A system on chip (SoC) coupled to a memory can perform a hot-remove operation in a computer system. In a hot-remove operation, software (e.g., operating system) and hardware (e.g., memory controller and interconnect circuitry) components migrate memory content from one region to another target region in the memory. A peripheral device can have direct memory access (DMA) to a page in the region of memory that is being hot-removed. The interconnect circuitry can migrate the page to the target region while maintaining the peripheral device's direct access to the memory. Interconnect circuitry uses hardware mirroring in response to a write command to a memory address in the region being hot-removed. With hardware mirroring, the data is stored in two locations; the first location is the memory address in the region being moved, and the second location is a memory address in the target region.

The invention provides a memory device including a memory array, an internal memory, and a processor. The memory array stores node mapping tables for access data in the memory array. The internal memory includes a cached mapping table area and has a root mapping table. The processor determines whether a first node mapping table of the node mapping tables is temporarily stored in the cached mapping table area according to the root mapping table. In response to the first node mapping table is temporarily stored in the cached mapping table area, the processor accesses data according to the first node mapping table in the cached mapping table area, marks the modified first node mapping table through an asynchronous index identifier, and writes back the modified first node mapping table from the cached mapping table area to the memory array.

Operating system deactivation of write protection for a storage block is provided absent quiescing of processors in a multi-processor computing environment. The process includes receiving an address translation protection exception interrupt resulting from an attempted write access by a processor to a storage block, and determining by the operating system whether write protection for the storage block is active. Based on write protection for the storage block not being active, the operating system issues an instruction to clear or modify translation lookaside buffer entries of the processor associated with the storage block, absent waiting for an action by another processor of multiple processors of the computing environment, to facilitate write access to the storage block proceeding at the processor.

Methods, systems, and devices for compressed logical-to-physical mapping for sequentially stored data are described. A memory device may use a hierarchical set of logical-to-physical mapping tables for mapping logical block address generated by a host device to physical addresses of the memory device. The memory device may determine whether all of the entries of a terminal logical-to-physical mapping table are consecutive physical addresses. In response to determining that all of the entries contain consecutive physical addresses, the memory device may store a starting physical address of the consecutive physical addresses as an entry in a higher-level table along with a flag indicating that the entry points directly to data in the memory device rather than pointing to a terminal logical-to-physical mapping table. The memory device may, for subsequent reads of data stored in one or more of the consecutive physical addresses, bypass the terminal table to read the data.

A hypervisor identifies a memory address associated with a device slot of a communication bus; determines that the device slot of the communication bus is not associated with any of one or more devices; generates a memory page for the memory address, wherein the memory page comprises a value that indicates that the memory address is not associated with any of the devices; maps, in a page table, a page table entry for the memory page to the memory address, wherein the page table entry indicates that the memory page is read only for a guest operating system (OS) of a virtual machine (VM); and causes the memory page to be provided to the guest OS of the VM in view of a read access of the memory address by the guest OS.

The disclosed computer-implemented method may include (1) receiving, at a storage device via a cache-coherent interconnect, a first request to access data at one or more host addresses of a coherent memory space of an external host processor, (2) updating, in response to the first request, one or more statistics associated with accessing the data at the one or more host addresses, (3) receiving, at the storage device via the cache-coherent interconnect, a second request to perform an operation associated with the one or more statistics, and (4) using the one or more statistics to perform the operation. Various other methods, systems, and computer-readable media are also disclosed.

Systems and methods for memory management for virtual machines. An example method may include receiving, by a host computing system, a memory access request initiated by a peripheral component interconnect (PCI) device, wherein the memory access request comprises a memory address and an address translation flag specifying an address space associated with the memory address; and responsive to determining that the address translation flag is set to a first value indicating a host address space, causing a host system input/output memory management unit (IOMMU) to pass-through the memory access request.

There is provided an apparatus for receiving a request from a master to access an input address. Coarse grain access circuitry stores and provides a reference to an area of an output address space in dependence on the input address. One or more fine grain access circuits, each store and provide a reference to a sub-area in the area of the output address space in dependence on the input address. The apparatus forwards the request from the coarse grain access circuitry to one of the one fine grain access circuits in dependence on the input address.

An apparatus and method for efficient process-based compartmentalization. For example, one embodiment of a processor comprises: execution circuitry to execute instructions and process data; memory management circuitry coupled to the execution circuitry, the memory management circuitry to manage access to a system memory by a plurality of related processes using one or more process-specific translation structures and one or more shared translation structures to be shared by the related processes; and one or more control registers to store a process-specific base address pointer associated with a first process of the plurality of related processes and to store a shared base address pointer to identify the shared translation structures; wherein the memory management circuitry is to use the process-specific base address pointer in combination with a first linear address provided by the first process to walk the process-specific translation structures to identify any permissions and/or physical address associated with the first linear address, wherein if permissions are identified, the memory management circuitry is to use the permissions in place of any permissions specified in the shared translation structures.

To increase the speed with which a Second Layer Address Table (SLAT) is traversed, memory having the same access permissions is contiguously arranged such that one or more hierarchical levels of the SLAT need not be referenced, thereby resulting in more efficient SLAT traversal. “Slabs” of memory are established whose memory range is sufficiently large that reference to a hierarchically lower level table can be skipped and a hierarchically higher level table's entries can directly identify relevant memory addresses. Such slabs are aligned to avoid smaller intermediate memory ranges. The loading of code or data into memory is performed based on a next available memory location within a slab having equivalent access permissions, or, if such a slab is not available, or if an existing slab does not have a sufficient quantity of available memory remaining, a new slab with the proper access permissions is established.