Have a pointer to an allocated region inside struct kvm.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm-slotslock/arch/x86/kvm/mmu.c
===================================================================
--- kvm-slotslock.orig/arch/x86/kvm/mmu.c
+++ kvm-slotslock/arch/x86/kvm/mmu.c
@@ -768,13 +768,14 @@ static int kvm_handle_hva(struct kvm *kv
 {
 	int i, j;
 	int retval = 0;
+	struct kvm_memslots *slots = kvm->memslots;
 
 	/*
 	 * If mmap_sem isn't taken, we can look the memslots with only
 	 * the mmu_lock by skipping over the slots with userspace_addr == 0.
 	 */
-	for (i = 0; i < kvm->nmemslots; i++) {
-		struct kvm_memory_slot *memslot = &kvm->memslots[i];
+	for (i = 0; i < slots->nmemslots; i++) {
+		struct kvm_memory_slot *memslot = &slots->memslots[i];
 		unsigned long start = memslot->userspace_addr;
 		unsigned long end;
 
@@ -2969,8 +2970,8 @@ unsigned int kvm_mmu_calculate_mmu_pages
 	unsigned int nr_mmu_pages;
 	unsigned int  nr_pages = 0;
 
-	for (i = 0; i < kvm->nmemslots; i++)
-		nr_pages += kvm->memslots[i].npages;
+	for (i = 0; i < kvm->memslots->nmemslots; i++)
+		nr_pages += kvm->memslots->memslots[i].npages;
 
 	nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
 	nr_mmu_pages = max(nr_mmu_pages,
@@ -3243,7 +3244,7 @@ static int count_rmaps(struct kvm_vcpu *
 	int i, j, k;
 
 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
-		struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
+		struct kvm_memory_slot *m = &vcpu->kvm->memslots->memslots[i];
 		struct kvm_rmap_desc *d;
 
 		for (j = 0; j < m->npages; ++j) {
Index: kvm-slotslock/arch/x86/kvm/vmx.c
===================================================================
--- kvm-slotslock.orig/arch/x86/kvm/vmx.c
+++ kvm-slotslock/arch/x86/kvm/vmx.c
@@ -1465,8 +1465,8 @@ static void enter_pmode(struct kvm_vcpu 
 static gva_t rmode_tss_base(struct kvm *kvm)
 {
 	if (!kvm->arch.tss_addr) {
-		gfn_t base_gfn = kvm->memslots[0].base_gfn +
-				 kvm->memslots[0].npages - 3;
+		gfn_t base_gfn = kvm->memslots->memslots[0].base_gfn +
+				 kvm->memslots->memslots[0].npages - 3;
 		return base_gfn << PAGE_SHIFT;
 	}
 	return kvm->arch.tss_addr;
Index: kvm-slotslock/arch/x86/kvm/x86.c
===================================================================
--- kvm-slotslock.orig/arch/x86/kvm/x86.c
+++ kvm-slotslock/arch/x86/kvm/x86.c
@@ -2159,7 +2159,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kv
 		spin_lock(&kvm->mmu_lock);
 		kvm_mmu_slot_remove_write_access(kvm, log->slot);
 		spin_unlock(&kvm->mmu_lock);
-		memslot = &kvm->memslots[log->slot];
+		memslot = &kvm->memslots->memslots[log->slot];
 		n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
 		memset(memslot->dirty_bitmap, 0, n);
 	}
@@ -4845,7 +4845,7 @@ int kvm_arch_set_memory_region(struct kv
 				int user_alloc)
 {
 	int npages = mem->memory_size >> PAGE_SHIFT;
-	struct kvm_memory_slot *memslot = &kvm->memslots[mem->slot];
+	struct kvm_memory_slot *memslot = &kvm->memslots->memslots[mem->slot];
 
 	/*To keep backward compatibility with older userspace,
 	 *x86 needs to hanlde !user_alloc case.
Index: kvm-slotslock/include/linux/kvm_host.h
===================================================================
--- kvm-slotslock.orig/include/linux/kvm_host.h
+++ kvm-slotslock/include/linux/kvm_host.h
@@ -151,14 +151,18 @@ struct kvm_irq_routing_table {};
 
 #endif
 
+struct kvm_memslots {
+	int nmemslots;
+	struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS +
+					KVM_PRIVATE_MEM_SLOTS];
+};
+
 struct kvm {
 	spinlock_t mmu_lock;
 	spinlock_t requests_lock;
 	struct rw_semaphore slots_lock;
 	struct mm_struct *mm; /* userspace tied to this vm */
-	int nmemslots;
-	struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS +
-					KVM_PRIVATE_MEM_SLOTS];
+	struct kvm_memslots *memslots;
 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
 	u32 bsp_vcpu_id;
 	struct kvm_vcpu *bsp_vcpu;
@@ -482,7 +486,7 @@ static inline void kvm_guest_exit(void)
 
 static inline int memslot_id(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-	return slot - kvm->memslots;
+	return slot - kvm->memslots->memslots;
 }
 
 static inline gpa_t gfn_to_gpa(gfn_t gfn)
Index: kvm-slotslock/virt/kvm/iommu.c
===================================================================
--- kvm-slotslock.orig/virt/kvm/iommu.c
+++ kvm-slotslock/virt/kvm/iommu.c
@@ -76,10 +76,13 @@ unmap_pages:
 static int kvm_iommu_map_memslots(struct kvm *kvm)
 {
 	int i, r = 0;
+	struct kvm_memslots *slots;
 
