Vmware, Inc.

Google Inc.

Tintri Inc.

Vyacheslav Vladimirovich Malyugin

Boris Weissman

Ganesh Venkitachalam

Min Xu

Jeffrey W Sheldon

Daniel J Scales

Keith Adams

Rohit Jain

Santhosh Rao

Alexander Klaiber

Shinye Shiu

Mark G Gritter

Luigi Semenzato

Pratap Subrahmanyam

Edward Kihyen Lee

Choon Ping Chng

Petr Vandrovec

Pratap Vikram Singh

Carl Alan Waldspurger

Michael Nelson

Sameer Nanda

Zubin D Dittia

Tal Garfinkel

Keith Robert Pflederer

James Eugene Chow

Allan Douglas Knies

Brandon W Salmon

Chih-Chung Chang

Raj Ashok Sudarsanam

Kieran J Harty

Rahul Jagdish Thakur

Dmitry Grinberg

Aaron Durbin

Hsiao-Heng Kelin Lee

Andrew Biggadike

System and method for providing fault tolerance in virtualized computer systems use a first guest and a second guest running on virtualization software to produce outputs, which are produced when a workload is executed on the first and second guests. An output of the second guest is compared with an output of the first guest to determine if there is an output match. If there is no output match, the first guest is paused and a resynchronization of the second guest is executed to restore a checkpointed state of the first guest on the second guest. After the resynchronization of the second guest, the paused first guest is caused to resume operation.

Virtual machine fault tolerance

In a computer system running at least a first virtual machine (VM) and a second VM on virtualization software, a computer implemented method for the second VM to provide quasi-lockstep fault tolerance for the first VM includes executing a workload on the first VM and the second VM that involves producing at least one externally visible output and comparing an externally visible output of the second VM with an externally visible output of the first VM to determine if there is an output match. In response to a determination that the externally visible output of the second VM does not match the externally visible output of the first VM, a resynchronization of the second VM is executed. The externally visible output of the first VM is kept from being output externally until completion of the resynchronization.

Systems, devices, and methods for managing fragmentation in hardware-assisted compression of data in physical computer memory which may result in reduced internal fragmentation. An example computer-implemented method comprises: providing, by a memory management program to compression hardware, a compression command including an address in physical computer memory of data to be compressed and a list of at least two available buffers for storing compressed data; using, by the compression hardware, the address included in the compression command to retrieve uncompressed data; compressing the uncompressed data; and selecting, by the compression hardware, from the list of at least two available buffers, at least two buffers for storing compressed data based on an amount of space that would remain if the compressed data were stored in the at least two buffers, wherein each of the at least two selected buffers differs in size from at least one other of the selected buffers.

Managing memory fragmentation in hardware-assisted data compression

The output of a non-deterministic instruction is handled during record and replay in a virtual machine. An output of a non-deterministic instruction is stored to a buffer during record mode and retrieved from a buffer during replay mode without exiting to the hypervisor. At least part of the contents of the buffer can be stored to a log when the buffer is full during record mode, and the buffer can be replenished from a log when the buffer is empty during replay mode.

Efficient recording and replaying of non-deterministic instructions in a virtual machine and CPU therefor

Provided are methods and systems for memory decompression using a hardware decompressor that minimizes or eliminates the involvement of software. Custom decompression hardware is added to the memory subsystem, where the decompression hardware handles read accesses caused by, for example, cache misses or requests from devices to compressed memory blocks, by reading a compressed block, decompressing it into an internal buffer, and returning the requested portion of the block. The custom hardware is designed to determine if the block is compressed, and determine the parameters of compression, by checking unused high bits of the physical address of the access. This allows compression to be implemented without additional metadata, because the necessary metadata can be stored in unused bits in the existing page table structures.

Transparent hardware-assisted memory decompression

Autonomous selection between multiple virtualization techniques implemented in a virtualization layer of a virtualized computer system. The virtual machine monitor implements multiple virtualization support processors that each provide for the comprehensive handling of potential virtualization exceptions. A virtual machine monitor resident virtualization selection control is operable to select between use of first and second virtualization support processors dependent on identifying a predetermined pattern of temporally local privilege dependent instructions within a portion of an instruction stream as encountered in the execution of a guest operating system.

Adaptive dynamic selection and application of multiple virtualization techniques

Provided are methods, systems, and apparatus for managing and controlling memory caches, in particular, system level caches outside of those closest to the CPU. The processes and representative hardware structures that implement the processes are designed to allow for detailed control over the behavior of such system level caches. Caching policies are developed based on policy identifiers, where a policy identifier corresponds to a collection of parameters that control the behavior of a set of cache management structures. For a given cache, one policy identifier is stored in each line of the cache.

Memory system architecture

The translation lookaside buffer (TLB) of a processor is kept in synchronization with a guest page table by use of an indicator referred to as a 'T' bit. The T bit of the NPT/EPT entries mapping the guest page table are set when a page walk is performed on the NPT/EPT. When modifications are made to pages mapped by NPT/EPT entries with their T bit set, changes to the TLB are made so that the TLB remains in synchronization with the guest page table. Accordingly, record/replay of virtual machines of virtualized computer systems may be performed reliably with no non-determinism introduced by stale TLBs that fall out of synchronization with the guest page table.

Synchronizing a translation lookaside buffer with page tables

In a computer system running at least a first virtual machine (VM) and a second VM on virtualization software, a computer implemented method for the second VM to provide quasi-lockstep fault tolerance for the first VM. The method includes enabling operations of the second VM to diverge from being in lockstep with operations with the first VM without resynchronizing the second VM with the first VM, if output of the second VM is not diverging from output of the first VM. The output of the second VM is compared with the output of the first VM to determine whether the output of the second VM has diverged from the output of the first VM. In response to a determination that the output of the second VM has diverged from the output of the first VM, a resynchronization of the second VM is executed.

Automatically aligning virtual blocks of partitions to blocks of underlying physical storage is disclosed. In some embodiments, a starting offset of a partition included in a logical container is detected. In some embodiments, a misalignment correction amount for a partition included in a logical container is detected. In some embodiments, a misalignment associated with a partition included in a logical container is corrected.

Automatically aligning virtual blocks to physical blocks

Growing community of inventors

Los Gatos, CA, United States of America

Vyacheslav Vladimirovich Malyugin