KVM: x86: work on all available address spaces

This patch has no semantic change, but it prepares for the introduction
of a second address space for system management mode.

A new function x86_set_memory_region (and the "slots_lock taken"
counterpart __x86_set_memory_region) is introduced in order to
operate on all address spaces when adding or deleting private
memory slots.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1189,4 +1189,9 @@ int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
 void kvm_handle_pmu_event(struct kvm_vcpu *vcpu);
 void kvm_deliver_pmi(struct kvm_vcpu *vcpu);
 
+int __x86_set_memory_region(struct kvm *kvm,
+			    const struct kvm_userspace_memory_region *mem);
+int x86_set_memory_region(struct kvm *kvm,
+			  const struct kvm_userspace_memory_region *mem);
+
 #endif /* _ASM_X86_KVM_HOST_H */

arch/x86/kvm/mmu.c

@@ -1503,30 +1503,33 @@ static int kvm_handle_hva_range(struct kvm *kvm,
 	struct kvm_memory_slot *memslot;
 	struct slot_rmap_walk_iterator iterator;
 	int ret = 0;
+	int i;
 
-	slots = kvm_memslots(kvm);
-
-	kvm_for_each_memslot(memslot, slots) {
-		unsigned long hva_start, hva_end;
-		gfn_t gfn_start, gfn_end;
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		slots = __kvm_memslots(kvm, i);
+		kvm_for_each_memslot(memslot, slots) {
+			unsigned long hva_start, hva_end;
+			gfn_t gfn_start, gfn_end;
 
-		hva_start = max(start, memslot->userspace_addr);
-		hva_end = min(end, memslot->userspace_addr +
-					(memslot->npages << PAGE_SHIFT));
-		if (hva_start >= hva_end)
-			continue;
-		/*
-		 * {gfn(page) | page intersects with [hva_start, hva_end)} =
-		 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
-		 */
-		gfn_start = hva_to_gfn_memslot(hva_start, memslot);
-		gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
-
-		for_each_slot_rmap_range(memslot, PT_PAGE_TABLE_LEVEL,
-				PT_MAX_HUGEPAGE_LEVEL, gfn_start, gfn_end - 1,
-				&iterator)
-			ret |= handler(kvm, iterator.rmap, memslot,
-				       iterator.gfn, iterator.level, data);
+			hva_start = max(start, memslot->userspace_addr);
+			hva_end = min(end, memslot->userspace_addr +
+				      (memslot->npages << PAGE_SHIFT));
+			if (hva_start >= hva_end)
+				continue;
+			/*
+			 * {gfn(page) | page intersects with [hva_start, hva_end)} =
+			 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
+			 */
+			gfn_start = hva_to_gfn_memslot(hva_start, memslot);
+			gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
+
+			for_each_slot_rmap_range(memslot, PT_PAGE_TABLE_LEVEL,
+						 PT_MAX_HUGEPAGE_LEVEL,
+						 gfn_start, gfn_end - 1,
+						 &iterator)
+				ret |= handler(kvm, iterator.rmap, memslot,
+					       iterator.gfn, iterator.level, data);
+		}
 	}
 
 	return ret;
@@ -4536,21 +4539,23 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 {
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;
-
-	slots = kvm_memslots(kvm);
+	int i;
 
 	spin_lock(&kvm->mmu_lock);
-	kvm_for_each_memslot(memslot, slots) {
-		gfn_t start, end;
-
-		start = max(gfn_start, memslot->base_gfn);
-		end = min(gfn_end, memslot->base_gfn + memslot->npages);
-		if (start >= end)
-			continue;
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		slots = __kvm_memslots(kvm, i);
+		kvm_for_each_memslot(memslot, slots) {
+			gfn_t start, end;
+
+			start = max(gfn_start, memslot->base_gfn);
+			end = min(gfn_end, memslot->base_gfn + memslot->npages);
+			if (start >= end)
+				continue;
 
