Abstract: A processing system includes a processor core for processing instructions and a memory that stores a page table set including an extended page table having an extended page table entry storing extended page table attributes associated with a physical memory page. The system receives a virtual address and translates the virtual address to a physical address for the physical memory page. One or more extended page attributes associated with the physical memory page are retrieved from the extended page table entry based on the virtual address.

Abstract: Systems, apparatuses, and methods for implementing a hardware enforcement mechanism to enable platform-specific firmware visibility into an error state ahead of the operating system are disclosed. A system includes at least one or more processor cores, control logic, a plurality of registers, platform-specific firmware, and an operating system (OS). The control logic allows the platform-specific firmware to decide if and when the error state is visible to the OS. In some cases, the platform-specific firmware blocks the OS from accessing the error state. In other cases, the platform-specific firmware allows the OS to access the error state such as when the OS needs to unmap a page. The control logic enables the platform-specific firmware, rather than the OS, to make decisions about the replacement of faulty components in the system.

Abstract: A processing core of a plurality of processing cores is configured to execute a speculative region of code a single atomic memory transaction with respect one or more others of the plurality of processing cores. In response to determining an abort condition for issued one of the plurality of program instructions and in response to determining that the issued program instruction is not part of a mispredicted execution path, the processing core is configured to abort an attempt to execute the speculative region of code.

Abstract: Systems, apparatuses, and methods for implementing a hardware enforcement mechanism to enable platform-specific firmware visibility into an error state ahead of the operating system are disclosed. A system includes at least one or more processor cores, control logic, a plurality of registers, platform-specific firmware, and an operating system (OS). The control logic allows the platform-specific firmware to decide if and when the error state is visible to the OS. In some cases, the platform-specific firmware blocks the OS from accessing the error state. In other cases, the platform-specific firmware allows the OS to access the error state such as when the OS needs to unmap a page. The control logic enables the platform-specific firmware, rather than the OS, to make decisions about the replacement of faulty components in the system.

Abstract: The described embodiments include a computing device with two or more translation lookaside buffers (TLB). During operation, the computing device updates an entry in the TLB based on a virtual address to physical address translation and metadata from a page table entry that were acquired during a page table walk. The computing device then computes, based on a lease length expression, a lease length for the entry in the TLB. Next, the computing device sets, for the entry in the TLB, a lease value to the lease length, wherein the lease value represents a time until a lease for the entry in the TLB expires, wherein the entry in the TLB is invalid when the associated lease has expired. The computing device then uses the lease value to control operations that are allowed to be performed using information from the entry in the TLB.

Abstract: The described embodiments include a computing device with two or more translation lookaside buffers (TLB) that performs operations for handling entries in the TLBs. During operation, the computing device maintains lease values for entries in the TLBs, the lease values representing times until leases for the entries expire, wherein a given entry in the TLB is invalid when the associated lease has expired. The computing device uses the lease value to control operations that are allowed to be performed using information from the entries in the TLBs. In addition, the computing device maintains, in a page table, longest lease values for page table entries indicating when corresponding longest leases for entries in TLBs expire. The longest lease values are used to determine when and if a TLB shootdown is to be performed.

Abstract: A processing core of a plurality of processing cores is configured to execute a speculative region of code a single atomic memory transaction with respect one or more others of the plurality of processing cores. In response to determining an abort condition for issued one of the plurality of program instructions and in response to determining that the issued program instruction is not part of a mispredicted execution path, the processing core is configured to abort an attempt to execute the speculative region of code.

Abstract: A processing core of a plurality of processing cores is configured to execute a speculative region of code as a single atomic memory transaction with respect one or more others of the plurality of processing cores. In response to determining an abort condition for an issued one of the plurality of program instructions and in response to determining that the issued program instruction is not part of a mispredicted execution path, the processing core is configured to abort an attempt to execute the speculative region of code.

Abstract: The described embodiments include a computing device with two or more translation lookaside buffers (TLB) that performs operations for handling entries in the TLBs. During operation, the computing device maintains lease values for entries in the TLBs, the lease values representing times until leases for the entries expire, wherein a given entry in the TLB is invalid when the associated lease has expired. The computing device uses the lease value to control operations that are allowed to be performed using information from the entries in the TLBs. In addition, the computing device maintains, in a page table, longest lease values for page table entries indicating when corresponding longest leases for entries in TLBs expire. The longest lease values are used to determine when and if a TLB shootdown is to be performed.

Abstract: The described embodiments include a computing device with two or more translation lookaside buffers (TLB). During operation, the computing device updates an entry in the TLB based on a virtual address to physical address translation and metadata from a page table entry that were acquired during a page table walk. The computing device then computes, based on a lease length expression, a lease length for the entry in the TLB. Next, the computing device sets, for the entry in the TLB, a lease value to the lease length, wherein the lease value represents a time until a lease for the entry in the TLB expires, wherein the entry in the TLB is invalid when the associated lease has expired. The computing device then uses the lease value to control operations that are allowed to be performed using information from the entry in the TLB.

