Re: Guest shutdown hang host machine.

[David Hill <dhill@xxxxxxxxxx>]

I'm having a similar issue these days... host machine networking hangs 
for a little while when shutting down guests but connectivity resumes 
once the guests are down.

On 2019-01-10 7:11 a.m., Alex K wrote:
> Good day!
>
> We are using Ubuntu + KVM (via qemu and libvirt) and we've run into some difficulties.
> Host OS:
> Distributor ID: Ubuntu
> Description: Ubuntu 18.04.1 LTS
> Release: 18.04
> Codename: bionic
> Spec server:
> Supermicro SYS‌-5017GR-TF
> CPU 1‌*Xeon E5-2690v2
> RAM 6‌*8GB ECC
> SSD 2‌*1TB Samsung EVO860
> GPU 2‌*GTX1070
> Network HP523SFP 10G
> PSU 1200W
> VM guest:
> vCPU 8 threads
> RAM 16GB
> GPU 1*GTX1070 (using vfio-pci)
> netowrking - vepa with macvtap
>
> When the guest is receiving 'virsh destroy $vmname' command, the host machine hangs with
> "NMI Watchdog BUG: soft lockup - CPU # 2 stuck for 22s".
>
> How we tried to fix this issue:
>
>      Update bios to latest version
>      Updating to previous distro version, using alternatives (centos, debian)
>      Replace hardware components (CPU, RAM, Network Card, HDD and SSD)
>      Change some BIOS settings:
>
>      Tried adjusting:
>      PERR# Generation
>      SERR# Generation
>      Above 4G Decoding
>      Cpu max performance
>      Disabling internal NIC
>      Removing excessive boot devices
>      Power technology: various parameters
>      enegry/performace bias: various parameters
>      Pcie port: gen2 and gen3.
>
> Problems occur only when guests are going down and new ones are created.
>
> Attached files (console screenshots)
>
> https://drive.google.com/open?id=1AHCabWEy88A9pBK26D40LXFMWZMehejX
> https://drive.google.com/open?id=17VvCPVSWOJjEm-7nF9mrGNmd7vYNtR9x
> https://drive.google.com/open?id=1RBkBcCnTCRLGDwf59Lh8s0yeGvCiYhw7
>
>
>
> Regards, Alex.