Abstract: A data guard circuit can be used to verify encryption of the data traffic on a bus between two integrated circuit (IC) devices. The data guard circuit can monitor the data traffic on the bus to analyze the data traffic based on a configuration. The analysis can be performed by sampling the data traffic, and a statistical data pattern can be identified in the sampled data traffic. The statistical data pattern can be compared with a threshold to determine whether the data traffic is encrypted. The data guard circuit can generate a notification if the data traffic is not encrypted as expected so that an appropriate action can be taken to protect the data.

Abstract: An interposer circuit is used between an interrupt controller and a processor core to facilitate direct injection of a virtual interrupt into a guest executing on the processor core, even though the interrupt controller does not support the direct injection. The interposer circuit can convert a command received from the interrupt controller for a physical interrupt into another command for a virtual interrupt to make the processor core believe that the processor core has received a virtual interrupt even though the interrupt controller is not able to provide the virtual interrupt. The virtual interrupt can be directly injected into the processor core without the intervention of a hypervisor executing on the processor core.

Abstract: A host device may include an interconnect, a host memory, and a set of processor cores. A processor core may execute a VM assigned to a cryptographic key and may send a request to access a physical address in the host memory toward the interconnect. An enforcer device may receive the request and extract a key identifier from the request. The enforcer device may determine whether to allow the request to access the physical address via the interconnect based on the key identifier and a list of allowed keys stored on the enforcer device. If the enforcer device determines to not allow the request to access, the enforcer device may modify the physical address and/or the key identifier of the request.

Abstract: An integrated circuit for offloading a page migration operation from a host processor is provided. The integrated circuit is configured to: receive, from the host processor, a request to perform the page migration operation from a first physical address to a second physical address; and based on the request, perform the page migration operation. The page migration operation comprises: performing a copy operation of data from the first physical address to the second physical address, and updating a page table entry based on the second physical address, to enable the host processor to access the data from the second physical address based on the updated page table entry.

Abstract: A wait optimizer circuit can be coupled to a processor to monitor an entry of a virtual CPU (vCPU) into a wait mode to acquire a ticket lock. The wait optimizer can introduce an amount of delay, while the vCPU is in the wait mode, with an assumption that the spinlock may be resolved before sending a wake up signal to the processor for rescheduling. The wait optimizer can also record a time stamp only for a first entry of the vCPU from a plurality of entries into the wait mode within a window of time. The time stamps for vCPUs contending for the same ticket lock can be used by a hypervisor executing on the processor for rescheduling the vCPUs.

Abstract: An apparatus for processing data and a method of data processing are provided. A processor core in the apparatus performs data processing operations in response to a sequence of instructions, including write operations which write data items to a non-volatile memory. A write-back cache stores local copies of the data items retrieved from the memory and written to the memory by the processor core. A storage unit is provided which stores indications of the write operations initiated by the processor core and the processor core is configured to respond to an end instruction by causing the local copies of data items which are the subject of the write operations by the processor core, and for which an indication is stored in the storage unit, to be cleaned from the write-back cache to the memory. The indications of the write operations stored in the storage unit are then cleared.

Abstract: Techniques for obtaining the performance of an integrated circuit design are disclosed. One such technique may retrieve, from a data store, a set of snapshots of a virtual machine of a host system taken during execution of a performance test. For each snapshot in the set of snapshots, the snapshot can be loaded onto a virtual machine running on an emulator that is emulating the integrated circuit design. The virtual machine can be executed for a reduced runtime, and the performances measured during execution of the snapshots can be used to derive the performance of the integrated circuit design.

Abstract: Methods and integrated circuit devices for accelerating memory page classification are provided. Memory systems typically have a combination of faster memory devices and slower memory devices. Frequently accessed memory pages (hot pages) should be maintained in the faster memory devices while less frequently accessed memory pages (cold pages) should be maintained in the slower memory devices. Classification of memory pages as hot or cold pages may be performed by an integrated circuit device that reads counter values that count transactions to corresponding memory pages. A distribution of counter values may be determined, and memory pages may be identified as hot or cold memory pages based on thresholds applied to the distribution.

Abstract: A translation buffer is provided in parallel to a translation lookaside buffer (TLB) to cache translations between intermediate physical addresses (IPAs) and pointers for entries in the TLB corresponding to the IPAs. The pointers can be used to identify and invalidate only certain entries in the TLB as compared to invalidating the whole TLB.

Abstract: An interposer circuit is used between an interrupt controller and a processor core to facilitate direct injection of a virtual interrupt into a guest executing on the processor core, even though the interrupt controller does not support the direct injection. The interposer circuit can convert a command received from the interrupt controller for a physical interrupt into another command for a virtual interrupt to make the processor core believe that the processor core has received a virtual interrupt even though the interrupt controller is not able to provide the virtual interrupt. The virtual interrupt can be directly injected into the processor core without the intervention of a hypervisor executing on the processor core.

