Abstract: In response to a current context, with a particular process currently in control of a processor requesting access to a shared address space, a translation lookaside buffer (TLB) controller sets a process identifier field in a virtual address to be looked up in a TLB to a clamped value different from an identifier for the process, wherein the virtual address comprises at least the process identifier field and an effective address field set to an address in the requested shared address space. In response to the TLB controller comparing the virtual address for the current context to a particular entry of at least one entry within the TLB comprising the at least one entry stored for a previous translation of a previous virtual address, the TLB controller only indicates a match between the process identifier field and a translation process identifier field within the particular entry of the TLB if the translation process identifier field is also set to the clamped value.

Abstract: For a current context in control of a processor requesting access to a particular address, a translation lookaside buffer (TLB) controller specifies a virtual address with a logical partition identifier value indicating a privilege setting of the current context, a process identifier value indicating whether the address is within shared address space, and an effective address comprising at least a portion of the particular address.

Abstract: In response to a current context, with a particular process currently in control of a processor requesting access to a shared address space, a translation lookaside buffer (TLB) controller sets a process identifier field in a virtual address to be looked up in a TLB to a clamped value different from an identifier for the process, wherein the virtual address comprises at least the process identifier field and an effective address field set to an address in the requested shared address space. In response to the TLB controller comparing the virtual address for the current context to a particular entry of at least one entry within the TLB comprising the at least one entry stored for a previous translation of a previous virtual address, the TLB controller only indicates a match between the process identifier field and a translation process identifier field within the particular entry of the TLB if the translation process identifier field is also set to the clamped value.

Abstract: Disclosed are computers and methods employing a mechanism for eliminating a race condition between a hypervisor-performed emulation process and a concurrent translation table entry invalidation. Specifically, on a host machine, a hypervisor controls any guest operating systems. In doing so, the hypervisor emulates an instruction by performing a translation operation to acquire a physical address from a virtual address and, if applicable, further from an effective address using translation table(s) (e.g., page tables and, if applicable, segment tables); accesses the physical address; and completes the instruction. During emulation, flagged address table(s) are used to eliminate the race condition. For example, upon receiving an invalidate translation instruction associated with a virtual address, a determination is made as to whether or not the virtual address appears in a flagged virtual address table and, if so, additional action is taken to prevent an error in the translation.

Abstract: In response to a current context, with a particular process currently in control of a processor requesting access to a shared address space, a translation lookaside buffer (TLB) controller sets a process identifier field in a virtual address to be looked up in a TLB to a clamped value different from an identifier for the process, wherein the virtual address comprises at least the process identifier field and an effective address field set to an address in the requested shared address space. In response to the TLB controller comparing the virtual address for the current context to a particular entry of at least one entry within the TLB comprising the at least one entry stored for a previous translation of a previous virtual address, the TLB controller only indicates a match between the process identifier field and a translation process identifier field within the particular entry of the TLB if the translation process identifier field is also set to the clamped value.

Abstract: For a current context in control of a processor requesting access to a particular address, a translation lookaside buffer (TLB) controller specifies a virtual address with a logical partition identifier value indicating a privilege setting of the current context, a process identifier value indicating whether the address is within shared address space, and an effective address comprising at least a portion of the particular address.

Abstract: In response to a current context, with a particular process currently in control of a processor requesting access to a shared address space, a translation lookaside buffer (TLB) controller sets a process identifier field in a virtual address to be looked up in a TLB to a clamped value different from an identifier for the process, wherein the virtual address comprises at least the process identifier field and an effective address field set to an address in the requested shared address space. In response to the TLB controller comparing the virtual address for the current context to a particular entry of at least one entry within the TLB comprising the at least one entry stored for a previous translation of a previous virtual address, the TLB controller only indicates a match between the process identifier field and a translation process identifier field within the particular entry of the TLB if the translation process identifier field is also set to the clamped value.

Abstract: For a current context in control of a processor requesting access to a particular address, a translation lookaside buffer (TLB) controller specifies a virtual address with a logical partition identifier value indicating a privilege setting of the current context, a process identifier value indicating whether the address is within shared address space, and an effective address comprising at least a portion of the particular address.

Abstract: Disclosed are computers and methods employing a mechanism for eliminating a race condition between a hypervisor-performed emulation process and a concurrent translation table entry invalidation. Specifically, on a host machine, a hypervisor controls any guest operating systems. In doing so, the hypervisor emulates an instruction by performing a translation operation to acquire a physical address from a virtual address and, if applicable, further from an effective address using translation table(s) (e.g., page tables and, if applicable, segment tables); accesses the physical address; and completes the instruction. During emulation, flagged address table(s) are used to eliminate the race condition. For example, upon receiving an invalidate translation instruction associated with a virtual address, a determination is made as to whether or not the virtual address appears in a flagged virtual address table and, if so, additional action is taken to prevent an error in the translation.

