在直通网卡时遇到很多问题，有些甚至莫名其妙，记录下来备用。
1 - missing uar aborting
直通网卡时因驱动问题造成的 missing uar aborting 错误
故障描述
网卡直通给到虚拟机后，lspci 能看到设备：
lspci | grep Mel
01:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
02:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
lspci -k
可以看到网卡的驱动情况如下：
01:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
Subsystem: Hewlett-Packard Company InfiniBand FDR/Ethernet 10Gb/40Gb 2-port 544+FLR-QSFP Adapter
Kernel driver in use: vfio-pci
Kernel modules: mlx4_core
02:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
Subsystem: Hewlett-Packard Company InfiniBand FDR/Ethernet 10Gb/40Gb 2-port 544+FLR-QSFP Adapter
Kernel driver in use: vfio-pci
Kernel modules: mlx4_core
但是直通给虚拟机之后，在虚拟机中网卡无法识别，networkctl 看不到设备：
networkctl
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 enp6s18 ether routable configured
2 links listed.
lsmod 时发现只有 mlx4_core , 没有其他比如 mlx4_en：
lsmod | grep mlx
mlx4_core 311296 0
对比正常情况下的 lsmod 输出应该是这样的：
lsmod | grep mlx
mlx4_ib 245760 0
ib_uverbs 163840 1 mlx4_ib
mlx4_en 155648 0
ib_core 393216 2 mlx4_ib,ib_uverbs
mlx4_core 405504 2 mlx4_ib,mlx4_en
查找问题
在 pve 机器中同样执行 lsmod | grep mlx 命令，会发现存在和在虚拟机中同样的问题，输出中也只有 mlx4_core：
lsmod | grep mlx
mlx4_core 462848 0
重新安装 ubuntu server 也无法解决这个问题。而且安装 ubuntu server 20.04 时，在最开始的启动界面，会看到类似这样的错误提示：
mlx4_core 0000:01:00.0: Missing UAR, aborting
在 pve 操作系统中执行命令：
dmesg | grep mlx
也会看到类似的输出：
[ 2.364990] mlx4_core: Mellanox ConnectX core driver v4.0-0
[ 2.365005] mlx4_core: Initializing 0000:01:00.0
[ 2.365098] mlx4_core 0000:01:00.0: Missing UAR, aborting
[ 2.365214] mlx4_core: Initializing 0000:02:00.0
[ 2.365309] mlx4_core 0000:02:00.0: Missing UAR, aborting
执行命令：
dmesg | grep mlx
输出类似为：
mlx_compat: loading out-of-tree module taints kernel.[0.991286] mlx_compat: module verification failed: signature and/or required key missing - tainting kernel[0.992456] mlx4_core: Mellanox ConnectX core driver v4.1-1.0.2 (27 Jun 2017)[0.992479] mlx4_core: Initializing 0000:01:00.0[0.992621] mlx4_core 0000:01:00.0: Missing UAR, aborting
基本可以判断存在某个问题导致网卡驱动无法正确加载，从而导致网卡无法识别和驱动。
修复方式
增加 “pci=realloc=off” 参数
google之后发现有人遇到类似的问题，验证可行：
https://forums.developer.nvidia.com/t/mlx4-core-missing-uar-aborting/207322/2
按照这里的意思，应该增加 pci=realloc=off ：
- edit /etc/default/grub
- add GRUB_CMDLINE_LINUX_DEFAULT=“pci=realloc=off”
- update-grub
- Reboot
修改主板 bios 设置，开启 ASPM
在华硕z87-a主板，还需要在 bios 中打开 ASPM 相关的选项。
2 - IRQ冲突
直通网卡时因 IRQ 冲突造成不可用
故障描述
插入多块网卡后设置直通，在虚拟机启动时报错，错误描述如下：
kvm: -device vfio-pci,host=0000:01:00.0,id=hostpci1,bus=ich9-pcie-port-2,addr=0x0: vfio 0000:01:00.0: Failed to set up TRIGGER eventfd signaling for interrupt INTX-0: VFIO_DEVICE_SET_IRQS failure: Device or resource busy
TASK ERROR: start failed: QEMU exited with code 1
查找问题
检查 INTx disable
参考这个帖子的描述：
https://forums.unraid.net/topic/120895-passing-a-capture-card-to-vms/
可以用下面这个 check.sh 脚本来检查网卡是否设置了 INTx disable ：
#!/bin/sh
# Usage $0 <PCI device>, ex: 9:00.0
INTX=$(( 0x400 ))
ORIG=$(( 0x$(setpci -s $1 4.w) ))
if [ $(( $INTX & $ORIG )) -ne 0 ]; then
echo "INTx disable supported and enabled on $1"
exit 0
fi
NEW=$(printf %04x $(( $INTX | $ORIG )))
setpci -s $1 4.w=$NEW
NEW=$(( 0x$(setpci -s $1 4.w) ))
if [ $(( $INTX & $NEW )) -ne 0 ]; then
echo "INTx disable support available on $1"
else
echo "INTx disable support NOT available on $1"
fi
NEW=$(printf %04x $ORIG)
setpci -s $1 4.w=$NEW
执行结果如下：
➜ ~ ./check.sh 01:00.0
INTx disable support available on 01:00.0
