KVM: PPC: Move kvm_vcpu_ioctl_[gs]et_one_reg down to platform-specific code

This moves the get/set_one_reg implementation down from powerpc.c into
booke.c, book3s_pr.c and book3s_hv.c.  This avoids #ifdefs in C code,
but more importantly, it fixes a bug on Book3s HV where we were
accessing beyond the end of the kvm_vcpu struct (via the to_book3s()
macro) and corrupting memory, causing random crashes and file corruption.

On Book3s HV we only accept setting the HIOR to zero, since the guest
runs in supervisor mode and its vectors are never offset from zero.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
[agraf update to apply on top of changed ONE_REG patches]
Signed-off-by: Avi Kivity <avi@redhat.com>

4 files changed, 78 insertions, 38 deletions

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index fdc804c83938..3580db8a2326 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -398,6 +398,42 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r = -EINVAL;
+
+	switch (reg->id) {
+	case KVM_REG_PPC_HIOR:
+		r = put_user(0, (u64 __user *)reg->addr);
+		break;
+	default:
+		break;
+	}
+
+	return r;
+}
+
+int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r = -EINVAL;
+
+	switch (reg->id) {
+	case KVM_REG_PPC_HIOR:
+	{
+		u64 hior;
+		/* Only allow this to be set to zero */
+		r = get_user(hior, (u64 __user *)reg->addr);
+		if (!r && (hior != 0))
+			r = -EINVAL;
+		break;
+	}
+	default:
+		break;
+	}
+
+	return r;
+}
+
 int kvmppc_core_check_processor_compat(void)
 {
 	if (cpu_has_feature(CPU_FTR_HVMODE))
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 00efda6dc0e2..ee222ec7c95c 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -874,6 +874,38 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r = -EINVAL;
+
+	switch (reg->id) {
+	case KVM_REG_PPC_HIOR:
+		r = put_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
+		break;
+	default:
+		break;
+	}
+
+	return r;
+}
+
+int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	int r = -EINVAL;
+
+	switch (reg->id) {
+	case KVM_REG_PPC_HIOR:
+		r = get_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
+		if (!r)
+			to_book3s(vcpu)->hior_explicit = true;
+		break;
+	default:
+		break;
+	}
+
+	return r;
+}
+
 int kvmppc_core_check_processor_compat(void)
 {
 	return 0;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 9e41f45d07ed..ee9e1ee9c858 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -887,6 +887,16 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	return kvmppc_core_set_sregs(vcpu, sregs);
 }
 
+int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	return -EINVAL;
+}
+
+int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
+{
+	return -EINVAL;
+}
+
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
 	return -ENOTSUPP;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 59852091b389..e23270779ff5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -647,44 +647,6 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	return r;
 }
 
-static int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
-				      struct kvm_one_reg *reg)
-{
-	int r = -EINVAL;
-
-	switch (reg->id) {
-#ifdef CONFIG_PPC_BOOK3S
-	case KVM_REG_PPC_HIOR:
-		r = put_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
-		break;
-#endif
-	default:
-		break;
-	}
-
-	return r;
-}
-
-static int kvm_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
-				      struct kvm_one_reg *reg)
-{
-	int r = -EINVAL;
-
-	switch (reg->id) {
-#ifdef CONFIG_PPC_BOOK3S
-	case KVM_ONE_REG_PPC_HIOR:
-		r = get_user(to_book3s(vcpu)->hior, (u64 __user *)reg->addr);
-		if (!r)
-			to_book3s(vcpu)->hior_explicit = true;
-		break;
-#endif
-	default:
-		break;
-	}
-
-	return r;
-}
-
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                     struct kvm_mp_state *mp_state)
 {