International Business Machines Corporation

Christian Borntraeger

Jonathan D Bradbury

Lisa Cranton Heller

Reinhard Theodor Buendgen

Fadi Y Busaba

Claudio Imbrenda

Dominik Dingel

Martin Schwidefsky

Heiko Carstens

Utz Bacher

Janosch Andreas Frank

Timothy John Slegel

Damian Leo Osisek

Matthias Klein

Elpida Tzortzatos

Bruce C Giamei

Ute Gaertner

Einar Lueck

Carsten Otte

Christine M Yost

Christian Jacobi

Anthony Saporito

Cedric Lichtenau

Martin Recktenwald

Jakob Christopher Lang

Ulrich Weigand

Viktor Mihajlovski

Eberhard Pasch

Torsten Hendel

Christian Ehrhardt

Deferred reclaiming of secure guest resources within a computing environment is provided, which includes initiating, by a host of the computing environment, removal of a secure guest from the computing environment, while leaving one or more resources of the secure guest to be reclaimed asynchronous to the removal of the secure guest. The deferring also includes reclaiming the one or more secure guest resources asynchronous to the removal of the secure guest, where the one or more secure guest resources are available for reuse as the one or more secure guest resources are reclaimed asynchronous to the removal of the secure guest.

Deferred reclaiming of secure guest resources

A computer-implemented method, computer system and a computer program product schedule a secure code segment on a processor core of a processing unit between threads, wherein the processing unit is executing a program code of operating instructions of a thread on the at least one processor core. The method comprises a first thread requesting exclusive secure execution of a secure code segment of the program code on the at least one processor core. The method also comprises checking the request based on a secure-operation parameter that controls a request for exclusive secure execution of a secure code segment. The method further comprises, if the secure-operation parameter is below a predefined threshold value, setting the at least one processor core to exclusive secure execution for the secure code segment and periodically resetting the secure-operation parameter. If the secure-operation parameter is not below the threshold, then the method switches to another thread.

Scheduling a secure code segment on a processor core of a processing unit

A virtual machine is dispatched and based on the dispatch, a determination is made as to whether a select area of memory expected to be accessible to the virtual machine and used in communication between the virtual machine and an operating system is accessible to the virtual machine. Based on determining that the select area of memory is inaccessible to the virtual machine, virtual machine execution is exited with a select interception code.

Inaccessible prefix pages during virtual machine execution

At least one request to store diagnostic state of a virtual machine is obtained. Based on obtaining the at least one request, a store of diagnostic state of the virtual machine is performed to provide stored diagnostic state of the virtual machine. The performing the store includes encrypting the diagnostic state of the virtual machine that is unencrypted and being stored to prevent a reading of the diagnostic state of the virtual machine by an untrusted entity prior to encrypting the diagnostic state of the virtual machine that is unencrypted and being stored.

Storing diagnostic state of secure virtual machines

An instruction is provided to perform a reset address translation protection operation when executed. Executing the instruction includes determining, by a processor, that an address translation protection bit in a specified translation table entry associated with a storage block is to be reset. Based on determining that the address translation protection bit is to be reset, executing the instruction includes resetting the address translation protection bit to deactivate write protection for the storage block. The resetting is absent waiting for an action by one or more other processors of the computing environment.

Reset dynamic address translation protection instruction

A method, a computer system, and a computer program product for cryptography are provided. A guest virtual server registers with a trusted hypervisor by using guest credentials. A guest wrapping key associated with the guest credentials is generated. A satellite virtual server instance that shares a master key with the virtual guest server is generated in the trusted hypervisor. A copy of the guest wrapping key is passed to the satellite virtual server instance. A random guest key is wrapped with the guest wrapping key, thereby producing a wrapped guest key. The wrapped guest key is rewrapped with the master key to form a protected guest key.

