Virtualised interface functions
First Claim
1. A data processing system comprising:
- a memory addressable by a range of physical memory addresses;
at least one first software domain having a first privilege level and supporting a trusted I/O management entity;
a plurality of second software domains each having a privilege level which is below the first privilege level and each having a virtual memory address space;
a memory management unit configured to perform virtual address translation of a virtual memory address into a physical memory address; and
an input and/or output device supporting a plurality of virtualised interfaces, each virtualised interface being associated with a respective one of the non-privileged software domains, the input and/or output device further comprising an address translation data store maintained up-to-date by the trusted I/O management entity and at least one operation management unit having access to the address translation data store and being configured to perform virtual address translation in one or more of the virtual memory address spaces;
wherein, for I/O operations requested by a virtualised interface of the input and/or output device, the input and/or output device is configured to invoke the operation management unit to perform virtual address translation for those I/O operations meeting one or more predefined first criteria and to invoke the memory management unit to perform virtual address translation for those I/O operations which do not meet the one or more predefined first criteria.
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Accused Products
Abstract
Roughly described, a data processing system comprises a memory addressable by a range of physical memory addresses; a plurality of non-privileged software domains each having a virtual memory address space; a privileged software domain; a memory management unit operable to perform virtual address translation of a virtual memory address into a physical memory address; and an I/O device supporting virtualised interfaces each associated with a respective non-privileged software domain, the I/O device comprising an operation management unit operable to perform virtual address translation in one or more of the virtual memory address spaces; wherein, for I/O operations requested by a virtualised interface, the I/O device invokes the operation management unit to perform virtual address translation for those I/O operations meeting first criteria and to invoke the memory management unit to perform virtual address translation for those I/O operations which do not meet the first criteria.
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Citations
38 Claims
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1. A data processing system comprising:
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a memory addressable by a range of physical memory addresses; at least one first software domain having a first privilege level and supporting a trusted I/O management entity; a plurality of second software domains each having a privilege level which is below the first privilege level and each having a virtual memory address space; a memory management unit configured to perform virtual address translation of a virtual memory address into a physical memory address; and an input and/or output device supporting a plurality of virtualised interfaces, each virtualised interface being associated with a respective one of the non-privileged software domains, the input and/or output device further comprising an address translation data store maintained up-to-date by the trusted I/O management entity and at least one operation management unit having access to the address translation data store and being configured to perform virtual address translation in one or more of the virtual memory address spaces; wherein, for I/O operations requested by a virtualised interface of the input and/or output device, the input and/or output device is configured to invoke the operation management unit to perform virtual address translation for those I/O operations meeting one or more predefined first criteria and to invoke the memory management unit to perform virtual address translation for those I/O operations which do not meet the one or more predefined first criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A method for handling virtual memory addresses at a data processing system comprising a memory and an input and/or output device, the data processing system supporting (a) at least one privileged software domain and (b) a plurality of non-privileged software domains each having a virtual memory address space and each being associated with a respective virtualised interface of the input and/or output device, the method comprising:
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receiving at a virtualised interface of the input and/or output device at least one virtual memory address from the respective one of the non-privileged software domains; the virtualised interface requesting an I/O operation using the at least one virtual memory address; determining at the input and/or output device whether the I/O operation request meets one or more predefined first criteria; and; if the one or more first criteria are met, performing translation of the virtual memory address into a physical memory address at an operation management unit of the input and/or output device, the operation management unit having access to an address translation data store of the input and/or output device which is maintained up-to-date by a trusted I/O management entity of the privileged software domain; otherwise, invoking a memory management unit of the data processing system to perform translation of the virtual memory address into a physical memory address. - View Dependent Claims (38)
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Specification