Abstract: Techniques are described for power reduction in a computer processor based on detection of whether data destined for input to an arithmetic logic unit (ALU) has a particular value. The data is written to a register prior to performing an arithmetic or logical operation using the data as an operand. Depending on a timing of when the data is supplied to the register, the determination is made before or after the data is written to the register, and a memory associated with the register is updated with a result of the determination. Contents of the memory are used to make a decision whether to allow the ALU to perform the arithmetic or logical operation. The memory can be implemented as a non-architectural register.

Abstract: Systems and methods are provided to reduce the number of redundant copy operations performed as part of a live migration of a virtual machine executing a guest. While pre-copying for the live migration of the VM, the guest may continue to write to the pages. A hypervisor may clear the dirty pages and schedule the copy operations of the modified pages in a processing engine for copying to a target device. In one embodiment, before initiating the copy operation, the processing engine may check if the page has been modified again and omit the copy operation if the page has been modified again.

Abstract: Systems and methods are provided to reduce the number of redundant copy operations performed as part of a live migration of a virtual machine executing a guest. A hypervisor can queue the copy operations in a processing engine. While pre-copying for the live migration of the VM, the guest may continue to write to the pages. In one embodiment, the processing engine may clear a dirty page just before performing the copy operation of the modified page to a target device, thus extending the window of time to capture any future writes to that page.

Abstract: An apparatus and method are provided for handling write operations. The apparatus has a first processing device for executing a sequence of instructions, where the sequence comprises at least one instruction to activate a software protocol to establish an ownership right for writing data to a first memory region, and at least one write instruction executed following establishment of the ownership right, in order to perform one or more write operations to output write data for storage in at least one memory location within the first memory region. A writeback cache associated with the first processing device is used to store the write data output during the one or more write operations. Coherency circuitry is coupled to the writeback cache and to at least one further cache associated with at least one further processing device. The first processing device is responsive to a trigger event to initiate a clean operation in order to cause the write data to be written from the writeback cache to memory.

Abstract: A wait optimizer circuit can be coupled to a processor to monitor an entry of a virtual CPU (vCPU) into a wait mode to acquire a ticket lock. The wait optimizer can introduce an amount of delay, while the vCPU is in the wait mode, with an assumption that the spinlock may be resolved before sending a wake up signal to the processor for rescheduling. The wait optimizer can also record a time stamp only for a first entry of the vCPU from a plurality of entries into the wait mode within a window of time. The time stamps for vCPUs contending for the same ticket lock can be used by a hypervisor executing on the processor for rescheduling the vCPUs.

Abstract: A translation buffer is provided in parallel to a translation lookaside buffer (TLB) to cache translations between intermediate physical addresses (IPAs) and pointers for entries in the TLB corresponding to the IPAs. The pointers can be used to identify and invalidate only certain entries in the TLB as compared to invalidating the whole TLB.

Abstract: An apparatus and method are provided for handling write operations. The apparatus has a first processing device for executing a sequence of instructions, where the sequence comprises at least one instruction to activate a software protocol to establish an ownership right for writing data to a first memory region, and at least one write instruction executed following establishment of the ownership right, in order to perform one or more write operations to output write data for storage in at least one memory location within the first memory region. A writeback cache associated with the first processing device is used to store the write data output during the one or more write operations. Coherency circuitry is coupled to the writeback cache and to at least one further cache associated with at least one further processing device. The first processing device is responsive to a trigger event to initiate a clean operation in order to cause the write data to be written from the writeback cache to memory.

Abstract: A data processing system 4 includes a translation lookaside buffer 6 storing mapping data entries 10 indicative of virtual-to-physical address mappings for different regions of physical addresses. A hint generator 20 coupled to the translation lookaside buffer 6 generates hint data in dependence upon the storage of mapping data entries within the translation lookaside buffer 6. The hint generator 20 tracks the loading of mapping data entries and the eviction of mapping data entries from the translation lookaside buffer 6. The hint data is supplied to a memory controller 8 which controls how data corresponding to respective different regions of physical addresses is stored within a heterogeneous memory system, e.g. the power state of different portions of the memories storing different regions, which type of memory is used to store different regions.

Abstract: A data processing system 2 including non-volatile memory 22 manages the ordering of writes to the non-volatile memory and persist barrier instructions using a persist buffer storing persist buffer data. A write controller responds to the persist buffer data to prevent writing to the non-volatile memory for instructions following a given persist barrier instruction within a sequence of program instructions before the writes to the non-volatile memory which precede that given persist barrier instruction have at least been acknowledged as received by the memory system containing the non-volatile memory. In the case of a multi-core system, cache snooping mechanisms are used to pass persistency dependence data between cores such that strong persist atomicity may be tracked and managed between the cores.

Abstract: An apparatus for processing data and a method of data processing are provided. A processor core in the apparatus performs data processing operations in response to a sequence of instructions, including write operations which write data items to a non-volatile memory. A write-back cache stores local copies of the data items retrieved from the memory and written to the memory by the processor core. A storage unit is provided which stores indications of the write operations initiated by the processor core and the processor core is configured to respond to an end instruction by causing the local copies of data items which are the subject of the write operations by the processor core, and for which an indication is stored in the storage unit, to be cleaned from the write-back cache to the memory. The indications of the write operations stored in the storage unit are then cleared.