我有一台安装了 6 个 NIC 的服务器，运行的是 Ubuntu 12.04LTS。我想使用 kvm 设置 4 个客户虚拟机。现在我想为主机分配 2 个 NIC（1 个公共 IP 和 1 个私有 IP），并为 4 个客户虚拟机各分配 1 个 NIC（所有都是私有 IP）。我该怎么做？
/etc/network/interfaces
我的配置文件出现问题，如下所示：
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.1.109
netmask 255.255.255.0
gateway 192.168.1.5
auto eth1
iface eth1 inet static
address 192.168.1.117
netmask 255.255.255.0
auto eth2
iface eth2 inet manual
auto br0
iface br0 inet static
address 192.168.1.118
netmask 255.255.255.0
bridge_ports eth2
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off
auto eth3
iface eth3 inet manual
auto br1
iface br1 inet static
address 192.168.1.119
netmask 255.255.255.0
bridge_ports eth3
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off
auto eth4
iface eth4 inet manual
auto br2
iface br2 inet static
address 192.168.1.123
netmask 255.255.255.0
bridge_ports eth4
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off
auto eth5
iface eth5 inet manual
auto br3
iface br3 inet static
address 192.168.1.124
netmask 255.255.255.0
bridge_ports eth5
bridge_fd 9
bridge_hello 2
bridge_maxage 12
bridge_stp off
更新：现在它已经正常工作了。唯一的问题是分配给客户机使用的 NIC 仍然在主机上获得 IP，输出如下：
eth0 Link encap:Ethernet HWaddr 78:2b:cb:2b:61:ed
inet addr:192.168.1.109 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7a2b:cbff:fe2b:61ed/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:117 errors:0 dropped:0 overruns:0 frame:0
TX packets:108 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:26221 (26.2 KB) TX bytes:17217 (17.2 KB)
Interrupt:36 Memory:d2000000-d2012800
eth1 Link encap:Ethernet HWaddr 78:2b:cb:2b:61:ee
inet addr:192.168.1.10 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7a2b:cbff:fe2b:61ee/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:40 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9898 (9.8 KB) TX bytes:3409 (3.4 KB)
Interrupt:48 Memory:d4000000-d4012800
eth2 Link encap:Ethernet HWaddr 00:10:18:a8:84:80
inet6 addr: fe80::210:18ff:fea8:8480/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:46 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:11309 (11.3 KB) TX bytes:2523 (2.5 KB)
Interrupt:47 Memory:da000000-da012800
eth3 Link encap:Ethernet HWaddr 00:10:18:a8:84:82
inet6 addr: fe80::210:18ff:fea8:8482/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:51 errors:0 dropped:0 overruns:0 frame:0
TX packets:17 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:12541 (12.5 KB) TX bytes:4154 (4.1 KB)
Interrupt:46 Memory:dc000000-dc012800
eth4 Link encap:Ethernet HWaddr 00:10:18:a8:84:84
inet6 addr: fe80::210:18ff:fea8:8484/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:55 errors:0 dropped:0 overruns:0 frame:0
TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:15136 (15.1 KB) TX bytes:3053 (3.0 KB)
Interrupt:38 Memory:d6000000-d6012800
eth5 Link encap:Ethernet HWaddr 00:10:18:a8:84:86
inet6 addr: fe80::210:18ff:fea8:8486/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:58 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:14742 (14.7 KB) TX bytes:2523 (2.5 KB)
Interrupt:45 Memory:d8000000-d8012800
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:639 errors:0 dropped:0 overruns:0 frame:0
TX packets:639 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:46422 (46.4 KB) TX bytes:46422 (46.4 KB)
macvtap0 Link encap:Ethernet HWaddr 52:54:00:8d:e7:e6
inet6 addr: fe80::5054:ff:fe8d:e7e6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:57 errors:0 dropped:0 overruns:0 frame:0
TX packets:7 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:14074 (14.0 KB) TX bytes:1553 (1.5 KB)
答案1
为客户机分配 NIC 的最简单方法是让它们在主机中保持未配置状态，并对客户机 NIC 使用 macvtap 直通模式。请注意，如果没有额外的、更复杂的设置，这将阻止虚拟机实时迁移。
设置：
<devices>
...
<interface type='direct'>
<source dev='eth0' mode='private'/>
</interface>
</devices>
或者您可以选择完整的 PCI 直通模式（假设您有 IOMMU/VT-d）：
<devices>
<interface type='hostdev'>
<source>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</source>
<mac address='52:54:00:6d:90:02'>
</interface>
</devices>