Volume 2, Part 1: Processor Abstraction Layer
2:343
11.7.4.2.6 Cover Optimization
The cover optimization is enabled by the a_cover bit in the Virtualization Acceleration
Control (
vac
) field in the VPD. When this optimization is enabled, software running with
PSR.vm==1 will be able to execute
cover
instructions without any intercepts to the
VMM, unless a fault condition is detected (see
for details). The
cover
instruction will execute and vcr.ifs will be updated if vpsr.ic is 0.
If this optimization is disabled, execution of the
cover
instruction with PSR.vm==1
results in a virtualization intercept.
Synchronization is required when this optimization is enabled, see
for
details.
When this optimization is enabled, certain VPD state is accessed, as described in
Table 11-16, “Virtual Processor Descriptor (VPD)” on page 2:326
11.7.4.2.7 Bank Switch Optimization
The bank switch optimization is enabled by the a_bsw bit in the Virtualization
Acceleration Control (
vac
) field in the VPD. When this optimization is enabled, execution
of the
bsw
instruction with PSR.vm==1 spills the currently active banked registers and
the corresponding NaT bits to the VPD, and loads the other banked registers and the
Table 11-36. Synchronization Requirements for MOV-from-CPUID
Optimization
VPD Resource
Synchronization Required
vcpuid0-4
Write
Table 11-37. Interruptions when MOV-from-CPUID Optimization is Enabled
Instructions
Interruptions
MOV-from-CPUID
When the MOV-from-CPUID optimization is enabled,
MOV-from-CPUID instructions with PSR.vm==1, may raise the fol-
lowing faults:
• Illegal Operation fault – if the target operand specifies GR 0 or
an out-of-frame stacked register
• Register NaT Consumption fault – if the NaT bit in the target
register is one
• Reserved Register/Field fault – if a reserved CPUID register is
being read
Table 11-38. Synchronization Requirements for Cover Optimization
VPD Resource
Synchronization Required
vifs
Read, Write
Table 11-39. Interruptions when Cover Optimization is Enabled
Instructions
Interruptions
cover
When the cover optimization is enabled,
cover
instructions with
PSR.vm==1, may raise the following faults:
• Illegal Operation fault – if the instruction is not the last instruction
in an instruction group
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 ...