KVM: PPC: Move kvm->arch.slot_phys into memslot.arch

Now that we have an architecture-specific field in the kvm_memory_slot
structure, we can use it to store the array of page physical addresses
that we need for Book3S HV KVM on PPC970 processors.  This reduces the
size of struct kvm_arch for Book3S HV, and also reduces the size of
struct kvm_arch_memory_slot for other PPC KVM variants since the fields
in it are now only compiled in for Book3S HV.

This necessitates making the kvm_arch_create_memslot and
kvm_arch_free_memslot operations specific to each PPC KVM variant.
That in turn means that we now don't allocate the rmap arrays on
Book3S PR and Book E.

Since we now unpin pages and free the slot_phys array in
kvmppc_core_free_memslot, we no longer need to do it in
kvmppc_core_destroy_vm, since the generic code takes care to free
all the memslots when destroying a VM.

We now need the new memslot to be passed in to
kvmppc_core_prepare_memory_region, since we need to initialize its
arch.slot_phys member on Book3S HV.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/kvm_host.h

@@ -204,7 +204,7 @@ struct revmap_entry {
 };
 
 /*
- * We use the top bit of each memslot->rmap entry as a lock bit,
+ * We use the top bit of each memslot->arch.rmap entry as a lock bit,
  * and bit 32 as a present flag.  The bottom 32 bits are the
  * index in the guest HPT of a HPTE that points to the page.
  */
@@ -215,14 +215,17 @@ struct revmap_entry {
 #define KVMPPC_RMAP_PRESENT	0x100000000ul
 #define KVMPPC_RMAP_INDEX	0xfffffffful
 
-/* Low-order bits in kvm->arch.slot_phys[][] */
+/* Low-order bits in memslot->arch.slot_phys[] */
 #define KVMPPC_PAGE_ORDER_MASK	0x1f
 #define KVMPPC_PAGE_NO_CACHE	HPTE_R_I	/* 0x20 */
 #define KVMPPC_PAGE_WRITETHRU	HPTE_R_W	/* 0x40 */
 #define KVMPPC_GOT_PAGE		0x80
 
 struct kvm_arch_memory_slot {
+#ifdef CONFIG_KVM_BOOK3S_64_HV
 	unsigned long *rmap;
+	unsigned long *slot_phys;
+#endif /* CONFIG_KVM_BOOK3S_64_HV */
 };
 
 struct kvm_arch {
@@ -246,8 +249,6 @@ struct kvm_arch {
 	unsigned long hpt_npte;
 	unsigned long hpt_mask;
 	spinlock_t slot_phys_lock;
-	unsigned long *slot_phys[KVM_MEM_SLOTS_NUM];
-	int slot_npages[KVM_MEM_SLOTS_NUM];
 	unsigned short last_vcpu[NR_CPUS];
 	struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
 	struct kvmppc_linear_info *hpt_li;

arch/powerpc/include/asm/kvm_ppc.h

@@ -143,7 +143,12 @@ extern struct kvmppc_linear_info *kvm_alloc_hpt(void);
 extern void kvm_release_hpt(struct kvmppc_linear_info *li);
 extern int kvmppc_core_init_vm(struct kvm *kvm);
 extern void kvmppc_core_destroy_vm(struct kvm *kvm);
+extern void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
+				     struct kvm_memory_slot *dont);
+extern int kvmppc_core_create_memslot(struct kvm_memory_slot *slot,
+				      unsigned long npages);
 extern int kvmppc_core_prepare_memory_region(struct kvm *kvm,
+				struct kvm_memory_slot *memslot,
 				struct kvm_userspace_memory_region *mem);
 extern void kvmppc_core_commit_memory_region(struct kvm *kvm,
 				struct kvm_userspace_memory_region *mem);

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -261,7 +261,7 @@ static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
 
 /*
  * This is called to get a reference to a guest page if there isn't
- * one already in the kvm->arch.slot_phys[][] arrays.
+ * one already in the memslot->arch.slot_phys[] array.
  */
 static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
 				  struct kvm_memory_slot *memslot,
@@ -276,7 +276,7 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
 	struct vm_area_struct *vma;
 	unsigned long pfn, i, npages;
 
