Ethtool 将 "Speed" 和 "Duplex" 显示为 "Unknown" (16563881)

在 Oracle VM 3.2.7 服务器上使用 ethtool 命令时，"Speed" 和 "Duplex" 设置显示 "Unknown!" 状态。如下例所示：

# ethtool eth0
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: Symmetric
        Advertised auto-negotiation: Yes
        Speed: Unknown!
        Duplex: Unknown! (255)
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: pumbg
        Wake-on: d
        Current message level: 0x00000007 (7)
        Link detected: no 

该问题是由于可用于报告相应状态的中断资源不足导致的。

解决办法

编辑 grub.conf 文件以添加以下内核引导参数：

extra_guest_irqs=64,2048 nr_irqs=2048