Abstract: A system and method for efficiently performing program instrumentation. A processor processes instructions stored in a memory. The processor allocates a memory region for the purpose of creating “random branches” in the computer code utilizing existing memory access instructions. When the processor processes a given instruction, the processor both accesses a first location in the memory region and may determine a condition is satisfied. In response, the processor generates an interrupt. The corresponding interrupt handler may transfer control flow from the computer program to instrumentation code. The condition may include a pointer storing an address pointing to locations within the memory region equals a given address after the point is updated. Alternatively, the condition may include an updated data value stored in a location pointed to by the given address equals a threshold value.

Abstract: A system and method for efficiently performing program instrumentation. A processor processes instructions stored in a memory. When the processor processes a given instruction of a given instruction type, the processor updates a corresponding performance counter. When the performance counter reaches a threshold, the processor generates an interrupt and compares a location of the given instruction with stored locations in a given list. If a match is not found, then the processor processes an instruction following the given instruction in the computer program without processing intermediate instrumentation code. If a match is found, then the processor processes instrumentation code. Regardless of whether or not the instrumentation code is processed, when control flow returns to the computer program, the corresponding performance counter is initialized with a random value.

Abstract: A system and method for executing a transaction in a transactional memory system is disclosed. The system includes a processor of a plurality of processors coupled to shared memory, wherein the processor is configured to execute a section of code, including a plurality of memory access operations to the shared memory, as an atomic transaction relative to the execution of the plurality of processors. According to embodiments, the processor is configured to determine whether the memory access operations include any of a set of disallowed instructions, wherein the set includes one or more instructions that operate differently in a virtualized computing environment than in a native computing environment. If any of the memory access operations are ones of the disallowed instructions, then the processor aborts the transaction.

Abstract: A method and apparatus for compiling software written to be executed on a microprocessor that supports at least one hardware transactional memory function is provided. A compiler that supports at least one software transactional memory function is adapted to include a runtime system that maps between the at least one software transactional memory function and the at least one hardware transactional memory instruction.

Abstract: A system and method for efficiently performing program instrumentation. A processor processes instructions stored in a memory. When the processor processes a given instruction of a given instruction type, the processor updates a corresponding performance counter. When the performance counter reaches a threshold, the processor generates an interrupt and compares a location of the given instruction with stored locations in a given list. If a match is not found, then the processor processes an instruction following the given instruction in the computer program without processing intermediate instrumentation code. If a match is found, then the processor processes instrumentation code. Regardless of whether or not the instrumentation code is processed, when control flow returns to the computer program, the corresponding performance counter is initialized with a random value.

Abstract: A system and method for efficiently performing program instrumentation. A processor processes instructions stored in a memory. The processor allocates a memory region for the purpose of creating “random branches” in the computer code utilizing existing memory access instructions. When the processor processes a given instruction, the processor both accesses a first location in the memory region and may determine a condition is satisfied. In response, the processor generates an interrupt. The corresponding interrupt handler may transfer control flow from the computer program to instrumentation code. The condition may include a pointer storing an address pointing to locations within the memory region equals a given address after the point is updated. Alternatively, the condition may include an updated data value stored in a location pointed to by the given address equals a threshold value.

Abstract: An apparatus and method is disclosed for a computer processor configured to access a memory shared by a plurality of processing cores and to execute a plurality of memory access operations in a transactional mode as a single atomic transaction and to suspend the transactional mode in response to determining an implicit suspend condition, such as a program control transfer. As part of executing the transaction, the processor marks data accessed by the speculative memory access operations as being speculative data. In response to determining a suspend condition (including by detecting a control transfer in an executing thread) the processor suspends the transactional mode of execution, which includes setting a suspend flag and suspending marking speculative data. If the processor later detects a resumption condition (e.g., a return control transfer corresponding to a return from the control transfer), the processor is configured to resume the marking of speculative data.

Abstract: A system and method are disclosed wherein a processor of a plurality of processors coupled to shared memory, is configured to initiate execution of a section of code according to a first transactional mode of the processor. The processor is configured to execute a plurality of protected memory access operations to the shared memory within the section of code as a single atomic transaction with respect to the plurality of processors. The processor is further configured to initiate, within the section of code, execution of a subsection of the section of code according to a second transactional mode of the processor, wherein the first and second transactional modes are each associated with respective recovery actions that the processor is configured to perform in response to detecting an abort condition.

Abstract: A system and method are disclosed for allowing protection of larger areas than memory lines by monitoring accessed and dirty bits in page tables. More specifically, in some embodiments, a second associative structure with a different granularity is provided to filter out a large percentage of false positives. By providing the associative structure with sufficient size, the structure exactly specifies a region in which conflicting cache lines lie. If entries within this region are evicted from the structure, enabling the tracking for the entire index filters out a substantial number of false positives (depending on a granularity and a number of indices present). In some embodiments, this associative structure is similar to a translation look aside buffer (TLB) with 4 k, 2M entries.

Abstract: A method and apparatus are disclosed for implementing early release of speculatively read data in a hardware transactional memory system. A processing core comprises a hardware transactional memory system configured to receive an early release indication for a specified word of a group of words in a read set of an active transaction. The early release indication comprises a request to remove the specified word from the read set. In response to the early release request, the processing core removes the group of words from the read set only after determining that no word in the group other than the specified word has been speculatively read during the active transaction.