Kernel: Add AnonymousVMObject constructor for a Vector of physical pages

This will be used later on by the AHCI code to create a Region
that spans over scattered DMA pages.

Kernel/VM/AnonymousVMObject.cpp

@@ -81,6 +81,11 @@ RefPtr<AnonymousVMObject> AnonymousVMObject::create_with_size(size_t size, Alloc
     return adopt(*new AnonymousVMObject(size, commit));
 }
 
+NonnullRefPtr<AnonymousVMObject> AnonymousVMObject::create_with_physical_pages(NonnullRefPtrVector<PhysicalPage> physical_pages)
+{
+    return adopt(*new AnonymousVMObject(physical_pages));
+}
+
 NonnullRefPtr<AnonymousVMObject> AnonymousVMObject::create_with_physical_page(PhysicalPage& page)
 {
     return adopt(*new AnonymousVMObject(page));
@@ -127,6 +132,15 @@ AnonymousVMObject::AnonymousVMObject(PhysicalPage& page)
     physical_pages()[0] = page;
 }
 
+AnonymousVMObject::AnonymousVMObject(NonnullRefPtrVector<PhysicalPage> physical_pages)
+    : VMObject()
+    , m_volatile_ranges_cache({ 0, page_count() })
+{
+    for (auto& page : physical_pages) {
+        m_physical_pages.append(page);
+    }
+}
+
 AnonymousVMObject::AnonymousVMObject(const AnonymousVMObject& other)
     : VMObject(other)
     , m_volatile_ranges_cache({ 0, page_count() }) // do *not* clone this

Kernel/VM/AnonymousVMObject.h

@@ -43,6 +43,7 @@ public:
     static RefPtr<AnonymousVMObject> create_with_size(size_t, AllocationStrategy);
     static RefPtr<AnonymousVMObject> create_for_physical_range(PhysicalAddress paddr, size_t size);
     static NonnullRefPtr<AnonymousVMObject> create_with_physical_page(PhysicalPage& page);
+    static NonnullRefPtr<AnonymousVMObject> create_with_physical_pages(NonnullRefPtrVector<PhysicalPage>);
     virtual RefPtr<VMObject> clone() override;
 
     RefPtr<PhysicalPage> allocate_committed_page(size_t);
@@ -119,6 +120,7 @@ private:
     explicit AnonymousVMObject(size_t, AllocationStrategy);
     explicit AnonymousVMObject(PhysicalAddress, size_t);
     explicit AnonymousVMObject(PhysicalPage&);
+    explicit AnonymousVMObject(NonnullRefPtrVector<PhysicalPage>);
     explicit AnonymousVMObject(const AnonymousVMObject&);
 
     virtual const char* class_name() const override { return "AnonymousVMObject"; }

Kernel/VM/VMObject.cpp

@@ -35,6 +35,11 @@ VMObject::VMObject(const VMObject& other)
     MM.register_vmobject(*this);
 }
 
+VMObject::VMObject()
+{
+    MM.register_vmobject(*this);
+}
+
 VMObject::VMObject(size_t size)
 {
     m_physical_pages.resize(ceil_div(size, static_cast<size_t>(PAGE_SIZE)));

Kernel/VM/VMObject.h

@@ -88,6 +88,7 @@ public:
     }
 
 protected:
+    VMObject();
     explicit VMObject(size_t);
     explicit VMObject(const VMObject&);