-		slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
-				PT_PAGE_TABLE_LEVEL, PT_MAX_HUGEPAGE_LEVEL,
-				start, end - 1, true);
+			slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
+						PT_PAGE_TABLE_LEVEL, PT_MAX_HUGEPAGE_LEVEL,
+						start, end - 1, true);
+		}
 	}
 
 	spin_unlock(&kvm->mmu_lock);
@@ -4907,15 +4912,18 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
 	unsigned int  nr_pages = 0;
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;
+	int i;
 
-	slots = kvm_memslots(kvm);
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		slots = __kvm_memslots(kvm, i);
 
-	kvm_for_each_memslot(memslot, slots)
-		nr_pages += memslot->npages;
+		kvm_for_each_memslot(memslot, slots)
+			nr_pages += memslot->npages;
+	}
 
 	nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
 	nr_mmu_pages = max(nr_mmu_pages,
-			(unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
+			   (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
 
 	return nr_mmu_pages;
 }

arch/x86/kvm/vmx.c

@@ -4115,7 +4115,7 @@ static int alloc_apic_access_page(struct kvm *kvm)
 	kvm_userspace_mem.flags = 0;
 	kvm_userspace_mem.guest_phys_addr = APIC_DEFAULT_PHYS_BASE;
 	kvm_userspace_mem.memory_size = PAGE_SIZE;
-	r = __kvm_set_memory_region(kvm, &kvm_userspace_mem);
+	r = __x86_set_memory_region(kvm, &kvm_userspace_mem);
 	if (r)
 		goto out;
 
@@ -4150,7 +4150,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
 	kvm_userspace_mem.guest_phys_addr =
 		kvm->arch.ept_identity_map_addr;
 	kvm_userspace_mem.memory_size = PAGE_SIZE;
-	r = __kvm_set_memory_region(kvm, &kvm_userspace_mem);
+	r = __x86_set_memory_region(kvm, &kvm_userspace_mem);
 
 	return r;
 }
@@ -4956,7 +4956,7 @@ static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
 		.flags = 0,
 	};
 
-	ret = kvm_set_memory_region(kvm, &tss_mem);
+	ret = x86_set_memory_region(kvm, &tss_mem);
 	if (ret)
 		return ret;
 	kvm->arch.tss_addr = addr;

arch/x86/kvm/x86.c

@@ -7963,6 +7963,40 @@ void kvm_arch_sync_events(struct kvm *kvm)
 	kvm_free_pit(kvm);
 }
 
+int __x86_set_memory_region(struct kvm *kvm,
+			    const struct kvm_userspace_memory_region *mem)
+{
+	int i, r;
+
+	/* Called with kvm->slots_lock held.  */
+	BUG_ON(mem->slot >= KVM_MEM_SLOTS_NUM);
+
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		struct kvm_userspace_memory_region m = *mem;
+
+		m.slot |= i << 16;
+		r = __kvm_set_memory_region(kvm, &m);
+		if (r < 0)
+			return r;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__x86_set_memory_region);
+
+int x86_set_memory_region(struct kvm *kvm,
+			  const struct kvm_userspace_memory_region *mem)
+{
+	int r;
+
+	mutex_lock(&kvm->slots_lock);
+	r = __x86_set_memory_region(kvm, mem);
+	mutex_unlock(&kvm->slots_lock);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(x86_set_memory_region);
+
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	if (current->mm == kvm->mm) {
@@ -7974,13 +8008,13 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		struct kvm_userspace_memory_region mem;
 		memset(&mem, 0, sizeof(mem));
 		mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
-		kvm_set_memory_region(kvm, &mem);
+		x86_set_memory_region(kvm, &mem);
 
 		mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
-		kvm_set_memory_region(kvm, &mem);
+		x86_set_memory_region(kvm, &mem);
 
 		mem.slot = TSS_PRIVATE_MEMSLOT;
-		kvm_set_memory_region(kvm, &mem);
+		x86_set_memory_region(kvm, &mem);
 	}
 	kvm_iommu_unmap_guest(kvm);
 	kfree(kvm->arch.vpic);