KVM: PPC: Put segment registers in shared page

Now that the actual mtsr doesn't do anything anymore, we can move the sr
contents over to the shared page, so a guest can directly read and write
its sr contents from guest context.

Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_book3s.h

@@ -70,7 +70,6 @@ struct kvmppc_vcpu_book3s {
 		u64 vsid;
 	} slb_shadow[64];
 	u8 slb_shadow_max;
-	u32 sr[16];
 	struct kvmppc_bat ibat[8];
 	struct kvmppc_bat dbat[8];
 	u64 hid[6];

arch/powerpc/include/asm/kvm_para.h

@@ -38,6 +38,7 @@ struct kvm_vcpu_arch_shared {
 	__u64 msr;
 	__u32 dsisr;
 	__u32 int_pending;	/* Tells the guest if we have an interrupt */
+	__u32 sr[16];
 };
 
 #define KVM_SC_MAGIC_R0		0x4b564d21 /* "KVM!" */

arch/powerpc/kvm/book3s.c

@@ -1161,10 +1161,9 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 			sregs->u.s.ppc64.slb[i].slbv = vcpu3s->slb[i].origv;
 		}
 	} else {
-		for (i = 0; i < 16; i++) {
-			sregs->u.s.ppc32.sr[i] = vcpu3s->sr[i];
-			sregs->u.s.ppc32.sr[i] = vcpu3s->sr[i];
-		}
+		for (i = 0; i < 16; i++)
+			sregs->u.s.ppc32.sr[i] = vcpu->arch.shared->sr[i];
+
 		for (i = 0; i < 8; i++) {
 			sregs->u.s.ppc32.ibat[i] = vcpu3s->ibat[i].raw;
 			sregs->u.s.ppc32.dbat[i] = vcpu3s->dbat[i].raw;

arch/powerpc/kvm/book3s_32_mmu.c

@@ -88,9 +88,9 @@ static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
 static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 					     u64 *vsid);
 
-static u32 find_sr(struct kvmppc_vcpu_book3s *vcpu_book3s, gva_t eaddr)
+static u32 find_sr(struct kvm_vcpu *vcpu, gva_t eaddr)
 {
-	return vcpu_book3s->sr[(eaddr >> 28) & 0xf];
+	return vcpu->arch.shared->sr[(eaddr >> 28) & 0xf];
 }
 
 static u64 kvmppc_mmu_book3s_32_ea_to_vp(struct kvm_vcpu *vcpu, gva_t eaddr,
@@ -211,7 +211,7 @@ static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
 	int i;
 	int found = 0;
 
-	sre = find_sr(vcpu_book3s, eaddr);
+	sre = find_sr(vcpu, eaddr);
 
 	dprintk_pte("SR 0x%lx: vsid=0x%x, raw=0x%x\n", eaddr >> 28,
 		    sr_vsid(sre), sre);
@@ -335,13 +335,13 @@ static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 
 static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
 {
-	return to_book3s(vcpu)->sr[srnum];
+	return vcpu->arch.shared->sr[srnum];
 }
 
 static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
 					ulong value)
 {
-	to_book3s(vcpu)->sr[srnum] = value;
+	vcpu->arch.shared->sr[srnum] = value;
 	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
 }
 
@@ -358,7 +358,7 @@ static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 	u64 gvsid = esid;
 
 	if (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
-		sr = find_sr(to_book3s(vcpu), ea);
+		sr = find_sr(vcpu, ea);
 		if (sr_valid(sr))
 			gvsid = sr_vsid(sr);
 	}

arch/powerpc/kvm/powerpc.c

@@ -66,7 +66,7 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
 		vcpu->arch.magic_page_pa = param1;
 		vcpu->arch.magic_page_ea = param2;
 
-		r2 = 0;
+		r2 = KVM_MAGIC_FEAT_SR;
 
 		r = HC_EV_SUCCESS;
 		break;