kvm: ppc: bookehv: Save restore SPRN_SPRG9 on guest entry exit

SPRN_SPRG is used by debug interrupt handler, so this is required for
debug support.

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

arch/powerpc/include/asm/kvm_host.h

@@ -587,6 +587,7 @@ struct kvm_vcpu_arch {
 	u32 mmucfg;
 	u32 eptcfg;
 	u32 epr;
+	u64 sprg9;
 	u32 pwrmgtcr0;
 	u32 crit_save;
 	/* guest debug registers*/

arch/powerpc/kernel/asm-offsets.c

@@ -668,6 +668,7 @@ int main(void)
 	DEFINE(VCPU_LR, offsetof(struct kvm_vcpu, arch.lr));
 	DEFINE(VCPU_CTR, offsetof(struct kvm_vcpu, arch.ctr));
 	DEFINE(VCPU_PC, offsetof(struct kvm_vcpu, arch.pc));
+	DEFINE(VCPU_SPRG9, offsetof(struct kvm_vcpu, arch.sprg9));
 	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));

arch/powerpc/kvm/bookehv_interrupts.S

@@ -398,6 +398,7 @@ _GLOBAL(kvmppc_resume_host)
 #ifdef CONFIG_64BIT
 	PPC_LL	r3, PACA_SPRG_VDSO(r13)
 #endif
+	mfspr	r5, SPRN_SPRG9
 	PPC_STD(r6, VCPU_SHARED_SPRG4, r11)
 	mfspr	r8, SPRN_SPRG6
 	PPC_STD(r7, VCPU_SHARED_SPRG5, r11)
@@ -405,6 +406,7 @@ _GLOBAL(kvmppc_resume_host)
 #ifdef CONFIG_64BIT
 	mtspr	SPRN_SPRG_VDSO_WRITE, r3
 #endif
+	PPC_STD(r5, VCPU_SPRG9, r4)
 	PPC_STD(r8, VCPU_SHARED_SPRG6, r11)
 	mfxer	r3
 	PPC_STD(r9, VCPU_SHARED_SPRG7, r11)
@@ -639,7 +641,9 @@ lightweight_exit:
 	mtspr	SPRN_SPRG5W, r6
 	PPC_LD(r8, VCPU_SHARED_SPRG7, r11)
 	mtspr	SPRN_SPRG6W, r7
+	PPC_LD(r5, VCPU_SPRG9, r4)
 	mtspr	SPRN_SPRG7W, r8
+	mtspr	SPRN_SPRG9, r5
 
 	/* Load some guest volatiles. */
 	PPC_LL	r3, VCPU_LR(r4)