A processor includes a processing core to identify a code comprising a plurality of instructions to be executed in the architecturally-protected environment, determine that a first physical memory page stored in the architecturally-protected memory matches a first virtual memory page referenced by a first instruction of the plurality of instructions, generate a first address mapping between a first address of the first virtual memory page and a second address of the first physical memory page, store, in the cache memory, the address translation data structure comprising the first address mapping, and execute the code by retrieving the first address mapping in the address translation data structures to be executed in the architecturally-protected environment, determine that a first physical memory page stored in the architecturally-protected memory matches a first virtual memory page referenced by a first instruction of the plurality of instructions, generate a first address mapping between a first address of the first virtual memory page and a second address of the first physical memory page, store, in the cache memory, an address translation data structure comprising the first address mapping, and execute the code by retrieving the first address mapping stored in the address translation data structure.

Mechanism to prevent software side channels

Technologies are disclosed herein for blocking access to some firmware variables during runtime. These firmware variables may be disallowed from runtime access (e.g., read/write access), by placing an indication of the firmware variables on a runtime blocklist. Upon completion of booting, runtime firmware services may access the runtime blocklist to determine if a firmware variable is to be accessed during runtime. In some cases, a firmware variable may be disallowed from runtime access by inclusion in the runtime blocklist, even if that firmware variable has an attribute that indicates that it is runtime accessible. The runtime blocklist may be generated based at least in part on indications of the firmware variables to be blocked during runtime. Additionally, runtime accessible firmware variables may be exposed to higher-level software, such as an O/S, if the firmware variables are not included in the runtime blocklist.

Blocking runtime firmware variable access

Approaches for securing a host machine against security attacks conducted using Direct Memory Access (DMA). Platform firmware does not enable bus mastering during PCI bus enumeration. When the platform firmware determines that an expansion card has been plugged into an expansion card slot of the host machine, the platform firmware determines whether the expansion card slot has been approved by a user of the host machine for permitting Direct Memory Access (DMA) with the host machine. Unless the expansion card slot has been determined to be approved by the user for permitting Direct Memory Access (DMA) with the host machine, the platform firmware does not allow drivers that might enable DMA to connect to the device and does not grant permission to the expansion card slot and any upstream bridges to conduct Direct Memory Access (DMA) with the host machine.

Securing a host machine against direct memory access (DMA) attacks via expansion card slots

Approaches for locally attesting an operational condition of a computer system during powering on the computer system. Prior to an operating system being loaded, an attestation client, executing on a computer system, analyzes a set of resources of the computer system to create measurement data. The attestation client provides the measurement data to an attestation server executing in a secure enclave on the computer system. The attestation server processes the measurement data and provides the processed measurement data to a remediation server. Upon the computer system being determined to be operationally healthy, the remediation server provides an unlock key to a locked persistent storage to permit the computer system to read the operating system stored on the persistent storage. Thereafter, a BIOS on the computer system may read the operating system and permit the same to be loaded on the computer system.

Kenneth C. Taylor

Papers

Securing a host machine against direct memory access (DMA) attacks via expansion card slots

Local oversight and provisioning of BIOS activity