#WHAT DOES VIRTUALBOX GUEST ADDITIONS DO INSTALL#

It does not provide information on mouse buttons, though, and that continues to go through the standard PS/2 (or USB) mouse devices. Mouse Integration provides mouse position information using an absolute coordinate system.

#define VBOX_VENDOR_ID 0x80EE #define VBOX_DEVICE_ID 0xCAFE #define VBOX_VMMDEV_VERSION 0x00010003 #define VBOX_REQUEST_HEADER_VERSION 0x10001 #define VBOX_REQUEST_GUEST_INFO 50 /* VBox Guest packet header */ struct vbox_header Mouse Integration We will use 1.03, the so-called 'Legacy Protocol', as it is slightly simpler. There are two protocols that current versions of VirtualBox support: 1.03 and 1.04. Pci_device_t pci_find (vendor ,device ) // Read a field from the given PCI device uint32_t pci_read_field (pci_device_t device, field, size ) Initializing the Deviceīefore we can do anything with the guest device, we need to tell it about ourselves. void outports (port, value ) // Return an object describing the requested PCI device, if found. void outportl (port, value ) // Write a 16-bit value to an MMIO port. void install_interrupt_handler (irq, int ( *irq_function ) ( void ) ) // Write a 32-bit value to an MMIO port.

#WHAT DOES VIRTUALBOX GUEST ADDITIONS DO INSTALL#

void * map_physical_page ( uint32_t physical ) // Install an interrupt request handler function. void * allocate_physical_page ( uint32_t * physical ) // Map a physical page into the virtual memory space. Allocate one page of memory, providing its physical address as an output and virtual address as a return value. Pseudo-code examples in the following sections will assume the availability of these functions adjust them to match your environment: This page contains some struct definitions which could alternatively be obtained from headers provided by VirtualBox, but those headers are rather heavy and assume they are being used alongside a robust set of system headers, so instead we will define these structs ourselves. Communication from the VM is primarily initiated by an IRQ on the PCI device's interrupt line, which should then be followed up by appropriate packet requests, one of which should be of a special 'Acknowledge Events' type. Receiving works the same way, as you must prepare a packet with a request type and provide its physical address after the MMIO port write finishes, the packet will be populated with the appropriate values if the request was successful.

The basic process for sending a message to the VM is to prepare a packet and then write its (physical) address to the MMIO port. The MMIO operations that read or populate packets are synchronous, so setting up one page to pass back and forth is feasible. These can be anywhere in physical memory, and are relatively short. The format for the latter is unimportant for the features described on this page - you need only know that the region can be interpreted as an array of 32-bit unsigned integers and offset 3 contains the IRQ mask.Ĭommunication between the guest and the host happens through packets in memory. BAR0 is the MMIO port and BAR1 is a memory region that contains some shared state for the device, such as a bit mask for what events the guest wishes to receive. The PCI device has the vendor ID 0x80EE, same as the VirtualBox implementation of the Bochs display adapter, and a device ID of 0xCAFE. A combination of memory-mapped packets, MMIO port writes, and IRQs allow the guest to communicate its feature support to the VM and for the VM to communicate events such as display changes and mouse movement. The Guest Additions package operates through a PCI/mmio device provided by the VM.

What does virtualbox guest additions do