KVM: PPC: Book3S HV: Fix setting of storage key in H_ENTER

In handling a H_ENTER hypercall, the code in kvmppc_do_h_enter
clobbers the high-order two bits of the storage key, which is stored
in a split field in the second doubleword of the HPTE.  Any storage
key number above 7 hence fails to operate correctly.

This makes sure we preserve all the bits of the storage key.
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -104,6 +104,7 @@
 #define HPTE_R_C		ASM_CONST(0x0000000000000080)
 #define HPTE_R_R		ASM_CONST(0x0000000000000100)
 #define HPTE_R_KEY_LO		ASM_CONST(0x0000000000000e00)
+#define HPTE_R_KEY		(HPTE_R_KEY_LO | HPTE_R_KEY_HI)
 
 #define HPTE_V_1TB_SEG		ASM_CONST(0x4000000000000000)
 #define HPTE_V_VRMA_MASK	ASM_CONST(0x4001ffffff000000)

arch/powerpc/kvm/book3s_hv_rm_mmu.c

@@ -269,7 +269,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 	if (!realmode)
 		local_irq_restore(irq_flags);
 
-	ptel &= ~(HPTE_R_PP0 - psize);
+	ptel &= HPTE_R_KEY | HPTE_R_PP0 | (psize-1);
 	ptel |= pa;
 
 	if (pa)