Amazon Technologies, Inc.

Arm Limited

International Business Machines Corporation

University of Michigan

Other

Ali Ghassan Saidi

Pascal R Tannhof

Kerry A Kravec

Jan M Slyfield

Adi Habusha

Tzachi Zidenberg

Andreas Hansson

Richard Roy Grisenthwaite

Clark Debs Jeffries

Stephan Diestelhorst

Ravinder Kumar Sabhikhi

Prakash Shyamlal Ramrakhyani

Itai Avron

Ofer Naaman

Thomas Friedrich Wenisch

Geoffrey Wyman Blake

Kshitij Sudan

Ohad Gdalyahu

Marc A Boulanger

C Marcel Kinard

Aasheesh Kolli

Anirruddha Nagendran Udipi

Ron Diamant

Nafea Bshara

Randy Renfu Huang

Andrew Christopher Rose

Roland Alexander Paterson-Jones

Peter Chen

Michael Filippo

Matthew Lucien Evans

Wendy Arnott Elsasser

Christopher Daniel Emmons

Aniruddha Nagendran Udipi

Robert Gwilym Dimond

Mitchell Bryan Hayenga

Andrew Joseph Rushing

Matthew Lee Helsley

Noam Efraim Bashari

Andrea Pellegrini

Leonid Koilis

An input/output (I/O) device can initiate data migration of a virtual machine (VM) instance from a source device to a target device. The data migration of the VM instance may include migrating the data for the VM instance and tag data associated with the data. The data for the VM instance and the tag data may be stored together in a source memory. A first read request from the I/O device can enable a memory controller in the source device to read the data for the VM instance and the tag data together, store the tag data in a tag data buffer, and transmit the data for the VM instance to the target device. A second read request from the I/O device can read the stored tag data from the tag data buffer and transmit to the target device. The target device can write the data for the VM instance together with the tag data in the target memory.

Data migration with metadata

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.

Limiting use of encryption keys in an integrated circuit device

Methods and integrated circuit devices for recording memory-side page activity 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. To determine the memory pages that should be moved between the faster memory devices and the slower memory devices, counters may be implemented to count transactions to the memory pages. The counter values may be periodically checked to identify memory pages that can be moved from faster memory devices to slower memory devices, and vice-versa.

Memory-side page activity recorder

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.

Direct injection of a virtual interrupt

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.

Memory data migration hardware

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.

Wait optimizer for recording an order of first entry into a wait mode by a virtual central processing unit

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.

Write operations to non-volatile memory

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.

Performance checkpointing

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.

Memory scanner to accelerate page classification

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.

Nested page tables

A cache memory and method of operating a cache memory are provided. The cache memory comprises cache storage that stores cache lines for a plurality of requesters and cache control circuitry that controls insertion of a cache line into the cache storage when a memory access request from one of the plurality of requesters misses in the cache memory. The cache memory further has cache occupancy estimation circuitry that holds a count of insertions of cache lines into the cache storage for each of the plurality of requesters over a defined period. The count of cache line insertions for each requester thus provides an estimation of the cache occupancy associated with each requester.

Cache storage for multiple requesters and usage estimation thereof

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.

Power reduction in processor pipeline by detecting zeros

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.

Eliding redundant copying for virtual machine migration

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.

Reducing copy operations for a virtual machine migration

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Austin, TX, United States of America

Ali Ghassan Saidi