Merge git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: lock slots_lock around device assignment
  KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context
  KVM: unmap pages from the iommu when slots are removed
  KVM: PMU emulation: GLOBAL_CTRL MSR should be enabled on reset

arch/x86/kvm/pmu.c

@@ -459,17 +459,17 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu)
 	pmu->available_event_types = ~entry->ebx & ((1ull << bitmap_len) - 1);
 
 	if (pmu->version == 1) {
-		pmu->global_ctrl = (1 << pmu->nr_arch_gp_counters) - 1;
-		return;
-	}
-
+		pmu->nr_arch_fixed_counters = 0;
+	} else {
 		pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f),
 				X86_PMC_MAX_FIXED);
 		pmu->counter_bitmask[KVM_PMC_FIXED] =
 			((u64)1 << ((entry->edx >> 5) & 0xff)) - 1;
-	pmu->global_ctrl_mask = ~(((1 << pmu->nr_arch_gp_counters) - 1)
-			| (((1ull << pmu->nr_arch_fixed_counters) - 1)
-				<< X86_PMC_IDX_FIXED));
+	}
+
+	pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
+		(((1ull << pmu->nr_arch_fixed_counters) - 1) << X86_PMC_IDX_FIXED);
+	pmu->global_ctrl_mask = ~pmu->global_ctrl;
 }
 
 void kvm_pmu_init(struct kvm_vcpu *vcpu)

arch/x86/kvm/vmx.c

@@ -2210,9 +2210,12 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
 		msr = find_msr_entry(vmx, msr_index);
 		if (msr) {
 			msr->data = data;
-			if (msr - vmx->guest_msrs < vmx->save_nmsrs)
+			if (msr - vmx->guest_msrs < vmx->save_nmsrs) {
+				preempt_disable();
 				kvm_set_shared_msr(msr->index, msr->data,
 						   msr->mask);
+				preempt_enable();
+			}
 			break;
 		}
 		ret = kvm_set_msr_common(vcpu, msr_index, data);

include/linux/kvm_host.h

@@ -596,6 +596,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
 
 #ifdef CONFIG_IOMMU_API
 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot);
+void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot);
 int kvm_iommu_map_guest(struct kvm *kvm);
 int kvm_iommu_unmap_guest(struct kvm *kvm);
 int kvm_assign_device(struct kvm *kvm,
@@ -609,6 +610,11 @@ static inline int kvm_iommu_map_pages(struct kvm *kvm,
 	return 0;
 }
 
+static inline void kvm_iommu_unmap_pages(struct kvm *kvm,
+					 struct kvm_memory_slot *slot)
+{
+}
+
 static inline int kvm_iommu_map_guest(struct kvm *kvm)
 {
 	return -ENODEV;

virt/kvm/iommu.c

@@ -240,9 +240,13 @@ int kvm_iommu_map_guest(struct kvm *kvm)
 		return -ENODEV;
 	}
 
+	mutex_lock(&kvm->slots_lock);
+
 	kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type);
-	if (!kvm->arch.iommu_domain)
-		return -ENOMEM;
+	if (!kvm->arch.iommu_domain) {
+		r = -ENOMEM;
+		goto out_unlock;
+	}
 
 	if (!allow_unsafe_assigned_interrupts &&
 	    !iommu_domain_has_cap(kvm->arch.iommu_domain,
@@ -253,17 +257,16 @@ int kvm_iommu_map_guest(struct kvm *kvm)
 		       " module option.\n", __func__);
 		iommu_domain_free(kvm->arch.iommu_domain);
 		kvm->arch.iommu_domain = NULL;
-		return -EPERM;
+		r = -EPERM;
+		goto out_unlock;
 	}
 
 	r = kvm_iommu_map_memslots(kvm);
 	if (r)
-		goto out_unmap;
-
-	return 0;
-
-out_unmap:
 		kvm_iommu_unmap_memslots(kvm);
+
+out_unlock:
+	mutex_unlock(&kvm->slots_lock);
 	return r;
 }
 
@@ -310,6 +313,11 @@ static void kvm_iommu_put_pages(struct kvm *kvm,
 	}
 }
 
+void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
+{
+	kvm_iommu_put_pages(kvm, slot->base_gfn, slot->npages);
+}
+
 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 {
 	int idx;
@@ -320,7 +328,7 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 	slots = kvm_memslots(kvm);
 
 	kvm_for_each_memslot(memslot, slots)
-		kvm_iommu_put_pages(kvm, memslot->base_gfn, memslot->npages);
+		kvm_iommu_unmap_pages(kvm, memslot);
 
 	srcu_read_unlock(&kvm->srcu, idx);
 
@@ -335,7 +343,11 @@ int kvm_iommu_unmap_guest(struct kvm *kvm)
 	if (!domain)
 		return 0;
 
+	mutex_lock(&kvm->slots_lock);
 	kvm_iommu_unmap_memslots(kvm);
+	kvm->arch.iommu_domain = NULL;
+	mutex_unlock(&kvm->slots_lock);
+
 	iommu_domain_free(domain);
 	return 0;
 }

virt/kvm/kvm_main.c

@@ -808,12 +808,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	if (r)
 		goto out_free;
 
-	/* map the pages in iommu page table */
+	/* map/unmap the pages in iommu page table */
 	if (npages) {
 		r = kvm_iommu_map_pages(kvm, &new);
 		if (r)
 			goto out_free;
-	}
+	} else
+		kvm_iommu_unmap_pages(kvm, &old);
 
 	r = -ENOMEM;
 	slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),