➜ ~ ./check.sh 04:00.0
INTx disable support available on 04:00.0
➜ ~ ./check.sh 08:00.0
INTx disable support available on 08:00.0
➜ ~ ./check.sh 09:00.0
INTx disable supported and enabled on 09:00.0
检查启动日志
可以执行
dmesg
查看 pve 的启动日志，找到其中报错的内容：
[ 3852.066855] vfio-pci 0000:04:00.0: vfio_ecap_init: hiding ecap 0x19@0x18c
[ 3852.210816] vfio-pci 0000:01:00.0: vfio_ecap_init: hiding ecap 0x19@0x18c
[ 3852.219438] genirq: Flags mismatch irq 16. 00000000 (vfio-intx(0000:01:00.0)) vs. 00000000 (vfio-intx(0000:04:00.0))
3940.230432] vfio-pci 0000:04:00.0: vfio_ecap_init: hiding ecap 0x19@0x18c
[ 3940.374391] vfio-pci 0000:08:00.0: vfio_ecap_init: hiding ecap 0x19@0x18c
[ 3940.383218] genirq: Flags mismatch irq 16. 00000000 (vfio-intx(0000:08:00.0)) vs. 00000000 (vfio-intx(0000:04:00.0))
查看 IRQ 情况
IRQ 情况可以这样查看：
cat /proc/interrupts
输出为：
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 CPU8 CPU9 CPU10 CPU11
0: 11 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 2-edge timer
8: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 8-edge rtc0
9: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 9-fasteoi acpi
14: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 14-fasteoi INTC1056:00
18: 0 0 0 5 0 0 0 0 0 0 0 0 IR-IO-APIC 18-fasteoi i801_smbus
27: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 27-fasteoi idma64.0, i2c_designware.0
29: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 29-fasteoi idma64.2, i2c_designware.2
40: 0 0 0 0 0 0 0 0 0 0 0 0 IR-IO-APIC 40-fasteoi idma64.1, i2c_designware.1
120: 0 0 0 0 0 0 0 0 0 0 0 0 DMAR-MSI 0-edge dmar0
121: 0 0 0 0 0 0 0 0 0 0 0 0 DMAR-MSI 1-edge dmar1
122: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:01.0 0-edge PCIe PME, aerdrv
123: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1a.0 0-edge PCIe PME, pciehp
124: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1b.0 0-edge PCIe PME
125: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1b.4 0-edge PCIe PME, aerdrv
126: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1c.0 0-edge PCIe PME, pciehp
127: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1c.1 0-edge PCIe PME, aerdrv
128: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1c.2 0-edge PCIe PME, aerdrv
129: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1c.4 0-edge PCIe PME, aerdrv
130: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1d.0 0-edge PCIe PME, aerdrv
131: 0 0 13081 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:17.0 0-edge ahci[0000:00:17.0]
132: 0 0 0 0 1083661 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:06:00.0 0-edge enp6s0
133: 0 0 0 0 90 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:14.0 0-edge xhci_hcd
134: 0 0 0 0 0 88674 0 0 0 0 0 0 IR-PCI-MSIX-0000:07:00.0 0-edge enp7s0
210: 0 0 0 0 0 0 0 0 0 0 0 74 IR-PCI-MSIX-0000:09:00.0 0-edge mlx4-async@pci:0000:09:00.0
211: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 1-edge mlx4-1@0000:09:00.0
212: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 2-edge mlx4-2@0000:09:00.0
213: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 3-edge mlx4-3@0000:09:00.0
214: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 4-edge mlx4-4@0000:09:00.0
215: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 5-edge mlx4-5@0000:09:00.0
216: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 6-edge mlx4-6@0000:09:00.0
217: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 7-edge mlx4-7@0000:09:00.0