-	for (i = 0; i < kvm->nmemslots; i++) {
-		r = kvm_iommu_map_pages(kvm, kvm->memslots[i].base_gfn,
-					kvm->memslots[i].npages);
+	slots = kvm->memslots;
+
+	for (i = 0; i < slots->nmemslots; i++) {
+		r = kvm_iommu_map_pages(kvm, slots->memslots[i].base_gfn,
+					slots->memslots[i].npages);
 		if (r)
 			break;
 	}
@@ -210,10 +213,13 @@ static void kvm_iommu_put_pages(struct k
 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 {
 	int i;
+	struct kvm_memslots *slots;
+
+	slots = kvm->memslots;
 
-	for (i = 0; i < kvm->nmemslots; i++) {
-		kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn,
-				    kvm->memslots[i].npages);
+	for (i = 0; i < slots->nmemslots; i++) {
+		kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn,
+				    slots->memslots[i].npages);
 	}
 
 	return 0;
Index: kvm-slotslock/virt/kvm/kvm_main.c
===================================================================
--- kvm-slotslock.orig/virt/kvm/kvm_main.c
+++ kvm-slotslock/virt/kvm/kvm_main.c
@@ -348,12 +348,16 @@ static struct kvm *kvm_create_vm(void)
 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 #endif
 
+	r = -ENOMEM;
+	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
+	if (!kvm->memslots)
+		goto out_err;
+
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-	if (!page) {
-		r = -ENOMEM;
+	if (!page)
 		goto out_err;
-	}
+
 	kvm->coalesced_mmio_ring =
 			(struct kvm_coalesced_mmio_ring *)page_address(page);
 #endif
@@ -394,6 +398,7 @@ out:
 out_err:
 	hardware_disable_all();
 out_err_nodisable:
+	kfree(kvm->memslots);
 	kfree(kvm);
 	return ERR_PTR(r);
 }
@@ -428,9 +433,12 @@ static void kvm_free_physmem_slot(struct
 void kvm_free_physmem(struct kvm *kvm)
 {
 	int i;
+	struct kvm_memslots *slots = kvm->memslots;
+
+	for (i = 0; i < slots->nmemslots; ++i)
+		kvm_free_physmem_slot(&slots->memslots[i], NULL);
 
-	for (i = 0; i < kvm->nmemslots; ++i)
-		kvm_free_physmem_slot(&kvm->memslots[i], NULL);
+	kfree(kvm->memslots);
 }
 
 static void kvm_destroy_vm(struct kvm *kvm)
@@ -514,7 +522,7 @@ int __kvm_set_memory_region(struct kvm *
 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 		goto out;
 
-	memslot = &kvm->memslots[mem->slot];
+	memslot = &kvm->memslots->memslots[mem->slot];
 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 	npages = mem->memory_size >> PAGE_SHIFT;
 
@@ -535,7 +543,7 @@ int __kvm_set_memory_region(struct kvm *
 	/* Check for overlaps */
 	r = -EEXIST;
 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
-		struct kvm_memory_slot *s = &kvm->memslots[i];
+		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
 
 		if (s == memslot || !s->npages)
 			continue;
@@ -637,8 +645,8 @@ skip_lpage:
 		kvm_arch_flush_shadow(kvm);
 
 	spin_lock(&kvm->mmu_lock);
-	if (mem->slot >= kvm->nmemslots)
-		kvm->nmemslots = mem->slot + 1;
+	if (mem->slot >= kvm->memslots->nmemslots)
+		kvm->memslots->nmemslots = mem->slot + 1;
 
 	*memslot = new;
 	spin_unlock(&kvm->mmu_lock);
@@ -708,7 +716,7 @@ int kvm_get_dirty_log(struct kvm *kvm,
 	if (log->slot >= KVM_MEMORY_SLOTS)
 		goto out;
 
-	memslot = &kvm->memslots[log->slot];
+	memslot = &kvm->memslots->memslots[log->slot];
 	r = -ENOENT;
 	if (!memslot->dirty_bitmap)
 		goto out;
@@ -762,9 +770,10 @@ EXPORT_SYMBOL_GPL(kvm_is_error_hva);
 struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn)
 {
 	int i;
+	struct kvm_memslots *slots = kvm->memslots;
 
-	for (i = 0; i < kvm->nmemslots; ++i) {
-		struct kvm_memory_slot *memslot = &kvm->memslots[i];
+	for (i = 0; i < slots->nmemslots; ++i) {
+		struct kvm_memory_slot *memslot = &slots->memslots[i];
 
 		if (gfn >= memslot->base_gfn
 		    && gfn < memslot->base_gfn + memslot->npages)
@@ -783,10 +792,11 @@ struct kvm_memory_slot *gfn_to_memslot(s
 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
 {
 	int i;
+	struct kvm_memslots *slots = kvm->memslots;
 
 	gfn = unalias_gfn(kvm, gfn);
 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
-		struct kvm_memory_slot *memslot = &kvm->memslots[i];
+		struct kvm_memory_slot *memslot = &slots->memslots[i];
 
 		if (gfn >= memslot->base_gfn
 		    && gfn < memslot->base_gfn + memslot->npages)