUG << EHPRIV_OC_SHIFT))
 
 static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val)
 {

arch/powerpc/kvm/booke.c

@@ -994,6 +994,11 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	case BOOKE_INTERRUPT_HV_PRIV:
 		emulated = kvmppc_get_last_inst(vcpu, false, &last_inst);
 		break;
+	case BOOKE_INTERRUPT_PROGRAM:
+		/* SW breakpoints arrive as illegal instructions on HV */
+		if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
+			emulated = kvmppc_get_last_inst(vcpu, false, &last_inst);
+		break;
 	default:
 		break;
 	}
@@ -1071,6 +1076,18 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		break;
 
 	case BOOKE_INTERRUPT_PROGRAM:
+		if ((vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) &&
+			(last_inst == KVMPPC_INST_SW_BREAKPOINT)) {
+			/*
+			 * We are here because of an SW breakpoint instr,
+			 * so lets return to host to handle.
+			 */
+			r = kvmppc_handle_debug(run, vcpu);
+			run->exit_reason = KVM_EXIT_DEBUG;
+			kvmppc_account_exit(vcpu, DEBUG_EXITS);
+			break;
+		}
+
 		if (vcpu->arch.shared->msr & (MSR_PR | MSR_GS)) {
 			/*
 			 * Program traps generated by user-level software must
@@ -1647,7 +1664,7 @@ int kvmppc_get_one_reg(struct kvm_vcpu *vcpu, u64 id,
 		*val = get_reg_val(id, vcpu->arch.tsr);
 		break;
 	case KVM_REG_PPC_DEBUG_INST:
-		*val = get_reg_val(id, KVMPPC_INST_EHPRIV_DEBUG);
+		*val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT);
 		break;
 	case KVM_REG_PPC_VRSAVE:
 		*val = get_reg_val(id, vcpu->arch.vrsave);

arch/powerpc/kvm/bookehv_interrupts.S

@@ -238,7 +238,7 @@ kvm_handler BOOKE_INTERRUPT_EXTERNAL, EX_PARAMS(GEN), \
 kvm_handler BOOKE_INTERRUPT_ALIGNMENT, EX_PARAMS(GEN), \
 	SPRN_SRR0, SPRN_SRR1,(NEED_DEAR | NEED_ESR)
 kvm_handler BOOKE_INTERRUPT_PROGRAM, EX_PARAMS(GEN), \
-	SPRN_SRR0, SPRN_SRR1,NEED_ESR
+	SPRN_SRR0, SPRN_SRR1, (NEED_ESR | NEED_EMU)
 kvm_handler BOOKE_INTERRUPT_FP_UNAVAIL, EX_PARAMS(GEN), \
 	SPRN_SRR0, SPRN_SRR1, 0
 kvm_handler BOOKE_INTERRUPT_AP_UNAVAIL, EX_PARAMS(GEN), \
@@ -348,7 +348,7 @@ kvm_handler BOOKE_INTERRUPT_INST_STORAGE, SPRN_SRR0, SPRN_SRR1, NEED_ESR
 kvm_handler BOOKE_INTERRUPT_EXTERNAL, SPRN_SRR0, SPRN_SRR1, 0
 kvm_handler BOOKE_INTERRUPT_ALIGNMENT, \
 	SPRN_SRR0, SPRN_SRR1, (NEED_DEAR | NEED_ESR)
-kvm_handler BOOKE_INTERRUPT_PROGRAM, SPRN_SRR0, SPRN_SRR1, NEED_ESR
+kvm_handler BOOKE_INTERRUPT_PROGRAM, SPRN_SRR0, SPRN_SRR1, (NEED_ESR | NEED_EMU)
 kvm_handler BOOKE_INTERRUPT_FP_UNAVAIL, SPRN_SRR0, SPRN_SRR1, 0
 kvm_handler BOOKE_INTERRUPT_SYSCALL, SPRN_SRR0, SPRN_SRR1, 0
 kvm_handler BOOKE_INTERRUPT_AP_UNAVAIL, SPRN_SRR0, SPRN_SRR1, 0