Generating hypervisor protected key for cryptography

Aspects include circuitry that includes a first global generation counter (GGC) that is increased upon decoding of a branch instruction and a second GGC that is increased upon a completion of the branch instruction. Upon a triggered rollback, the first GGC is reset. The circuitry also includes a generation tag memory associated with a register that receives loads during a side-channel attacks which is set to the first GGC upon a first load, and a determination unit to determine, for a second load from an address depending on the register of the first load, a generation tag value associated with the register of the second load as a function of the first GGC, the second GGC, and the generation tag value associated with the register of the first load. A wait queue is configured to block the second load, if the generation tag is larger than the second GGC.

Hardware mitigation for Spectre and meltdown-like attacks

According to one or more embodiments of the present invention, a computer implemented method includes receiving, at a secure interface control of a computer system, an access request for a data structure related to a secure entity in a secure domain of the computer system. The secure interface control can check for a virtual storage address associated with a location of the data structure. The secure interface control can request an address translation using a virtual address space of a non-secure entity of the computer system based on determining that the location of the data structure is associated with the virtual storage address. The secure interface control can access the data structure based on a result of the address translation.

Host virtual address space for secure interface control storage

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 storage block write protection absent quiescing of processors

An example computer-implemented method includes presenting, by a hardware control of a computing system, an exception to an untrusted entity when the untrusted entity accesses a secure page stored in a memory of the computing system, the exception preventing the untrusted entity from accessing the secure page. The method further includes, in response to the exception, issuing, by the untrusted entity, an export call routine. The method further includes executing, by a secure interface control of the computing system, the export call routine.

Program interruptions for page importing/exporting

Secure processing within a computing environment is provided by incrementally decrypting a secure operating system image, including receiving, for a page of the secure operating system image, a page address and a tweak value used during encryption of the page. Processing determines that the tweak value has not previously been used during decryption of another page of the secure operating system image, and decrypts memory page content at the page address using an image encryption key and the tweak value to facilitate obtaining a decrypted secure operating system image. Further, integrity of the secure operating system image is verified, and based on verifying integrity of the secure operating system image, execution of the decrypted secure operating system image is started.

Incremental decryption and integrity verification of a secure operating system image

A method is provided by a secure interface control of a computer that provides a partial instruction interpretation for an instruction which enables an interruption. The secure interface control fetches a program status word or a control register value from a secure guest storage. The secure interface control notifies an untrusted entity of guest interruption mask updates. The untrusted entity is executed on and in communication with hardware of the computer through the secure interface control to support operations of a secure entity executing on the untrusted entity. The secure interface control receives, from the untrusted entity, a request to present a highest priority, enabled guest interruption in response to the notifying of the guest interruption mask updates. The secure interface control moves interruption information into a guest prefix page and injecting the interruption in the secure entity when an injection of the interruption is determined to be valid.

Secure interface control high-level instruction interception for interruption enablement

According to one or more embodiments of the present invention, a computer implemented method includes computing a hash value of a page of memory of a computer system and comparing the hash value with a previously computed hash value of the page. A per-encryption value per page can be used in encrypting the page based on determining that the hash value matches the previously computed hash value. A modified value of the per-encryption value per page can be used in encrypting the page based on determining that the hash value mismatches the previously computed hash value.

Secure paging with page change detection

A method, a computer system, and a computer program product may provide a cryptographic key object to a guest virtual server for use in cryptographic operations. The guest virtual server may register with a hypervisor. The hypervisor may generate a guest wrapping key associated with guest credentials from the registering. The hypervisor may also generate a satellite virtual server instance. The guest virtual server and the satellite virtual server instance share a master key that cannot be accessed by the hypervisor or by any guest virtual server. The trusted hypervisor may pass a copy of the guest wrapping key to the satellite virtual server instance. A random guest key may be generated and may be wrapped with a guest wrapping key thereby producing a wrapped guest key. The hypervisor may convert the wrapped guest key to be a protected key that serves as the cryptographic key object.

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Stuttgart, Germany

Christian Borntraeger