APIC EOI Message
An APIC EOI message is delivered by the hypervisor after a virtual processor executes an instruction that writes to the APIC's memory-mapped EOI register or APIC EOI MSR, which indicates the end of interrupt. This message is generated only for level-triggered fixed or external interrupts.
The format of APIC EOI messages is shown in the following table. The HV_X64_APIC_EOI_MESSAGE structure is used to encode APIC EOI messages.
|
Message Header | |||
|
0 |
MessageType (4 bytes) |
Rsvd (3 bytes) |
PayloadSize (1 byte) |
|
8 |
SourcePartition (8 bytes) | ||
|
APIC EOI Payload | |||
|
16 |
VpIndex (4 bytes) |
InterruptVector (4 bytes) | |
The following list describes the fields of APIC EOI messages:
- VpIndex
-
The index of the virtual processor.
- InterruptVector
-
The vector of the interrupt that recently completed EOI.
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Build date: 11/16/2013