218: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 8-edge mlx4-8@0000:09:00.0
219: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 9-edge mlx4-9@0000:09:00.0
220: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 10-edge mlx4-10@0000:09:00.0
221: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 11-edge mlx4-11@0000:09:00.0
222: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 12-edge mlx4-12@0000:09:00.0
223: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 13-edge mlx4-13@0000:09:00.0
224: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 14-edge mlx4-14@0000:09:00.0
225: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 15-edge mlx4-15@0000:09:00.0
226: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 16-edge mlx4-16@0000:09:00.0
227: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 17-edge mlx4-17@0000:09:00.0
228: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 18-edge mlx4-18@0000:09:00.0
229: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 19-edge mlx4-19@0000:09:00.0
230: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 20-edge mlx4-20@0000:09:00.0
231: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 21-edge mlx4-21@0000:09:00.0
232: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 22-edge mlx4-22@0000:09:00.0
233: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 23-edge mlx4-23@0000:09:00.0
234: 0 0 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSIX-0000:09:00.0 24-edge mlx4-24@0000:09:00.0
235: 0 49 0 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:16.0 0-edge mei_me
236: 0 0 271 0 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:02.0 0-edge i915
237: 0 0 0 750 0 0 0 0 0 0 0 0 IR-PCI-MSI-0000:00:1f.3 0-edge snd_hda_intel:card0
NMI: 1 0 3 0 5 1 1 6 1 0 1 0 Non-maskable interrupts
LOC: 99118 43626 176733 55708 828067 207665 115311 154475 78857 10037 61928 11351 Local timer interrupts
SPU: 0 0 0 0 0 0 0 0 0 0 0 0 Spurious interrupts
PMI: 1 0 3 0 5 1 1 6 1 0 1 0 Performance monitoring interrupts
IWI: 86064 28486 141932 40754 157189 94910 89143 116144 60778 5779 51049 5784 IRQ work interrupts
RTR: 0 0 0 0 0 0 0 0 0 0 0 0 APIC ICR read retries
RES: 310 314 5048 112 755 544 799 3192 584 60 481 99 Rescheduling interrupts
CAL: 20663 17009 19217 16776 19075 18387 15627 15893 17333 18026 18963 17581 Function call interrupts
TLB: 87 35 141 33 81 26 79 62 86 18 75 8 TLB shootdowns
TRM: 1 1 1 1 1 1 1 1 1 1 1 1 Thermal event interrupts
THR: 0 0 0 0 0 0 0 0 0 0 0 0 Threshold APIC interrupts
DFR: 0 0 0 0 0 0 0 0 0 0 0 0 Deferred Error APIC interrupts
MCE: 0 0 0 0 0 0 0 0 0 0 0 0 Machine check exceptions
MCP: 17 18 18 18 18 18 18 18 18 18 18 18 Machine check polls
ERR: 0
MIS: 0
PIN: 0 0 0 0 0 0 0 0 0 0 0 0 Posted-interrupt notification event
NPI: 0 0 0 0 0 0 0 0 0 0 0 0 Nested posted-interrupt event
PIW: 0 0 0 0 0 0 0 0 0 0 0 0 Posted-interrupt wakeup event
对于具体的网卡，可以通过
lspci -v -s 0000:01:00
来查看：
01:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
Subsystem: Hewlett-Packard Company InfiniBand FDR/Ethernet 10Gb/40Gb 2-port 544+FLR-QSFP Adapter
Flags: fast devsel, IRQ 16, IOMMU group 17
Memory at 82200000 (64-bit, non-prefetchable) [disabled] [size=1M]
Memory at 6166000000 (64-bit, prefetchable) [disabled] [size=32M]
Capabilities: [40] Power Management version 3
Capabilities: [48] Vital Product Data
Capabilities: [9c] MSI-X: Enable- Count=128 Masked-
Capabilities: [60] Express Endpoint, MSI 00
