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>

arch/powerpc/kvm/book3s_rmhandlers.S

@@ -36,7 +36,6 @@
 #if defined(CONFIG_PPC_BOOK3S_64)
 
 #define LOAD_SHADOW_VCPU(reg)	GET_PACA(reg)					
-#define SHADOW_VCPU_OFF		PACA_KVM_SVCPU
 #define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
 #define FUNC(name) 		GLUE(.,name)
 
@@ -66,7 +65,6 @@ kvmppc_skip_Hinterrupt:
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
 
-#define SHADOW_VCPU_OFF		0
 #define MSR_NOIRQ		MSR_KERNEL
 #define FUNC(name)		name
 
@@ -96,14 +94,14 @@ kvmppc_trampoline_\intno:
 	b	kvmppc_resume_\intno		/* Get back original handler */
 
 1:	tophys(r13, r13)
-	stw	r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+	stw	r12, HSTATE_SCRATCH1(r13)
 	mfspr	r12, SPRN_SPRG_SCRATCH1
-	stw	r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
-	lbz	r12, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)
+	stw	r12, HSTATE_SCRATCH0(r13)
+	lbz	r12, HSTATE_IN_GUEST(r13)
 	cmpwi	r12, KVM_GUEST_MODE_NONE
 	bne	..kvmppc_handler_hasmagic_\intno
 	/* No KVM guest? Then jump back to the Linux handler! */
-	lwz	r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+	lwz	r12, HSTATE_SCRATCH1(r13)
 	b	2b
 
 	/* Now we know we're handling a KVM guest */
@@ -146,8 +144,8 @@ INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
  *
  * R12            = free
  * R13            = Shadow VCPU (PACA)
- * SVCPU.SCRATCH0 = guest R12
- * SVCPU.SCRATCH1 = guest CR
+ * HSTATE.SCRATCH0 = guest R12
+ * HSTATE.SCRATCH1 = guest CR
  * SPRG_SCRATCH0  = guest R13
  *
  */
@@ -159,9 +157,9 @@ kvmppc_handler_skip_ins:
 	mtsrr0	r12
 
 	/* Clean up all state */
-	lwz	r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)
+	lwz	r12, HSTATE_SCRATCH1(r13)
 	mtcr	r12
-	PPC_LL	r12, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
+	PPC_LL	r12, HSTATE_SCRATCH0(r13)
 	GET_SCRATCH0(r13)
 
 	/* And get back into the code */