KVM fixes for v4.14-rc7

PPC fixes for potential host oops and hangs.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "PPC fixes for potential host oops and hangs"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Book3S HV: Add more barriers in XIVE load/unload code
  KVM: PPC: Book3S: Protect kvmppc_gpa_to_ua() with SRCU
  KVM: PPC: Book3S HV: POWER9 more doorbell fixes
  KVM: PPC: Fix oops when checking KVM_CAP_PPC_HTM

arch/powerpc/kvm/book3s_64_vio.c

@@ -478,28 +478,30 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 		return ret;
 
 	dir = iommu_tce_direction(tce);
+
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+
 	if ((dir != DMA_NONE) && kvmppc_gpa_to_ua(vcpu->kvm,
-			tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), &ua, NULL))
+			tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), &ua, NULL)) {
-		return H_PARAMETER;
+		ret = H_PARAMETER;
+		goto unlock_exit;
+	}
 
 	entry = ioba >> stt->page_shift;
 
 	list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {
-		if (dir == DMA_NONE) {
+		if (dir == DMA_NONE)
 			ret = kvmppc_tce_iommu_unmap(vcpu->kvm,
 					stit->tbl, entry);
-		} else {
+		else
-			idx = srcu_read_lock(&vcpu->kvm->srcu);
 			ret = kvmppc_tce_iommu_map(vcpu->kvm, stit->tbl,
 					entry, ua, dir);
-			srcu_read_unlock(&vcpu->kvm->srcu, idx);
-		}
 
 		if (ret == H_SUCCESS)
 			continue;
 
 		if (ret == H_TOO_HARD)
-			return ret;
+			goto unlock_exit;
 
 		WARN_ON_ONCE(1);
 		kvmppc_clear_tce(stit->tbl, entry);
@@ -507,7 +509,10 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
 
 	kvmppc_tce_put(stt, entry, tce);
 
-	return H_SUCCESS;
+unlock_exit:
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
 

arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -989,13 +989,14 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	beq	no_xive
 	ld	r11, VCPU_XIVE_SAVED_STATE(r4)
 	li	r9, TM_QW1_OS
-	stdcix	r11,r9,r10
 	eieio
+	stdcix	r11,r9,r10
 	lwz	r11, VCPU_XIVE_CAM_WORD(r4)
 	li	r9, TM_QW1_OS + TM_WORD2
 	stwcix	r11,r9,r10
 	li	r9, 1
 	stw	r9, VCPU_XIVE_PUSHED(r4)
+	eieio
 no_xive:
 #endif /* CONFIG_KVM_XICS */
 
@@ -1310,6 +1311,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	bne	3f
 BEGIN_FTR_SECTION
 	PPC_MSGSYNC
+	lwsync
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
@@ -1400,8 +1402,8 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	cmpldi	cr0, r10, 0
 	beq	1f
 	/* First load to pull the context, we ignore the value */
-	lwzx	r11, r7, r10
 	eieio
+	lwzx	r11, r7, r10
 	/* Second load to recover the context state (Words 0 and 1) */
 	ldx	r11, r6, r10
 	b	3f
@@ -1409,8 +1411,8 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	cmpldi	cr0, r10, 0
 	beq	1f
 	/* First load to pull the context, we ignore the value */
-	lwzcix	r11, r7, r10
 	eieio
+	lwzcix	r11, r7, r10
 	/* Second load to recover the context state (Words 0 and 1) */
 	ldcix	r11, r6, r10
 3:	std	r11, VCPU_XIVE_SAVED_STATE(r9)
@@ -1420,6 +1422,7 @@ guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	stw	r10, VCPU_XIVE_PUSHED(r9)
 	stb	r10, (VCPU_XIVE_SAVED_STATE+3)(r9)
 	stb	r0, (VCPU_XIVE_SAVED_STATE+4)(r9)
+	eieio
 1:
 #endif /* CONFIG_KVM_XICS */
 	/* Save more register state  */
@@ -2788,6 +2791,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	PPC_MSGCLR(6)
 	/* see if it's a host IPI */
 	li	r3, 1
+BEGIN_FTR_SECTION
+	PPC_MSGSYNC
+	lwsync
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	lbz	r0, HSTATE_HOST_IPI(r13)
 	cmpwi	r0, 0
 	bnelr

arch/powerpc/kvm/powerpc.c

@@ -644,8 +644,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 #endif
 	case KVM_CAP_PPC_HTM:
-		r = cpu_has_feature(CPU_FTR_TM_COMP) &&
+		r = cpu_has_feature(CPU_FTR_TM_COMP) && hv_enabled;
-		    is_kvmppc_hv_enabled(kvm);
 		break;
 	default:
 		r = 0;