-	physp = kvm->arch.slot_phys[memslot->id];
+	physp = memslot->arch.slot_phys;
 	if (!physp)
 		return -EINVAL;
 	if (physp[gfn - memslot->base_gfn])
@@ -1065,7 +1065,7 @@ void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
 		goto err;
 	if (!kvm->arch.using_mmu_notifiers) {
-		physp = kvm->arch.slot_phys[memslot->id];
+		physp = memslot->arch.slot_phys;
 		if (!physp)
 			goto err;
 		physp += gfn - memslot->base_gfn;

arch/powerpc/kvm/book3s_hv.c

@@ -1314,48 +1314,67 @@ static unsigned long slb_pgsize_encoding(unsigned long psize)
 	return senc;
 }
 
-int kvmppc_core_prepare_memory_region(struct kvm *kvm,
-				struct kvm_userspace_memory_region *mem)
+static void unpin_slot(struct kvm_memory_slot *memslot)
 {
-	unsigned long npages;
-	unsigned long *phys;
+	unsigned long *physp;
+	unsigned long j, npages, pfn;
+	struct page *page;
 
-	/* Allocate a slot_phys array */
-	phys = kvm->arch.slot_phys[mem->slot];
-	if (!kvm->arch.using_mmu_notifiers && !phys) {
-		npages = mem->memory_size >> PAGE_SHIFT;
-		phys = vzalloc(npages * sizeof(unsigned long));
-		if (!phys)
-			return -ENOMEM;
-		kvm->arch.slot_phys[mem->slot] = phys;
-		kvm->arch.slot_npages[mem->slot] = npages;
+	physp = memslot->arch.slot_phys;
+	npages = memslot->npages;
+	if (!physp)
+		return;
+	for (j = 0; j < npages; j++) {
+		if (!(physp[j] & KVMPPC_GOT_PAGE))
+			continue;
+		pfn = physp[j] >> PAGE_SHIFT;
+		page = pfn_to_page(pfn);
+		SetPageDirty(page);
+		put_page(page);
+	}
+}
+
+void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
+			      struct kvm_memory_slot *dont)
+{
+	if (!dont || free->arch.rmap != dont->arch.rmap) {
+		vfree(free->arch.rmap);
+		free->arch.rmap = NULL;
 	}
+	if (!dont || free->arch.slot_phys != dont->arch.slot_phys) {
+		unpin_slot(free);
+		vfree(free->arch.slot_phys);
+		free->arch.slot_phys = NULL;
+	}
+}
+
+int kvmppc_core_create_memslot(struct kvm_memory_slot *slot,
+			       unsigned long npages)
+{
+	slot->arch.rmap = vzalloc(npages * sizeof(*slot->arch.rmap));
+	if (!slot->arch.rmap)
+		return -ENOMEM;
+	slot->arch.slot_phys = NULL;
 
 	return 0;
 }
 
-static void unpin_slot(struct kvm *kvm, int slot_id)
+int kvmppc_core_prepare_memory_region(struct kvm *kvm,
+				      struct kvm_memory_slot *memslot,
+				      struct kvm_userspace_memory_region *mem)
 {
-	unsigned long *physp;
-	unsigned long j, npages, pfn;
-	struct page *page;
+	unsigned long *phys;
 
-	physp = kvm->arch.slot_phys[slot_id];
-	npages = kvm->arch.slot_npages[slot_id];
-	if (physp) {
-		spin_lock(&kvm->arch.slot_phys_lock);
-		for (j = 0; j < npages; j++) {
-			if (!(physp[j] & KVMPPC_GOT_PAGE))
-				continue;
-			pfn = physp[j] >> PAGE_SHIFT;
-			page = pfn_to_page(pfn);
-			SetPageDirty(page);
-			put_page(page);
-		}
-		kvm->arch.slot_phys[slot_id] = NULL;
-		spin_unlock(&kvm->arch.slot_phys_lock);
-		vfree(physp);
+	/* Allocate a slot_phys array if needed */
+	phys = memslot->arch.slot_phys;
+	if (!kvm->arch.using_mmu_notifiers && !phys && memslot->npages) {
+		phys = vzalloc(memslot->npages * sizeof(unsigned long));
+		if (!phys)
+			return -ENOMEM;
+		memslot->arch.slot_phys = phys;
 	}
+
+	return 0;
 }
 