Abstract: In response to a determination to allocate additional storage, within a real address space employed by a system memory of a data processing system, for translation control entries (TCEs) that translate addresses from an input/output (I/O) address space to the real address space, a determination is made whether or not a first real address range contiguous with an existing TCE data structure is available for allocation. In response to determining that the first real address range is available for allocation, the first real address range is allocated for storage of TCEs, and a number of levels in the TCE data structure is retained. In response to determining that the first real address range is not available for allocation, a second real address range discontiguous with the existing TCE data structure is allocated for storage of the TCEs, and a number of levels in the TCE data structure is increased.

Abstract: In response to a determination to allocate additional storage, within a real address space employed by a system memory of a data processing system, for translation control entries (TCEs) that translate addresses from an input/output (I/O) address space to the real address space, a determination is made whether or not a first real address range contiguous with an existing TCE data structure is available for allocation. In response to determining that the first real address range is available for allocation, the first real address range is allocated for storage of TCEs, and a number of levels in the TCE data structure is retained. In response to determining that the first real address range is not available for allocation, a second real address range discontiguous with the existing TCE data structure is allocated for storage of the TCEs, and a number of levels in the TCE data structure is increased.

Abstract: A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic runs the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

Abstract: A computer implemented method searches a unified translation lookaside buffer. Responsive to a request to access the unified translation lookaside buffer, a first order code within a first entry of a search priority configuration register is identified. A unified translation lookaside buffer is then searched according to the first order code for a hashed page entry. If the hashed page entry is not found when searching a unified translation lookaside buffer according to the first order code, a second order code is identified within a second entry of the search priority configuration register. The unified translation lookaside buffer is then searched according to the second order code for the hashed page entry.

Abstract: A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic runs the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

Abstract: An enhanced mechanism for loading entries into a translation lookaside buffer (TLB) in hardware via indirect TLB entries. In one embodiment, if no direct TLB entry associated with the given virtual address is found in the TLB, the TLB is checked for an indirect TLB entry associated with the given virtual address. Each indirect TLB entry provides the real address of a page table associated with a specified range of virtual addresses and comprises an array of page table entries. If an indirect TLB entry associated with the given virtual address is found in the TLB, a computed address is generated by combining a real address field from the indirect TLB entry and bits from the given virtual address, a page table entry (PTE) is obtained by reading a word from a memory at the computed address, and the PTE is loaded into the TLB as a direct TLB entry.

Abstract: A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic executes the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

Abstract: Mechanisms are provided, in a data processing system having a processor and a transactional memory, for executing a transaction in the data processing system. These mechanisms execute a transaction comprising one or more instructions that modify at least a portion of the transactional memory. The transaction is suspended in response to a transaction suspend instruction being executed by the processor. A suspended block of code is executed in a non-transactional manner while the transaction is suspended. A determination is made as to whether an interrupt occurs while the transaction is suspended. In response to an interrupt occurring while the transaction is suspended, a transaction abort operation is delayed until after the transaction suspension is discontinued.

Abstract: A computer implemented method searches a unified translation lookaside buffer. Responsive to a request to access the unified translation lookaside buffer, a first order code within a first entry of a search priority configuration register is identified. A unified translation lookaside buffer is then searched according to the first order code for a hashed page entry. If the hashed page entry is not found when searching a unified translation lookaside buffer according to the first order code, a second order code is identified within a second entry of the search priority configuration register. The unified translation lookaside buffer is then searched according to the second order code for the hashed page entry.

Abstract: A method and a system for allowing a guest operating system (guest OS) to modify an entry in a TLB directly without an involvement of a hypervisor are disclosed. Upon receiving a guest TLB miss exception, a guest OS issues a TLBWE (TLB Write Entry) instruction to logic. The logic executes the TLBWE instruction at a supervisor mode without invoking a hypervisor. The TLB may incorporate entries in a guest page table and entries in a host page table.

Abstract: An enhanced mechanism for loading entries into a translation lookaside buffer (TLB) in hardware via indirect TLB entries. In one embodiment, if no direct TLB entry associated with the given virtual address is found in the TLB, the TLB is checked for an indirect TLB entry associated with the given virtual address. Each indirect TLB entry provides the real address of a page table associated with a specified range of virtual addresses and comprises an array of page table entries. If an indirect TLB entry associated with the given virtual address is found in the TLB, a computed address is generated by combining a real address field from the indirect TLB entry and bits from the given virtual address, a page table entry (PTE) is obtained by reading a word from a memory at the computed address, and the PTE is loaded into the TLB as a direct TLB entry.