Index: kvm-requests/arch/x86/kvm/vmx.c
===================================================================
--- kvm-requests.orig/arch/x86/kvm/vmx.c
+++ kvm-requests/arch/x86/kvm/vmx.c
@@ -2169,7 +2169,7 @@ static int alloc_apic_access_page(struct
 	struct kvm_userspace_memory_region kvm_userspace_mem;
 	int r = 0;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	if (kvm->arch.apic_access_page)
 		goto out;
 	kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
@@ -2191,7 +2191,7 @@ static int alloc_identity_pagetable(stru
 	struct kvm_userspace_memory_region kvm_userspace_mem;
 	int r = 0;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	if (kvm->arch.ept_identity_pagetable)
 		goto out;
 	kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
Index: kvm-requests/arch/x86/kvm/x86.c
===================================================================
--- kvm-requests.orig/arch/x86/kvm/x86.c
+++ kvm-requests/arch/x86/kvm/x86.c
@@ -1926,7 +1926,7 @@ static int kvm_vm_ioctl_set_nr_mmu_pages
 	if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	spin_lock(&kvm->mmu_lock);
 
 	kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
@@ -1982,7 +1982,7 @@ static int kvm_vm_ioctl_set_memory_alias
 	    < alias->target_phys_addr)
 		goto out;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	spin_lock(&kvm->mmu_lock);
 
 	p = &kvm->arch.aliases[alias->slot];
@@ -2137,7 +2137,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kv
 	struct kvm_memory_slot *memslot;
 	int is_dirty = 0;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 
 	r = kvm_get_dirty_log(kvm, log, &is_dirty);
 	if (r)
@@ -2253,7 +2253,7 @@ long kvm_arch_vm_ioctl(struct file *filp
 				   sizeof(struct kvm_pit_config)))
 			goto out;
 	create_pit:
-		down_write(&kvm->slots_lock);
+		kvm_grab_global_lock(kvm);
 		r = -EEXIST;
 		if (kvm->arch.vpit)
 			goto create_pit_unlock;
@@ -3548,7 +3548,7 @@ static void inject_pending_event(struct 
 
 static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 {
-	int r;
+	int r, dropped_slots_lock = 0;
 	bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
 		vcpu->run->request_interrupt_window;
 
@@ -3616,7 +3616,10 @@ static int vcpu_enter_guest(struct kvm_v
 		kvm_lapic_sync_to_vapic(vcpu);
 	}
 
-	up_read(&vcpu->kvm->slots_lock);
+	if (unlikely(test_bit(KVM_VCPU_DROP_LOCK, &vcpu->vcpu_state))) {
+		dropped_slots_lock = 1;
+		up_read(&vcpu->kvm->slots_lock);
+	}
 
 	kvm_guest_enter();
 
@@ -3668,8 +3671,8 @@ static int vcpu_enter_guest(struct kvm_v
 
 	preempt_enable();
 
-	down_read(&vcpu->kvm->slots_lock);
-
+	if (dropped_slots_lock)
+		down_read(&vcpu->kvm->slots_lock);
 	/*
 	 * Profile KVM exit RIPs:
 	 */
Index: kvm-requests/include/linux/kvm_host.h
===================================================================
--- kvm-requests.orig/include/linux/kvm_host.h
+++ kvm-requests/include/linux/kvm_host.h
@@ -44,6 +44,7 @@
 
 #define KVM_VCPU_GUEST_MODE        0
 #define KVM_VCPU_KICKED            1
+#define KVM_VCPU_DROP_LOCK         2
 
 struct kvm;
 struct kvm_vcpu;
@@ -408,6 +409,7 @@ void kvm_unregister_irq_ack_notifier(str
 				   struct kvm_irq_ack_notifier *kian);
 int kvm_request_irq_source_id(struct kvm *kvm);
 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
+void kvm_grab_global_lock(struct kvm *kvm);
 
 /* For vcpu->arch.iommu_flags */
 #define KVM_IOMMU_CACHE_COHERENCY	0x1
Index: kvm-requests/virt/kvm/coalesced_mmio.c
===================================================================
--- kvm-requests.orig/virt/kvm/coalesced_mmio.c
+++ kvm-requests/virt/kvm/coalesced_mmio.c
@@ -117,7 +117,7 @@ int kvm_vm_ioctl_register_coalesced_mmio
 	if (dev == NULL)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
 		up_write(&kvm->slots_lock);
 		return -ENOBUFS;
@@ -140,7 +140,7 @@ int kvm_vm_ioctl_unregister_coalesced_mm
 	if (dev == NULL)
 		return -EINVAL;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 
 	i = dev->nb_zones;
 	while(i) {
Index: kvm-requests/virt/kvm/eventfd.c
===================================================================
--- kvm-requests.orig/virt/kvm/eventfd.c
+++ kvm-requests/virt/kvm/eventfd.c
@@ -498,7 +498,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, st
 	else
 		p->wildcard = true;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 
 	/* Verify that there isnt a match already */
 	if (ioeventfd_check_collision(kvm, p)) {
@@ -541,7 +541,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, 
 	if (IS_ERR(eventfd))
 		return PTR_ERR(eventfd);
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 
 	list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
 		bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
Index: kvm-requests/virt/kvm/kvm_main.c
===================================================================
--- kvm-requests.orig/virt/kvm/kvm_main.c
+++ kvm-requests/virt/kvm/kvm_main.c
@@ -787,6 +787,22 @@ void kvm_reload_remote_mmus(struct kvm *
 	kvm_vcpus_request(kvm, KVM_REQ_MMU_RELOAD);
 }
 
+void kvm_grab_global_lock(struct kvm *kvm)
+{
+	int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		set_bit(KVM_VCPU_DROP_LOCK, &vcpu->vcpu_state);
+		barrier();
+		kvm_vcpu_ipi(vcpu);
+	}
+	down_write(&kvm->slots_lock);
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		clear_bit(KVM_VCPU_DROP_LOCK, &vcpu->vcpu_state);
+}
+EXPORT_SYMBOL_GPL(kvm_grab_global_lock);
+
 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 {
 	struct page *page;
@@ -1286,7 +1302,7 @@ int kvm_set_memory_region(struct kvm *kv
 {
 	int r;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
 	up_write(&kvm->slots_lock);
 	return r;
@@ -2556,7 +2572,7 @@ int kvm_io_bus_register_dev(struct kvm *
 {
 	int ret;
 
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	ret = __kvm_io_bus_register_dev(bus, dev);
 	up_write(&kvm->slots_lock);
 
@@ -2579,7 +2595,7 @@ void kvm_io_bus_unregister_dev(struct kv
 			       struct kvm_io_bus *bus,
 			       struct kvm_io_device *dev)
 {
-	down_write(&kvm->slots_lock);
+	kvm_grab_global_lock(kvm);
 	__kvm_io_bus_unregister_dev(bus, dev);
 	up_write(&kvm->slots_lock);
 }
