US 8,819,648 B2Granted

Control flow management for execution of dynamically translated non-native code in a virtual hosting environment

AssigneeInternational Business Machines Corporation

InventorAlexander Barraclough Brown

Life of this patent

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Abstract

Execution of non-native operating system images within a virtualized computer system is improved by providing a mechanism for retrieving translated code physical addresses corresponding to un-translated code branch target addresses using a host code map. Hardware acceleration mechanisms, such as content-accessible look-up tables, directory hardware, or processor instructions that operate on tables in memory can be provided to accelerate the performance of the translation mechanism. The virtual address of the branch instruction target is used as a key to look up a corresponding record that contains a physical address of the translated code page containing the translated branch instruction target, and execution is directed to the physical address obtained from the record, once the physical page containing the translated code corresponding the target address is loaded in memory.

Claims24

Dependent claims

A computer-performed method for hosting guest program code having a non-native instruction set executing within a host operating system within a virtualized computer system, the method comprising:

dynamically translating the guest program code to translated native program code;
caching pages of the translated native program code in a translated native code page cache;
executing the translated native program code;
detecting that a portion of the translated native program code corresponding to a non-native branch instruction will cause the executing to be directed to a particular translated code physical address corresponding to a particular non-native virtual address in a different first non-native virtual memory page than a second non-native virtual memory page containing the non-native branch instruction;
responsive to detecting that the program control instruction will cause the executing to be directed to the particular translated code physical address, retrieving a record indicating a location of a translated code page containing the particular translated code physical address using the particular non-native virtual address as a key into a host code map that directly maps non-native virtual addresses to translated code physical addresses, wherein the retrieving comprises adding the particular non-native virtual address to a base address of the host code map to obtain a pointer into the host code map corresponding to an address at which the record is stored and de-referencing the pointer to obtain the record;
loading the translated code page into physical memory;
and
directing the executing to the particular translated code physical address in the translated code page.

5 more elements

A computer system comprising a processor for executing program instructions and a memory coupled to the processor for executing the program instructions, wherein the program instructions implement a host operating system hosting guest program code having a non-native instruction set within a virtual processing machine instance executing within the computer system, wherein the program instructions comprise program instructions for:

dynamically translating the guest program code to translated native program code;
caching pages of the translated native program code in a translated native code page cache;
executing the translated native program code;
detecting that a portion of the translated native program code corresponding to a non-native branch instruction will cause the executing to be directed to a particular translated code physical address corresponding to a particular non-native virtual address in a different first non-native virtual memory page than a second non-native virtual memory page containing the non-native branch instruction;
responsive to detecting that the program control instruction will cause the executing to be directed to the particular translated code physical address, retrieving a record indicating a location of a translated code page containing the particular translated code physical address using the particular non-native virtual address as a key into a host code map that directly maps non-native virtual addresses to translated code physical addresses, wherein the program instructions for retrieving comprise program instructions for adding the particular non-native virtual address to a base address of the host code map to obtain a pointer into the host code map corresponding to an address at which the record is stored and de-referencing the pointer to obtain the record;
loading the translated code page into physical memory;
and
directing the executing to the particular translated code physical address in the translated code page.

5 more elements

A computer program product comprising a computer-readable storage device storing program instructions for execution within a computer system, wherein the program instructions implement a host operating system for hosting guest program code having a non-native instruction set within a virtual processing machine instance within the computer system, wherein the program instructions comprise program instructions for:

dynamically translating the guest program code to translated native program code;
caching pages of the translated native program code in a translated native code page cache;
executing the translated native program code;
detecting that a portion of the translated native program code corresponding to a non-native branch instruction will cause the executing to be directed to a particular translated code physical address corresponding to a particular non-native virtual address in a different first non-native virtual memory page than a second non-native virtual memory page containing the non-native branch instruction;
responsive to detecting that the program control instruction will cause the executing to be directed to the particular translated code physical address, retrieving a record indicating a location of a translated code page containing the particular translated code physical address using the particular non-native virtual address as a key into a host code map that directly maps non-native virtual addresses to translated code physical addresses, wherein the program instructions for retrieving comprise program instructions for adding the particular non-native virtual address to a base address of the host code map to obtain a pointer into the host code map corresponding to an address at which the record is stored and de-referencing the pointer to obtain the record;
loading the translated code page into physical memory;
and
directing the executing to the particular translated code physical address in the translated code page.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/554,141Filed 20 Jul 2012
Published: US 2014/0025893 A123 Jan 2014
Granted: 26 Aug 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G06F 12/1027
Address translation: using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
G06F 9/30174
Runtime instruction translation, e.g. macros: for non-native instruction set, e.g. Javabyte, legacy code
G06F 9/3804
Instruction prefetching: for branches, e.g. hedging, branch folding
G06F 9/45516
Abstract machines for program code execution, e.g. Java virtual machine [JVM], interpreters or emulators: runtime code conversion or optimisation