Hard Partitioning: Dynamic Domains - Oracle Solaris 10 System Virtualization Essentials - page 71

major UNIX-based platforms. Each CPU on LSB#00 provides four threads, where
each thread is represented by a unique CPU ID. These CPUs are called virtual
CPUs (or vCPUs) because they are not real CPUs, but rather threads in a core on
a real CPU. These vCPUs are found on SPARC64 VI, which is a dual-core proces-
sor with two threads per core.
Table 2.3 shows how the vCPU identifiers map to the physical cores and proces-
sors on LSB#00. The vCPU IDs jump by a count of 4 when the count continues
on to the next CPU because Oracle Solaris assumes each core should have 8 CPU
IDs and leaves the empty CPU IDs unused when a SPARC64 VI processor is used
in the domain.

Table 2.3 LSB#00 vCPU Mappings to Physical Cores and Processors

Core 0 Core 1

CPU#0 vCPU 0 vCPU 1 vCPU 2 vCPU 3

CPU#1

vCPU 8 vCPU 9 vCPU 10 vCPU 11

CPU#2

vCPU 16 vCPU 17 vCPU 18 vCPU 19

CPU#3 vCPU 24 vCPU 25 vCPU 26 vCPU 27

LSB#15 shows the result when a SPARC64 VII processor is used in a domain.
Because the SPARC64 VII is a quad-core processor with two threads per core,
there are a total of eight threads per CPU, or eight vCPUs. Table 2.4 shows the
mapping of vCPUs to the physical cores and processors on LSB15:

Table 2.4 LSB#15 vCPU Mappings to Physical Cores and Processors

Core 0 Core 1 Core 2 Core 3

CPU#0 vCPU 480 vCPU 481 vCPU 482 vCPU 483 vCPU 484 vCPU 485 vCPU 486 vCPU 487

CPU#1

vCPU 488 vCPU 489 vCPU 490 vCPU 491 vCPU 492 vCPU 493 vCPU 494 vCPU 495

CPU#2

vCPU 496 vCPU 497 vCPU 498 vCPU 499 vCPU 500 vCPU 501 vCPU 502 vCPU 503

CPU#3 vCPU 504 vCPU 505 vCPU 506 vCPU 507 vCPU 508 vCPU 509 vCPU 510 vCPU 511

Notice that the CPU IDs of LSB#15 start at 480—because room is needed for
the IDs of CPUs added later using a lower LSB number. The starting CPU ID of
any LSB is always 32 × LSB#. Thus the CPU IDs of LSB#00 start at 32 × 0 = 0.
The CPU IDs of LSB15 start at 32 × 15 = 480. If an LSB#08 were added, the CPU
IDs of that board would start at 32 × 8 = 256.
This system is very important to understand when using Solaris Containers
inside a Dynamic Domain. Assigning vCPUs to a Container, or zone, along core