KVM: PPC: Find HTAB ourselves

For KVM we need to find the location of the HTAB. We can either rely
on internal data structures of the kernel or ask the hardware.

Ben issued complaints about the internal data structure method, so
let's switch it to our own inquiry of the HTAB. Now we're fully
independend :-).

CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kernel/ppc_ksyms.c

@@ -178,11 +178,6 @@ EXPORT_SYMBOL(switch_mmu_context);
 extern long mol_trampoline;
 EXPORT_SYMBOL(mol_trampoline); /* For MOL */
 EXPORT_SYMBOL(flush_hash_pages); /* For MOL */
-
-extern struct hash_pte *Hash;
-extern unsigned long _SDR1;
-EXPORT_SYMBOL_GPL(Hash); /* For KVM */
-EXPORT_SYMBOL_GPL(_SDR1); /* For KVM */
 #ifdef CONFIG_SMP
 extern int mmu_hash_lock;
 EXPORT_SYMBOL(mmu_hash_lock); /* For MOL */

arch/powerpc/kvm/book3s_32_mmu_host.c

@@ -54,6 +54,9 @@
 #error Only 32 bit pages are supported for now
 #endif
 
+static ulong htab;
+static u32 htabmask;
+
 static void invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
 {
 	volatile u32 *pteg;
@@ -217,28 +220,24 @@ static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
 	return NULL;
 }
 
-extern struct hash_pte *Hash;
-extern unsigned long _SDR1;
-
 static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
 				bool primary)
 {
-	u32 page, hash, htabmask;
-	ulong pteg = (ulong)Hash;
+	u32 page, hash;
+	ulong pteg = htab;
 
 	page = (eaddr & ~ESID_MASK) >> 12;
 
 	hash = ((vsid ^ page) << 6);
 	if (!primary)
 		hash = ~hash;
 
-	htabmask = ((_SDR1 & 0x1FF) << 16) | 0xFFC0;
 	hash &= htabmask;
 
 	pteg |= hash;
 
-	dprintk_mmu("htab: %p | hash: %x | htabmask: %x | pteg: %lx\n",
-		Hash, hash, htabmask, pteg);
+	dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
+		htab, hash, htabmask, pteg);
 
 	return (u32*)pteg;
 }
@@ -453,6 +452,7 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
 	int err;
+	ulong sdr1;
 
 	err = __init_new_context();
 	if (err < 0)
@@ -474,5 +474,10 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 
 	vcpu3s->vsid_next = vcpu3s->vsid_first;
 
+	/* Remember where the HTAB is */
+	asm ( "mfsdr1 %0" : "=r"(sdr1) );
+	htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
+	htab = (ulong)__va(sdr1 & 0xffff0000);
+
 	return 0;
 }