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Volume 2, Part 1: Processor Abstraction Layer
2:331
11.7.2
Interruption Handling in a Virtual Environment
For logical processors which have been added to a virtual environment through
PAL_VP_INIT_ENV, all IVA-based interruptions continue to be delivered to the
host IVT
independent of the state of PSR.vm at the time of interruption. All IVA-based
interruptions are serviced by the host IVT pointed to by the IVA (CR2) control register
on the logical processor.
IVA-based interruptions that do not represent virtualization events will be delivered to
the
guest IVT
by the VMM. The guest IVT is specified by the VIVA control register in
the VPD of the virtual processor.
For IVA-based interruption handling during virtual processor operations, PAL provides
maximum flexibility to the VMM by supporting
per-virtual-processor host IVTs
. This
allows the VMM to provide a different host IVT with optimizations specific to a particular
guest operating system on the virtual processor. The VMM can also choose to provide
the same IVT for some or all of the virtual processors in a virtual environment.
Hence, at any time in a virtual environment, the IVA (CR2) control register of the
logical processor will be pointing to either:
• The per-virtual-processor host IVT
• The generic host IVT not specific to any virtual processor
The per-virtual-processor host IVT for each virtual processor is setup by PAL when the
virtual processor is first created (PAL_VP_CREATE) or registered (PAL_VP_REGISTER) in
the virtual environment. The VMM passes a pointer to the host IVT specific to the virtual
processor as an incoming parameter to the PAL_VP_CREATE or PAL_VP_REGISTER
procedures. The per-virtual-processor host IVT is setup to perform long branches to the
corresponding vector of the IVT specified in the incoming parameter for all IVA-based
d_to_pmd
4
Disable PMD write virtualization – If 1, writes to the performance monitor data
registers (PMDs) are not virtualized. Code running with PSR.vm==1 can write
the performance monitor data registers of the logical processor directly and
without handling off to the VMM.
If 0, writes of the performance counter data registers with PSR.vm==1 result
in virtualization intercepts.
d_itm
5
Disable ITM virtualization – If 1, writes to the Interval Timer Match (ITM) regis-
ter are not virtualized. Code running with PSR.vm==1 can write the ITM regis-
ter of the logical processor directly and without handling off to the VMM.
If 0, writes of the ITM register with PSR.vm==1 result in virtualization inter-
cepts.
d_psr_i
6
Disable PSR.i virtualization – If 1, accesses (reads/writes) to the interrupt bit
in processor state register (PSR.i) are not virtualized. Code running with
PSR.vm==1 can read and write only the interrupt bit via the
ssm
and
rsm
instructions directly without handling off to the VMM. Attempts to modify other
PSR bits in addition to the interrupt bit via the
ssm
and
rsm
instructions will
result in virtualization intercepts. Attempts to modify the interrupt bit with the
mov psr.l
instruction will continue to result in virtualization intercepts.
If 0, accesses to the PSR.i bit with PSR.vm==1 result in virtualization inter-
cepts.
Reserved
63:7
Reserved
Table 11-20. Virtualization Disable Control (
vdc
) Fields (Continued)
Field
Bits
Description
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 ...