Abstract:
Systems, apparatuses, and methods for implementing hypervisor post-write notification of processor state register modifications. A write to a state register of the processor may be detected during guest execution. In response to detecting the write to the state register, the processor may trigger microcode to perform the write and copy the new value of the register to a memory location prior to exiting the guest. The hypervisor may be notified of the update to the state register after it occurs, and the hypervisor may be prevented from modifying the value of the guest's state register. The hypervisor may terminate the guest if the update to the state register is unacceptable. Alternatively, the hypervisor may recommend an alternate value to the guest. If the guest agrees, the guest may set the state register to the alternate value recommended by the hypervisor when the guest resumes operation.
Abstract:
A processor includes a cache memory, a first core including an instruction execution unit, and a memory bus coupling the cache memory to the first core. The memory bus is operable to receive a first portion of a cache line of data for the cache memory, the first core is operable to identify a plurality of data requests targeting the cache line and the first portion and select one of the identified plurality of data requests for execution, and the memory bus is operable to forward the first portion to the instruction execution unit and to the cache memory in parallel.
Abstract:
A method includes executing microcode in a processing unit of a processor to implement a machine instruction, wherein the microcode is to manipulate the processing unit to access a peripheral device on a public communication bus at a private address not visible to other devices on the public communication bus and not specified in the machine instruction. A processor includes a public communication bus, a peripheral device coupled to the public communication bus, and a processing unit. The processing unit is to execute microcode to implement a machine instruction. The microcode is to manipulate the processing unit to access a peripheral device on a public communication bus at a private address not visible to other devices on the public communication bus and not specified in the machine instruction.
Abstract:
A method and apparatus for picking load or store instructions is presented. Some embodiments of the method include determining that the entry in the queue includes an instruction that is ready to be executed by the processor based on at least one instruction-based event and concurrently determining cancel conditions based on global events of the processor. Some embodiments also include selecting the instruction for execution when the cancel conditions are not satisfied.
Abstract:
Systems, apparatuses, and methods for implementing virtualized process isolation are disclosed. A system includes a kernel and multiple guest virtual machines (VMs) executing on the system's processing hardware. Each guest VM includes a vShim layer for managing kernel accesses to user space and guest accesses to kernel space. The vShim layer also maintains a set of page tables separate from the kernel page tables. In one embodiment, data in the user space is encrypted and the kernel goes through the vShim layer to access user space data. When the kernel attempts to access a user space address, the kernel exits and the vShim layer is launched to process the request. If the kernel has permission to access the user space address, the vShim layer copies the data to a region in kernel space and then returns execution to the kernel. The vShim layer prevents the kernel from accessing the user space address if the kernel does not have permission to access the user space address. In one embodiment, the kernel space is unencrypted and the user space is encrypted. A state of a guest VM and the vShim layer may be stored in virtual machine control blocks (VMCBs) when exiting the guest VM or vShim layer.
Abstract:
A computing device that handles address translations is described. The computing device includes a hardware table walker and a memory that stores a reverse map table and a plurality of pages of memory. The table walker is configured to use validated indicators in entries in the reverse map table to determine if page accesses are made to pages for which entries are validated. The table walker is further configured to use virtual machine permissions levels information in entries in the reverse map table determine if page accesses for specified operation types are permitted.
Abstract:
A system and method are disclosed for securely receiving data from an input device coupled to a computing system. The system includes an interface configured to receive data from an input device, a coprocessor, and a host computer, wherein the host computer includes an input handler and a host processor. The host processor is configured to execute code in a normal mode and in a privileged mode. The host processor switches from the normal mode to the secure mode upon data being available from the interface while the host computer is in a secure input mode. The input handler receives the data from the interface and sends the received data to the coprocessor responsive to receiving the data while operating in the secure mode.
Abstract:
A processor employs a hardware encryption module in the processor's memory access path to cryptographically isolate secure information. In some embodiments, the encryption module is located at a memory controller (e.g. northbridge) of the processor, and each memory access provided to the memory controller indicates whether the access is a secure memory access, indicating the data associated with the memory access is designated for cryptographic protection, or a non-secure memory access. For secure memory accesses, the encryption module performs encryption (for write accesses) or decryption (for read accesses) of the data associated with the memory access.
Abstract:
A random number generator may include an input configured to receive a plurality of entropy bits generated by an entropy source of a random number generator, wherein the random number generator is configured to generate a plurality of random numbers; and an entropy health monitor coupled with the input, wherein the entropy health monitor is configured to perform a corrective action based on the plurality of entropy bits.
Abstract:
Restricting peripheral device protocols in confidential compute architectures, the method including: receiving a first address translation request from a peripheral device supporting a first protocol, wherein the first protocol supports cache coherency between the peripheral device and a processor cache; determining that a confidential compute architecture is enabled; and providing, in response to the first address translation request, a response including an indication to the peripheral device to not use the first protocol.