Capabilities: [c0] Vendor Specific Information: Len=18 <?>
Capabilities: [100] Alternative Routing-ID Interpretation (ARI)
Capabilities: [148] Device Serial Number c4-34-6b-ff-ff-df-e1-80
Capabilities: [108] Single Root I/O Virtualization (SR-IOV)
Capabilities: [154] Advanced Error Reporting
Capabilities: [18c] Secondary PCI Express
Kernel driver in use: vfio-pci
Kernel modules: mlx4_core
IRQ 16，后面发现另外一个网卡（hp561万兆电口网卡）同样使用 IRQ 16 从而造成冲突。
解决方案
删除造成 irq 冲突的硬件
可以用如下方法来删除造成冲突的硬件 ：
echo -n 1 > "/sys/devices/pci0000:00/0000:00:1b.0/remove"
通过 lspci 可以看到设备 device id ：
lspci
00:00.0 Host bridge: Intel Corporation Device 4650 (rev 05)
00:01.0 PCI bridge: Intel Corporation 12th Gen Core Processor PCI Express x16 Controller #1 (rev 05)
00:02.0 VGA compatible controller: Intel Corporation Alder Lake-S GT1 [UHD Graphics 730] (rev 0c)
00:0a.0 Signal processing controller: Intel Corporation Platform Monitoring Technology (rev 01)
00:14.0 USB controller: Intel Corporation Alder Lake-S PCH USB 3.2 Gen 2x2 XHCI Controller (rev 11)
00:14.2 RAM memory: Intel Corporation Alder Lake-S PCH Shared SRAM (rev 11)
00:15.0 Serial bus controller: Intel Corporation Alder Lake-S PCH Serial IO I2C Controller #0 (rev 11)
00:15.1 Serial bus controller: Intel Corporation Alder Lake-S PCH Serial IO I2C Controller #1 (rev 11)
00:15.2 Serial bus controller: Intel Corporation Alder Lake-S PCH Serial IO I2C Controller #2 (rev 11)
00:16.0 Communication controller: Intel Corporation Alder Lake-S PCH HECI Controller #1 (rev 11)
00:17.0 SATA controller: Intel Corporation Alder Lake-S PCH SATA Controller [AHCI Mode] (rev 11)
00:1a.0 PCI bridge: Intel Corporation Alder Lake-S PCH PCI Express Root Port #25 (rev 11)
00:1b.0 PCI bridge: Intel Corporation Device 7ac0 (rev 11)
00:1b.4 PCI bridge: Intel Corporation Device 7ac4 (rev 11)
00:1c.0 PCI bridge: Intel Corporation Alder Lake-S PCH PCI Express Root Port #1 (rev 11)
00:1c.1 PCI bridge: Intel Corporation Alder Lake-S PCH PCI Express Root Port #2 (rev 11)
00:1c.2 PCI bridge: Intel Corporation Device 7aba (rev 11)
00:1c.4 PCI bridge: Intel Corporation Alder Lake-S PCH PCI Express Root Port #5 (rev 11)
00:1d.0 PCI bridge: Intel Corporation Alder Lake-S PCH PCI Express Root Port #9 (rev 11)
00:1f.0 ISA bridge: Intel Corporation Z690 Chipset LPC/eSPI Controller (rev 11)
00:1f.3 Audio device: Intel Corporation Alder Lake-S HD Audio Controller (rev 11)
00:1f.4 SMBus: Intel Corporation Alder Lake-S PCH SMBus Controller (rev 11)
00:1f.5 Serial bus controller: Intel Corporation Alder Lake-S PCH SPI Controller (rev 11)
01:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
04:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 02)
07:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
08:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
09:00.0 Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro]
尝试过，如下设置，无效：
mkdir -p /sys/devices/pci0000:00/0000:01:00.0/
mkdir -p /sys/devices/pci0000:00/0000:04:00.0/
mkdir -p /sys/devices/pci0000:00/0000:08:00.0/
mkdir -p /sys/devices/pci0000:00/0000:09:00.0/
echo -n 1 > "/sys/devices/pci0000:00/0000:01:00.0/remove"
echo -n 1 > "/sys/devices/pci0000:00/0000:04:00.0/remove"
echo -n 1 > "/sys/devices/pci0000:00/0000:08:00.0/remove"
echo -n 1 > "/sys/devices/pci0000:00/0000:09:00.0/remove"
后记
这个问题第一次在 华硕 z690-p 主板上遇到，当时插了三块 hp544+ 和一块 hp561，结果 hp561 和 hp544+ 冲突了。
后来在 z87 主板上遇到类似的问题，IRQ 冲突严重到 pve 系统都不稳定。不得已只好放弃在这两个主板上插多块网卡的想法。