KVM: PPC: Split host-state fields out of kvmppc_book3s_shadow_vcpu

There are several fields in struct kvmppc_book3s_shadow_vcpu that
temporarily store bits of host state while a guest is running,
rather than anything relating to the particular guest or vcpu.
This splits them out into a new kvmppc_host_state structure and
modifies the definitions in asm-offsets.c to suit.

On 32-bit, we have a kvmppc_host_state structure inside the
kvmppc_book3s_shadow_vcpu since the assembly code needs to be able
to get to them both with one pointer.  On 64-bit they are separate
fields in the PACA.  This means that on 64-bit we don't need to
copy the kvmppc_host_state in and out on vcpu load/unload, and
in future will mean that the book3s_hv code doesn't need a
shadow_vcpu struct in the PACA at all.  That does mean that we
have to be careful not to rely on any values persisting in the
hstate field of the paca across any point where we could block
or get preempted.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index 8c5e0e1..c54b0e3 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -29,8 +29,7 @@
 #define ULONG_SIZE 		8
 #define FUNC(name) 		GLUE(.,name)
 
-#define GET_SHADOW_VCPU(reg)    \
-        addi    reg, r13, PACA_KVM_SVCPU
+#define GET_SHADOW_VCPU_R13
 
 #define DISABLE_INTERRUPTS	\
 	mfmsr   r0;		\
@@ -43,8 +42,8 @@
 #define ULONG_SIZE              4
 #define FUNC(name)		name
 
-#define GET_SHADOW_VCPU(reg)    \
-        lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
+#define GET_SHADOW_VCPU_R13	\
+	lwz	r13, (THREAD + THREAD_KVM_SVCPU)(r2)
 
 #define DISABLE_INTERRUPTS	\
 	mfmsr   r0;		\
@@ -107,18 +106,12 @@
 	/* Load non-volatile guest state from the vcpu */
 	VCPU_LOAD_NVGPRS(r4)
 
-	GET_SHADOW_VCPU(r5)
-
-	/* Save R1/R2 in the PACA */
-	PPC_STL	r1, SVCPU_HOST_R1(r5)
-	PPC_STL	r2, SVCPU_HOST_R2(r5)
-
-	/* XXX swap in/out on load? */
-	PPC_LL	r3, VCPU_HIGHMEM_HANDLER(r4)
-	PPC_STL	r3, SVCPU_VMHANDLER(r5)
-
 kvm_start_lightweight:
 
+	GET_SHADOW_VCPU_R13
+	PPC_LL	r3, VCPU_HIGHMEM_HANDLER(r4)
+	PPC_STL	r3, HSTATE_VMHANDLER(r13)
+
 	PPC_LL	r10, VCPU_SHADOW_MSR(r4)	/* r10 = vcpu->arch.shadow_msr */
 
 	DISABLE_INTERRUPTS