摘要:
Virtual-machine-monitor operation and implementation is facilitated by number of easily implemented features and extensions added to the features of a processor architecture. These features, one or more of which are used in various embodiments of the present invention, include a vmsw instruction that provides a means for transitioning between virtualization mode and non-virtualization mode without an interruption, a virtualization fault that faults on an attempt by a priority-0 routine in virtualization mode attempting to execute a privileged instruction, and a flexible highest-implemented-address mechanism to partition virtual address space into a virtualization address space and a non-virtualization address space.
摘要:
The present invention provides a multiprocessor system and method in which plural memory locations are used for storing TLB-shootdown data respectively for plural processors. In contrast to systems in which a single area of memory serves for all processors' TLB-shootdown data, different processors can describe the memory they want to free concurrently. Thus, concurrent TLB-shootdown request are less likely to result in performance-limiting TLB-shootdown contentions that have previously constrained the scaleability of multiprocessor systems.
摘要:
A method and system for determining, at run-time, whether or not to defer an exception that arises during execution of a control-speculative load instruction based on a recent history of execution of that control-speculative load instruction. The method and system relies on recent execution history stored in a speculative-load-accelerated-deferral table. If an exception arises during execution of a control-speculative load instruction, then the speculative-load-accelerated-deferral table is searched for an entry corresponding to the control-speculative load instruction. If an entry is found, then the exception is deferred, since the speculative-load-accelerated-deferral table indicates that a recent exception arising from execution of the control-speculative load instruction was not recovered via a chk.s-mediated branch to a recovery block, and not otherwise used by a non-speculative instruction. By contrast, if no entry corresponding to the control-speculative load instruction is found in the speculative-load-accelerated-deferral table, then the exception is immediately handled.
摘要:
Method and apparatus for managing access to registers that are outside a current register stack frame are disclosed. An instruction execution unit in a processor receives an instruction to be executed. A processor includes a register stack, the register stack including a plurality of register stack frames. Each of the register stack frames includes zero or more registers. One of the plurality of register stack frames is a current register stack frame. When execution of the instruction requires writing to a register referenced by the instruction, the instruction execution unit determines whether the register referenced by the instruction is within the current register stack frame. If the instruction execution unit determines that the register is not within the current register stack frame, the instruction execution unit does not execute the instruction and may, for example, generate a fault. The instruction execution unit executes the instruction is the instruction execution unit determines that the register is within the current register stack frame. When execution of the instruction requires reading from a register referenced by the instruction, the instruction execution unit executes the instruction whether or not the register referenced by the instruction is within the current register stack frame.
摘要:
A computer system comprises a physical computer and a virtual machine monitor executable on the physical computer and configured to create an emulation of at least one guest operating system adapted to control the physical computer. The computer system further comprises a host executable on the physical computer that manages physical resources coupled to the physical computer on behalf of the virtual machine monitor and the at least one guest operating system. The host is adapted to virtualize a Peripheral Component Interconnect (PCI) configuration address space whereby the at least one guest operating system controls PCI input/output (I/O) devices directly and in absence of I/O emulation.
摘要:
Method and apparatus for allowing a direct memory access unit to have access to a virtual address space is accomplished by receiving a request for memory access from the direct memory access device; determining a device identifier according to the received request for memory access; determining a memory protection schema according to the determined device identifier; and granting the direct memory access unit access to memory in accordance with the determined memory protection schema.
摘要:
One embodiment disclosed relates to a method of reducing access latency to a task priority register (TPR) of a local programmable interrupt controller unit within a microprocessor. A command is received to write an interrupt mask value to the TPR, and the interrupt mask value is written to the TPR. In addition, the interrupt mask value is also written into a shadow copy of the TPR. The shadow copy is written each time that the TPR is written. Another embodiment disclosed relates to a method of reducing a latency to read a TPR of an IPF type microprocessor. When a command is received to read an interrupt mask value from the TPR, the interrupt mask value is read from the shadow copy at a memory location, instead of from the task priority register itself.
摘要:
A computer-implemented method and apparatus for transferring the contents of a general register, in a register stack, to a location in a backing store in a main memory are described. When transferring the contents of a general register to a location in the backing store, the invention proposes collecting attribute bits included in each general register of a predetermined group of registers in a temporary collection register. Once the temporary collection register has been filled, the contents of this register are written to the next available location in the backing store. Similarly, on the restoration of registers from the backing store, a collection of attribute bits saved in the backing register is transferred to a temporary collection register. Thereafter, each attribute bit is saved together with associated data into a general register, thereby to restore the former contents of each general register.
摘要:
A computer implemented method for switching from an interrupted context to an interrupting context in a processor is provided. The processor includes a register stack (RS) that has first and second portions. The processor includes a register stack engine (RSE) that exchanges information, in one of instruction execution dependent and independent modes between the second portion and a storage area. The method includes the following steps: a state of the RSE of the interrupted context is preserved; a COVER instruction is issued; a first (BSPSTORE) pointer is preserved. The first pointer points to a location in the storage area, of the interrupted context, where a next register of the second portion is to be written; first pointer is written with a value corresponding to the interrupting context; and a second pointer (BSP) is preserved. The new first and second pointers in the interrupting context define the storage area of RS values associated with the interrupted context. The new first pointer is subtracted from the second new pointer. The difference (number of dirty registers) is deposited into the RSC.loadrs field. A LOADRS instruction is issued to load the RS with all interrupted context values. The original first BSPSTORE is restored from the preserved BSPSTORE.
摘要:
A method for mapping an active entry within a virtually hashed page table is disclosed. An active entry within a virtually hashed page table is populated. A link table for locating a link at an offset from an active entry is maintained. This link table continues to be maintained as a valid link table until an occupied head bucket threshold is exceeded or a collision has occurred.