1. Para-Partitioning
Brett Warden, Albert Martinez, Saurabh Dadu,
Santosh Balakrishnan
July 25, 2007
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*Other names and brands may be claimed as the property of others.
1 Copyright © 2007, Intel Corporation. All rights reserved.

2. Topics
 Motivation
 What it is
 Advantages
 Limitations
 Para-partitioning vs. Virtualization
 Applications
 How it works
 Demo
2

3. Motivation
 Many existing embedded apps are single-
threaded
– Cannot scale on new multi-core processors
 Control and data-plane historically separate
– Expensive duplication of physical resources
 Applications have different resource needs
– Multiple system designs in a given environment
3

4. What it is
 Multiple logical systems on single physical
system
 Physical resources mapped to logical
systems
 Resource allocation customized to needs of
logical systems
4

5. What it is
N
PCI slot 1
Socket 0 VGA
PCIe slot 2
Front
0 1
USB
PCIe slot 3
2 3 Memory Rear
PCI-X slot 4
USB
PCIe slot 5
Dual
Socket 1
NIC
PCIe slot 6
0
4 5 KB/
SATA Mouse
6 7
PATA Serial
5

6. What it is
N
PCI slot 1
Socket 0 VGA
Memory
PCIe slot 2
Front
0 1
USB
PCIe slot 3
2 3 Rear
PCI-X slot 4
USB
Memory
PCIe slot 5
Dual
Socket 1
NIC
PCIe slot 6
0
4 5 KB/
SATA Mouse Partition 0
6 7 Partition 1
PATA Serial
6

7. What it is
N
PCI slot 1
Socket 0 VGA
Memory
PCIe slot 2
Front
0 1
USB
PCIe slot 3
2 3 Rear
PCI-X slot 4
USB
Memory
PCIe slot 5
Dual
Socket 1
NIC
PCIe slot 6
0
4 5 KB/
SATA Mouse Partition 0
6 7 Partition 1
PATA Serial
7

8. What it isn’t
 Replacement for Virtualization
 Full security solution
 Dynamically configurable
 Completely transparent
8

9. Advantages
 Better multi-core scaling of independent
data flows
 Consolidation of control and data plane
elements
 Without additional latency or VMM overhead
9

10. Limitations
 OSes must be well behaved
 Logical systems require some OS
modifications
– One legacy, unmodified OS can be supported
 Requires cooperative PCI scanning
10

11. Limitations
 Each logical system needs its own
– Processor core
– Memory region
– Any other devices
 No sharing!
 Global system resources must be controlled
by one partition
– Ex. SMM, RTC
11

12. Para-partitioning vs. Virtualization
 Direct hardware access  Hypervisor-emulated
devices
 1:1 resource mapping  Resource Sharing
– Granularity varies
among types of
resources
12

13. Para-partitioning vs. Virtualization
 Hardware-limited  Performance-limited
numbers of logical numbers of guests
systems
 Static resource allocation  Dynamic resource
at boot allocation by hypervisor
13

14. Para-partitioning vs. Virtualization
 Real SMP available to  Emulated SMP available
logical systems to guests
 OS must support  Guests run unmodified
relocation (with hardware
virtualization support)
14

15. Para-partitioning vs. Virtualization
 Not mutually exclusive!
 Complementary
 Demo system uses both
15

16. Applications for Para-partitioning
 Replacing multiple embedded systems
 Leverage multi-core processors via multiple
instances of single-threaded RTOS
 Enforce resource limits on shared systems
 Consolidate different workloads while still
providing some isolation
16

17. Applications for Virtualization
 Consolidate multiple servers
 Hosting services on different OSes
 Virtual hosting for different customers
 Multi-OS development environment
17

18. How Para-partitioning works
 EFI allocates resources among partitions
 EFI spawns additional copies of itself
 Each copy hides other partitions’ devices by
generating a filtered ACPI table
18

19. How Para-partitioning works
Power
On
Boot non- Disable
EFI
legacy OS config
Shell
(Partition 0) writes
Boot legacy
Spawn
EFI Shell OS (Partition
Copy
1)
19

20. Demo
Serial Adapter
N
PCI slot 1
Socket 0 VGA
Memory
PCIe slot 2
Front
0 1 Dual-Port NIC
USB
PCIe slot 3
2 3 Rear
PCI-X slot 4
USB
Memory
PCIe slot 5
Dual
Socket 1
NIC
PCIe slot 6
0
4 5 KB/
SATA Mouse Partition 0
6 7 Partition 1
PATA Serial
20

21. Summary
 Multiple logical systems on single hardware
system
 Direct hardware access (no hypervisor)
 Works best for well-defined, fixed
applications
21

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