 void kvmppc_core_commit_memory_region(struct kvm *kvm,
@@ -1482,11 +1501,16 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 		/* Initialize phys addrs of pages in RMO */
 		npages = ri->npages;
 		porder = __ilog2(npages);
-		physp = kvm->arch.slot_phys[memslot->id];
-		spin_lock(&kvm->arch.slot_phys_lock);
-		for (i = 0; i < npages; ++i)
-			physp[i] = ((ri->base_pfn + i) << PAGE_SHIFT) + porder;
-		spin_unlock(&kvm->arch.slot_phys_lock);
+		physp = memslot->arch.slot_phys;
+		if (physp) {
+			if (npages > memslot->npages)
+				npages = memslot->npages;
+			spin_lock(&kvm->arch.slot_phys_lock);
+			for (i = 0; i < npages; ++i)
+				physp[i] = ((ri->base_pfn + i) << PAGE_SHIFT) +
+					porder;
+			spin_unlock(&kvm->arch.slot_phys_lock);
+		}
 	}
 
 	/* Order updates to kvm->arch.lpcr etc. vs. rma_setup_done */
@@ -1547,12 +1571,6 @@ int kvmppc_core_init_vm(struct kvm *kvm)
 
 void kvmppc_core_destroy_vm(struct kvm *kvm)
 {
-	unsigned long i;
-
-	if (!kvm->arch.using_mmu_notifiers)
-		for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
-			unpin_slot(kvm, i);
-
 	if (kvm->arch.rma) {
 		kvm_release_rma(kvm->arch.rma);
 		kvm->arch.rma = NULL;

arch/powerpc/kvm/book3s_hv_rm_mmu.c

@@ -183,7 +183,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
 	rmap = &memslot->arch.rmap[slot_fn];
 
 	if (!kvm->arch.using_mmu_notifiers) {
-		physp = kvm->arch.slot_phys[memslot->id];
+		physp = memslot->arch.slot_phys;
 		if (!physp)
 			return H_PARAMETER;
 		physp += slot_fn;

arch/powerpc/kvm/book3s_pr.c

@@ -1220,7 +1220,19 @@ int kvm_vm_ioctl_get_smmu_info(struct kvm *kvm, struct kvm_ppc_smmu_info *info)
 }
 #endif /* CONFIG_PPC64 */
 
+void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
+			      struct kvm_memory_slot *dont)
+{
+}
+
+int kvmppc_core_create_memslot(struct kvm_memory_slot *slot,
+			       unsigned long npages)
+{
+	return 0;
+}
+
 int kvmppc_core_prepare_memory_region(struct kvm *kvm,
+				      struct kvm_memory_slot *memslot,
 				      struct kvm_userspace_memory_region *mem)
 {
 	return 0;

arch/powerpc/kvm/booke.c

@@ -1438,7 +1438,19 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 	return -ENOTSUPP;
 }
 
+void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
+			      struct kvm_memory_slot *dont)
+{
+}
+
+int kvmppc_core_create_memslot(struct kvm_memory_slot *slot,
+			       unsigned long npages)
+{
+	return 0;
+}
+
 int kvmppc_core_prepare_memory_region(struct kvm *kvm,
+				      struct kvm_memory_slot *memslot,
 				      struct kvm_userspace_memory_region *mem)
 {
 	return 0;

arch/powerpc/kvm/powerpc.c

@@ -389,19 +389,12 @@ long kvm_arch_dev_ioctl(struct file *filp,
 void kvm_arch_free_memslot(struct kvm_memory_slot *free,
 			   struct kvm_memory_slot *dont)
 {
-	if (!dont || free->arch.rmap != dont->arch.rmap) {
-		vfree(free->arch.rmap);
-		free->arch.rmap = NULL;
-	}
+	kvmppc_core_free_memslot(free, dont);
 }
 
 int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
 {
-	slot->arch.rmap = vzalloc(npages * sizeof(*slot->arch.rmap));
-	if (!slot->arch.rmap)
-		return -ENOMEM;
-
-	return 0;
+	return kvmppc_core_create_memslot(slot, npages);
 }
 
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
@@ -410,7 +403,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                    struct kvm_userspace_memory_region *mem,
                                    int user_alloc)
 {
-	return kvmppc_core_prepare_memory_region(kvm, mem);
+	return kvmppc_core_prepare_memory_region(kvm, memslot, mem);
 }
 
 void kvm_arch_commit_memory_region(struct kvm *kvm,