Abstract: A method and apparatus is described herein for supporting direct memory accesses between peer I/O devices. It is determined whether a guest physical address (GPA) referenced by an access generated from an I/O device, is within a range of GPAs associated with local I/O devices based at least in part on a GPA base and a GPA window size. If the GPA is within the window, then the GPA is translated to an HPA based at least in part on a base HPA associated with a local device and then forwarded to that local device. However, if the GPA is not within the window, then the access is forwarded upstream.

Abstract: An embodiment of the present invention is a technique to enhance address translation performance. A register stores capability indicators to indicate capability supported by a circuit in a chipset for address translation of a guest physical address to a host physical address. A plurality of multi-level page tables is used for page walking in the address translation. Each of the page tables has page table entries. Each of the page table entries has at least an entry specifier corresponding to the capability indicated by the capability indicators.

Abstract: A method and apparatus is described herein for supporting direct memory accesses between peer I/O devices. It is determined whether a guest physical address (GPA) referenced by an access generated from an I/O device, is within a range of GPAs associated with local I/O devices based at least in part on a GPA base and a GPA window size. If the GPA is within the window, then the GPA is translated to an HPA based at least in part on a base HPA associated with a local device and then forwarded to that local device. However, if the GPA is not within the window, then the access is forwarded upstream.

Abstract: An apparatus is disclosed. The apparatus includes a remapping circuit to facilitate access of one or more I/O devices to a memory device for direct memory access (DMA) transactions. The remapping circuit of the apparatus includes a translation mechanism to perform memory address translations for I/O DMA transactions via address window-based translations.

Abstract: According to one embodiment, USB device virtualization can be improved by giving virtual machines (VMs) direct access to USB devices with a combined hardware and software solution. One aspect is directed to including providing a set of PCI configuration registers and operational registers for each VM, providing an interrupt request line for each VM, and using a new schedule traversal algorithm for multiple schedules, including a fairness algorithm that prevents starvation of any VM's bulk traffic.

Abstract: A apparatus is disclosed. The apparatus includes a remapping circuit to facilitate access of one or more I/O devices to a memory device for direct memory access (DMA) transactions. The remapping circuit includes a translation mechanism to perform memory address translations for I/O DMA transactions via address window-based translations.

Abstract: A method and apparatus is described herein for supporting direct memory accesses between peer I/O devices. It is determined whether a guest physical address (GPA) referenced by an access generated from an I/O device, is within a range of GPAs associated with local I/O devices based at least in part on a GPA base and a GPA window size. If the GPA is within the window, then the GPA is translated to an HPA based at least in part on a base HPA associated with a local device and then forwarded to that local device. However, if the GPA is not within the window, then the access is forwarded upstream.

Abstract: An embodiment of the present invention is a technique to enhance address translation performance. A register stores capability indicators to indicate capability supported by a circuit in a chipset for address translation of a guest physical address to a host physical address. A plurality of multi-level page tables is used for page walking in the address translation. Each of the page tables has page table entries. Each of the page table entries has at least an entry specifier corresponding to the capability indicated by the capability indicators.

Abstract: A processor including logic to execute an instruction to synchronize a mapping from a physical address of a guest of a virtualization based system (guest physical address) to a physical address of the host of the virtualization based system (host physical address), and stored in a translation lookaside buffer (TLB), with a corresponding mapping stored in an extended paging table (EPT) of the virtualization based system.

Abstract: An embodiment of the present invention is a technique to process faults in a direct memory access address translation. A register set stores global control or status information for fault processing of a fault generated by an input/output (I/O) transaction requested by an I/O device. An address translation structure translates a guest physical address to a host physical address. The guest physical address corresponds to the I/O transaction and is mapped to a domain. The address translation structure has at least an entry associated with the domain and domain-specific control information for the fault processing.

Abstract: A processor including logic to execute an instruction to synchronize a mapping from a physical address of a guest of a virtualization based system (guest physical address) to a physical address of the host of the virtualization based system (host physical address), and stored in a translation lookaside buffer (TLB), with a corresponding mapping stored in an extended paging table (EPT) of the virtualization based system.

Abstract: An embodiment of the present invention is a technique to provide cache support for direct memory access address translation. A cache structure stores cached entries used in address translation of a guest physical address to a host physical address. The guest physical address corresponds to a guest domain identified by a guest domain identifier in an input/output (I/O) transaction requested by an I/O device. A register stores an invalidating domain identifier identifying an invalidating domain and an indicator indicating invalidating an entry in the cached entries having a tag.

Abstract: A direct memory access (“DMA”) request specifies a target address within an input/output virtual address (“IOVA”) space. The DMA target is validated and data are transferred between the target identified by the IOVA and a second location. Chipsets and systems using embodiments of the invention are also described and claimed.

Abstract: Embodiments of apparatuses, methods, and systems for delivering an interrupt to a virtual processor are disclosed. In one embodiment, an apparatus includes an interface to receive an interrupt request, delivery logic, and exit logic. The delivery logic is to determine, based on an attribute of the interrupt request, whether the interrupt request is to be delivered to the virtual processor. The exit logic is to transfer control to a host if the delivery logic determines that the interrupt request is not to be delivered to the virtual processor.

Abstract: Embodiments of apparatuses, methods, and systems for guests to access memory mapped devices are disclosed. In one embodiment, an apparatus includes evaluation logic and exit logic. The evaluation logic is to determine, in response to an attempt of a guest to access a device using a memory address mapped to the device and based on an access type, whether the access is allowed. The exit logic is to transfer control to a host if the evaluation logic determines that the access is not allowed.

Abstract: Embodiments of an apparatus, method, and system for encoding direct cache access transactions based on a memory access data structure are disclosed. In one embodiment, an apparatus includes memory access logic and transaction logic. The memory access logic is to determine whether to allow a memory access based on a memory access data structure. The transaction logic is to assign direct cache access attributes to a transaction based on the memory access data structure.

Abstract: A discussion for improving USB device virtualization by giving virtual machines (VMs) direct access to USB devices with a combined hardware and software solution, including providing a set of PCI configuration registers and operational registers for each VM, providing an interrupt request line for each VM, and using a new schedule traversal algorithm for multiple schedules, including a fairness algorithm that prevents starvation of any VM's bulk traffic.

Abstract: A apparatus is disclosed. The apparatus includes a remapping circuit to facilitate access of one or more I/O devices to a memory device for direct memory access (DMA) transactions. The remapping circuit includes a translation mechanism to perform memory address translations for I/O DMA transactions via address window-based translations.

Abstract: A processor including a virtualization system of the processor with a memory virtualization support system to map a reference to guest-physical memory made by guest software executable on a virtual machine which in turn is executable on a host machine in which the processor is operable to a reference to host-physical memory of the host machine.

Abstract: A method and apparatus is described herein for supporting direct memory accesses between peer I/O devices. It is determined whether a guest physical address (GPA) referenced by an access generated from an I/O device, is within a range of GPAs associated with local I/O devices based at least in part on a GPA base and a GPA window size. If the GPA is within the window, then the GPA is translated to an HPA based at least in part on a base HPA associated with a local device and then forwarded to that local device. However, if the GPA is not within the window, then the access is forwarded upstream.