Device Virtualization

Overview

The Host Compute APIs allow applications to extend the Hyper-V platform with virtualization support for generic PCI devices. By leveraging these APIs, applications can create virtual machines and offer them virtual devices that are not natively supported by the Hyper-V platform, such as cameras or sensors. The host-side code that virtualizes the device is supplied by the application, and the application is in full control of the device behavior as observed from the guest.

The following section contains the definitions of the APIs for device virtualization in the HCS. The DLL exports a set of C-style Windows API functions, the functions return HRESULT error codes indicating the result of the function call.

Device Virtualization Operations

Function	Description
HdvCreateDeviceInstance	Creates a device instance in the current host.
HdvCreateGuestMemoryAperture	Creates a guest RAM aperture in the address space of the calling process.
HdvCreateSectionBackedMmioRange	Maps a section into device MMIO space, so that accesses to those addresses are backed by the section.
HdvDeliverGuestInterrupt	Delivers a message signaled interrupt (MSI) to the guest partition.
HdvDestroySectionBackedMmioRange	Unmaps a section previously mapped via HdvCreateSectionBackedMmioRange.
HdvDeviceType	Discriminator for the Emulated device type.
HdvInitializeDeviceHost	Initializes a device emulator host in the caller's process.
HdvInitializeDeviceHostForProxy	Initializes the device emulator host in the caller's process and associates it with the specified proxy.
HdvPciBarSelector	Discriminator for the BAR selection.
HdvPciDeviceGetDetails	Queries the PCI description of the emulated device.
HdvPciDeviceInitialize	Initializes the emulated device.
HdvPciDeviceInterface	Device emulation callbacks for PCI devices.
HdvPciDeviceSetConfiguration	Sets the configuration of the emulated device.
HdvPciDeviceStart	Notifies the emulated device that the virtual processors of the VM are about to start.
HdvPciDeviceStop	Notifies the emulated device that the virtual processors of the VM are about to stop.
HdvPciDeviceTeardown	Tears down the emulated device.
HdvPciInterfaceVersion	Discriminator for the PCI device version.
HdvPciPnpId	PnP ID definition for a virtual device.
HdvPciReadConfigSpace	Executes a read into the emulated device's PCI config space.
HdvPciReadInterceptedMemory	Executes an intercepted MMIO read for the emulated device.
HdvPciWriteConfigSpace	Executes a write into the emulated device's PCI config space.
HdvPciWriteInterceptedMemory	Executes an intercepted MMIO write for the emulated device.
HdvProxyDeviceHost	Register a device host from another process with the compute system.
HdvReadGuestMemory	Reads guest primary memory (RAM) contents into a buffer.
HdvRegisterDoorbell	Registers a guest address to trigger an event on writes. The value of the write will be discarded.
HdvTeardownDeviceHost	Tears down the device emulator host in the caller's process.
HdvUnregisterDoorbell	Unregisters a doorbell notification.
HdvWriteGuestMemory	Writes the contents of a specified buffer to guest primary memory (RAM).