KVM: PPC: booke: Added debug handler

Installed debug handler will be used for guest debug support
and debug facility emulation features (patches for these
features will follow this patch).
Signed-off-by: Liu Yu <yu.liu@freescale.com>
[bharat.bhushan@freescale.com: Substantial changes]
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_host.h

@@ -504,6 +504,7 @@ struct kvm_vcpu_arch {
 	u32 tlbcfg[4];
 	u32 mmucfg;
 	u32 epr;
+	u32 crit_save;
 	struct kvmppc_booke_debug_reg dbg_reg;
 #endif
 	gpa_t paddr_accessed;

arch/powerpc/kernel/asm-offsets.c

@@ -596,6 +596,7 @@ int main(void)
 	DEFINE(VCPU_LAST_INST, offsetof(struct kvm_vcpu, arch.last_inst));
 	DEFINE(VCPU_FAULT_DEAR, offsetof(struct kvm_vcpu, arch.fault_dear));
 	DEFINE(VCPU_FAULT_ESR, offsetof(struct kvm_vcpu, arch.fault_esr));
+	DEFINE(VCPU_CRIT_SAVE, offsetof(struct kvm_vcpu, arch.crit_save));
 #endif /* CONFIG_PPC_BOOK3S */
 #endif /* CONFIG_KVM */
 

arch/powerpc/kvm/booke_interrupts.S

@@ -54,8 +54,7 @@
                        (1<<BOOKE_INTERRUPT_DTLB_MISS) | \
                        (1<<BOOKE_INTERRUPT_ALIGNMENT))
 
-.macro KVM_HANDLER ivor_nr scratch srr0
-_GLOBAL(kvmppc_handler_\ivor_nr)
+.macro __KVM_HANDLER ivor_nr scratch srr0
 	/* Get pointer to vcpu and record exit number. */
 	mtspr	\scratch , r4
 	mfspr   r4, SPRN_SPRG_THREAD
@@ -76,6 +75,43 @@ _GLOBAL(kvmppc_handler_\ivor_nr)
 	bctr
 .endm
 
+.macro KVM_HANDLER ivor_nr scratch srr0
+_GLOBAL(kvmppc_handler_\ivor_nr)
+	__KVM_HANDLER \ivor_nr \scratch \srr0
+.endm
+
+.macro KVM_DBG_HANDLER ivor_nr scratch srr0
+_GLOBAL(kvmppc_handler_\ivor_nr)
+	mtspr   \scratch, r4
+	mfspr	r4, SPRN_SPRG_THREAD
+	lwz	r4, THREAD_KVM_VCPU(r4)
+	stw	r3, VCPU_CRIT_SAVE(r4)
+	mfcr	r3
+	mfspr	r4, SPRN_CSRR1
+	andi.	r4, r4, MSR_PR
+	bne	1f
+	/* debug interrupt happened in enter/exit path */
+	mfspr   r4, SPRN_CSRR1
+	rlwinm  r4, r4, 0, ~MSR_DE
+	mtspr   SPRN_CSRR1, r4
+	lis	r4, 0xffff
+	ori	r4, r4, 0xffff
+	mtspr	SPRN_DBSR, r4
+	mfspr	r4, SPRN_SPRG_THREAD
+	lwz	r4, THREAD_KVM_VCPU(r4)
+	mtcr	r3
+	lwz     r3, VCPU_CRIT_SAVE(r4)
+	mfspr   r4, \scratch
+	rfci
+1:	/* debug interrupt happened in guest */
+	mtcr	r3
+	mfspr	r4, SPRN_SPRG_THREAD
+	lwz	r4, THREAD_KVM_VCPU(r4)
+	lwz     r3, VCPU_CRIT_SAVE(r4)
+	mfspr   r4, \scratch
+	__KVM_HANDLER \ivor_nr \scratch \srr0
+.endm
+
 .macro KVM_HANDLER_ADDR ivor_nr
 	.long	kvmppc_handler_\ivor_nr
 .endm
@@ -100,7 +136,7 @@ KVM_HANDLER BOOKE_INTERRUPT_FIT SPRN_SPRG_RSCRATCH0 SPRN_SRR0
 KVM_HANDLER BOOKE_INTERRUPT_WATCHDOG SPRN_SPRG_RSCRATCH_CRIT SPRN_CSRR0
 KVM_HANDLER BOOKE_INTERRUPT_DTLB_MISS SPRN_SPRG_RSCRATCH0 SPRN_SRR0
 KVM_HANDLER BOOKE_INTERRUPT_ITLB_MISS SPRN_SPRG_RSCRATCH0 SPRN_SRR0
-KVM_HANDLER BOOKE_INTERRUPT_DEBUG SPRN_SPRG_RSCRATCH_CRIT SPRN_CSRR0
+KVM_DBG_HANDLER BOOKE_INTERRUPT_DEBUG SPRN_SPRG_RSCRATCH_CRIT SPRN_CSRR0
 KVM_HANDLER BOOKE_INTERRUPT_SPE_UNAVAIL SPRN_SPRG_RSCRATCH0 SPRN_SRR0
 KVM_HANDLER BOOKE_INTERRUPT_SPE_FP_DATA SPRN_SPRG_RSCRATCH0 SPRN_SRR0
 KVM_HANDLER BOOKE_INTERRUPT_SPE_FP_ROUND SPRN_SPRG_RSCRATCH0 SPRN_SRR0