An apparatus includes an extended capability register and an input/output (I/O) memory management circuitry. The I/O memory management circuitry is to receive, from an I/O device, an address translation request referencing a guest virtual address associated with a guest virtual address space of a virtual machine. The I/O memory management circuitry may translate the guest virtual address to a guest physical address associated with a guest physical address space of the virtual machine, and, responsive to determining that a value stored by the extended capability register indicates a restrict-translation-request-response (RTRR) mode, transmit, to the I/O device, a translation response having the guest physical address.

Systems, apparatuses, and methods for performing efficient translation lookaside buffer (TLB) invalidation operations for splintered pages are described. When a TLB receives an invalidation request for a specified translation context, and the invalidation request maps to an entry with a relatively large page size, the TLB does not know if there are multiple translation entries stored in the TLB for smaller splintered pages of the relatively large page. The TLB tracks whether or not splintered pages for each translation context have been installed. If a TLB invalidate (TLBI) request is received, and splintered pages have not been installed, no searches are needed for splintered pages. To refresh the sticky bits, whenever a full TLB search is performed, the TLB rescans for splintered pages for other translation contexts. If no splintered pages are found, the sticky bit can be cleared and the number of full TLBI searches is reduced.

An apparatus includes multiple processors including respective cache memories, the cache memories configured to cache cache-entries for use by the processors. At least a processor among the processors includes cache management logic that is configured to (i) receive, from one or more of the other processors, cache-invalidation commands that request invalidation of specified cache-entries in the cache memory of the processor (ii) mark the specified cache-entries as intended for invalidation but defer actual invalidation of the specified cache-entries, and (iii) upon detecting a synchronization event associated with the cache-invalidation commands, invalidate the cache-entries that were marked as intended for invalidation.

In one embodiment, an apparatus includes a processor comprising an address translation cache (ATC); a shared work queue (SWQ) associated with the ATC, and a port to couple to a host processor over a Peripheral Component Interconnect Express (PCIe)-based link. The apparatus also includes circuitry to receive address translation information from a memory management unit of the host processor that includes virtual memory address to physical memory address translations, store the address translation information in the ATC, receive an invalidation command from the host processor indicating an invalidation of address translation information stored in the ATC, modify the address translation information in the ATC based on the invalidation command, and store completion data in a memory location indicated by the invalidation command.

An arbiter gathers translation invalidation requests assigned to state machines of a lower-level cache into a set for joint handling in a processor core. The gathering includes selection of one of the set of gathered translation invalidation requests as an end-of-sequence (EOS) request. The arbiter issues to the processor core a sequence of the gathered translation invalidation requests terminating with the EOS request. Based on receipt of each of the gathered requests, the processor core invalidates any translation entries providing translation for the addresses specified by the translation invalidation requests and marks memory-referent requests dependent on the invalidated translation entries. Based on receipt of the EOS request and in response to all of the marked memory-referent requests draining from the processor core, the processor core issues a completion request to the lower-level cache indicating completion of servicing by the processor core of the set of gathered translation invalidation requests.

A translation lookaside buffer (TLB) receives mapping invalidation requests from one or more sources, such as one or more processing units of a processing system. The TLB includes one or more invalidation processing pipelines, wherein each processing pipeline includes multiple processing states arranged in a pipeline, so that a given stage executes its processing operations concurrent with other stages of the pipeline executing their processing operations.

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.

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.

A processing system selectively compresses cache lines at a cache or at a memory or encrypts cache lines at the memory based on evictions of entries mapping virtual-to-physical address translations from a translation lookaside buffer (TLB). Upon eviction of a TLB entry, the processing system identifies cache lines corresponding to the physical addresses of the evicted TLB entry and selectively compresses the cache lines to increase the effective storage capacity of the processing system or encrypts the cache lines to protect against vulnerabilities.

Techniques are disclosed relating to managing storage array invalidations. A computer system may comprise a processor core configured to operate in an idle state and operate in a run state in which the processor core executes instructions. The computer system may further comprise a power management circuit that is configured to receive, while the processor core is in the idle state, a set of invalidation requests directed to the processor core to invalidate a set of entries of a storage array of the processor core. The power management circuit may store invalidation information indicative of the set of invalidation requests. The power management circuit may determine that the processor core has received a request to transition to the run state. Prior to the processor core operating in the run state, the power management circuit may invalidate the set of entries of the storage array based on the invalidation information.