Volume 2, Part 1: Processor Abstraction Layer
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11.7.4.1.2 Virtualization Cause Optimization
Virtualization cause optimization is enabled by the
cause
bit in the
config_options
parameter of PAL_VP_INIT_ENV. When enabled, the causes of virtualization intercepts
will be provided to the VMM during PAL intercept handoffs within the virtual
environment. When disabled, no cause information will be provided during PAL
intercept handoffs.
This optimization requires no special synchronization.
11.7.4.1.3 Guest MOV-from-AR.ITC Optimization
Guest MOV-from-AR.ITC optimization allows software running with PSR.vm==1 to
execute MOV-from-AR.ITC instructions without any intercepts to the VMM. The value
returned will be the sum of the value in the interval timer counter register (ITC) and
interval timer offset register (ITO), unless a fault condition is detected (see
Table 11-25, “Behavior of Guest MOV-from-AR.ITC Instruction in Virtual Environment”
for details). The VMM is responsible for programming the ITO register to provide the
desired return value for guest execution with PSR.vm = 1 of the MOV-from-ITC
instruction when this optimization is enabled.
This optimization is enabled by the
gitc
bit in the
config_options
parameter of
PAL_VP_INIT_ENV. The behavior of the guest MOV-from-AR.ITC instruction is affected
by the settings of psr.ic and vpsr.ic as well, as shown in
This optimization requires no special synchronization.
This optimization is not supported on all processor implementations. Software can call
PAL_VP_ENV_INFO to determine the availability of this feature.
11.7.4.2
Virtualization Accelerations
summarizes the virtualization accelerations supported in Itanium
architecture.
Table 11-25.Behavior of Guest MOV-from-AR.ITC Instruction in Virtual Envi-
ronment
gitc
a
a. gitc=0: Optimization disabled; gitc=1: Optimization enabled.
psr.si
vpsr.si
MOV-from-AR.ITC when PSR.vm==1
0
0
0
No virtualization intercept – guest reads AR.ITC
0
1
Invalid setting – behavior is undefined.
1
0
Virtualization intercept
1
1
If vpsr.cpl is not zero: Privileged Register fault
If vpsr.cpl is zero: Virtualization intercept
1
0
0
No virtualization intercept – guest reads the sum of ITC and ITO
0
1
If vpsr.cpl is not zero: Privileged Register fault
If vpsr.cpl is zero: No Virtualization intercept – guest reads the sum of ITC and ITO
1
0
Virtualization intercept.
1
1
If vpsr.cpl is not zero: Privileged Register fault
If vpsr.cpl is zero: Virtualization intercept
Summary of Contents for ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Page 1: ......
Page 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Page 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Page 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Page 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
Page 230: ......
Page 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Page 380: ...2 132 Volume 2 Part 1 Interruptions ...
Page 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Page 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Page 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Page 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Page 808: ...2 560 Volume 2 Part 2 Context Management ...
Page 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Page 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Page 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Page 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
Page 891: ......
Page 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Page 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
Page 1296: ......
Page 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...