KVM: PPC: Use MSR_DR for external load_up

Book3S_32 requires MSR_DR to be disabled during load_up_xxx while on Book3S_64
it's supposed to be enabled. I misread the code and disabled it in both cases,
potentially breaking the PS3 which has a really small RMA.

This patch makes KVM work on the PS3 again.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kvm/book3s_rmhandlers.S

@@ -202,8 +202,25 @@ _GLOBAL(kvmppc_rmcall)
 
 #if defined(CONFIG_PPC_BOOK3S_32)
 #define STACK_LR	INT_FRAME_SIZE+4
+
+/* load_up_xxx have to run with MSR_DR=0 on Book3S_32 */
+#define MSR_EXT_START						\
+	PPC_STL	r20, _NIP(r1);					\
+	mfmsr	r20;						\
+	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
+	andc	r3,r20,r3;		/* Disable DR,EE */	\
+	mtmsr	r3;						\
+	sync
+
+#define MSR_EXT_END						\
+	mtmsr	r20;			/* Enable DR,EE */	\
+	sync;							\
+	PPC_LL	r20, _NIP(r1)
+
 #elif defined(CONFIG_PPC_BOOK3S_64)
 #define STACK_LR	_LINK
+#define MSR_EXT_START
+#define MSR_EXT_END
 #endif
 
 /*
@@ -215,19 +232,12 @@ _GLOBAL(kvmppc_load_up_ ## what);				\
 	PPC_STLU r1, -INT_FRAME_SIZE(r1);			\
 	mflr	r3;						\
 	PPC_STL	r3, STACK_LR(r1);				\
-	PPC_STL	r20, _NIP(r1);					\
+	MSR_EXT_START;						\
-	mfmsr	r20;						\
-	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
-	andc	r3,r20,r3;		/* Disable DR,EE */	\
-	mtmsr	r3;						\
-	sync;							\
 								\
 	bl	FUNC(load_up_ ## what);				\
 								\
-	mtmsr	r20;			/* Enable DR,EE */	\
+	MSR_EXT_END;						\
-	sync;							\
 	PPC_LL	r3, STACK_LR(r1);				\
-	PPC_LL	r20, _NIP(r1);					\
 	mtlr	r3;						\
 	addi	r1, r1, INT_FRAME_SIZE;				\
 	blr