2. 2
VMの切り替え時間(AMD)
0
200
400
600
800
1000
1200
1400
1600
Barcelona Shanghai
cycles
World Switch Time (lower value is better)
World Switch Time
4
注目点
• CPUの仮想化支援機能が進化したので
– VMware
• VMI(Virtual Machine Interface)のサポート中止
– 準仮想化よりCPUの仮想化支援機能を使った方が、ベン
チマークテストで高性能とLinux Kernel MLで報告して将来
のプロダクトでのサポート中止を宣言
• 最新CPUでは、BT(binary translation)は不使用
– デフォルトでは、VT-x + EPT もしくは AMD-V + RVIを利用
– Xen
• hybrid virtualization?
5
3. 3
LKML
6
差出人: akataria@vmware.com
件名: Paravirtualization on VMware's Platform [VMI].
日時: 2009年9月18日 9:17:08:JST
Hi,
We ran a few experiments to compare performance of VMware's
paravirtualization technique (VMI) and hardware MMU technologies (HWMMU)
on VMware's hypervisor.
省略
Please note that specjbb is the worst case benchmark for hwmmu, due to
the higher TLB miss latency, so it's a good result that the worst case
benchmark has a degradation of only 1%.
VMware expects that these hardware virtualization features will be
ubiquitous by 2011.
Apart from the performance benefit, VMI was important for Linux on
VMware's platform, from timekeeping point of view, but with the tickless
kernels and TSC improvements that were done for the mainline tree, we
think VMI has outlived those requirements too.
In light of these results and availability of such hardware, we have
decided to stop supporting VMI in our future products.
省略
vSphere4 monitor modes
4
VMWARE WHITE PAPER
Table 1: Default monitor modes on Intel processors
Virtual Machine
Configuration
Core i7 45nm Core2
with VT-x
65nm Core2
with VT-x and
FlexPriority
65nm Core2
with VT-x
and No
FlexPriority
P4 with VT-x EM64T
without VT-x
No EM64T
FT enabled VT-x +
swMMU
VT-x + swMMU VT-x + swMMU VT-x + swMMU Not Runnable Not Runnable Not Runnable
64-bit Guests VT-x + EPT VT-x + swMMU VT-x + swMMU VT-x + swMMU VT-x + swMMU Not Runnable Not Runnable
VMI enabled(**) BT +
swMMU
BT + swMMU BT + swMMU BT + swMMU BT + swMMU BT + swMMU BT + swMMU
OpenServer
UnixWare
VT-x + EPT VT-x + swMMU VT-x + swMMU VT-x + swMMU VT-x + swMMU BT + swMMU BT + swMMU
OS/2 VT-x + EPT VT-x + swMMU VT-x + swMMU VT-x + swMMU VT-x + swMMU Not Runnable Not Runnable
32-bit Linux
32-bit FreeBSD
VT-x + EPT VT-x + swMMU BT + swMMU (*) BT + swMMU (*) BT + swMMU (*) BT + swMMU BT + swMMU
32-bit Windows:
XP, Vista, Server
2003, Server 2008
VT-x + EPT VT-x + swMMU VT-x + swMMU BT + swMMU (*) BT + swMMU (*) BT + swMMU BT + swMMU
Windows 2000,
NT, 95, 98, DOS,
Netware, 32-bit
Solaris
BT +
swMMU (*)
BT + swMMU (*) BT + swMMU (*) BT + swMMU (*) BT + swMMU (*) BT + swMMU BT + swMMU
Other 32-bit Guests VT-x + EPT VT-x + swMMU VT-x + swMMU VT-x + swMMU VT-x + swMMU BT + swMMU BT + swMMU
(*) When BT is used on an Intel system with VT-x capability, it dynamically switches to VT-x if the guest enters long mode.
(**) In VMI, para-virtualization is used for CPU and MMU virtualization. The guest kernel is statically modified to make hyper-calls into
the VMM to execute privileged instructions and perform page table updates [5].
Table 2: Intel processor technology and common server processors
Processor technology (from some columns of Table 1) Server processors
Core i7 Intel Xeon 5500 series
45nm Core 2 with VT-x Intel Xeon 5400 series
Intel Xeon 7400 series
65nm Core 2 with VT-x and FlexPriority Intel Xeon 7300 series
65nm Core 2 with VT-x and No FlexPriority Intel Xeon 5300 series
7
出典 http://www.vmware.com/files/pdf/perf-vsphere-monitor_modes.pdf 4p