Hi,
I run OpenBSD (snapshots) in a KVM+QEMU VM on Debian 9 and use it over
SSH. Those SSH sessions stall almost without fail when there's a lot of
output.
Repro (or at least my set up):
1. Create a KVM+QMEU VM on Linux with virt-manager. I assigned two
cores and otherwise used defaults.
2. Install an OpenBSD snapshot.
3. In an SSH session, execute 'find /' until hang. I suspect other
large network transfers may result in the same.
Symptoms:
- SSH session stalls with no output, no echo, and no response to ^C.
- New communication (SSH, ping) cannot be established: "no route to
host"
- The serial console outputs "re0: watchdog timeout"
- From the serial code, pinging the host yields "ping: sendmsg: No
buffer space available"
Workaround:
'ifconfig re0 down; ifconfig re0 up' and a little patience fixes it.
Below, the VM's dmesg and its libvirt XML dump. After seeing the NFS
messages I unmounted the shares but the behaviour was the same.
Sijmen
OpenBSD 6.4-current (GENERIC.MP) #689: Fri Feb 8 00:40:27 MST 2019
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 2130575360 (2031MB)
avail mem = 2056372224 (1961MB)
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.8 @ 0xf6880 (10 entries)
bios0: vendor SeaBIOS version "1.10.2-1" date 04/01/2014
bios0: QEMU Standard PC (i440FX + PIIX, 1996)
acpi0 at bios0: rev 0
acpi0: sleep states S5
acpi0: tables DSDT FACP APIC
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel Core Processor (Skylake), 3312.53 MHz, 06-5e-03
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SSE3,PCLMUL,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,RDTSCP,LONG,LAHF,ABM,3DNOWP,FSGSBASE,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,ARAT,XSAVEOPT,XSAVEC,XGETBV1,MELTDOWN
cpu0: 64KB 64b/line 2-way I-cache, 64KB 64b/line 2-way D-cache, 512KB 64b/line
16-way L2 cache
cpu0: ITLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu0: DTLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu0: smt 0, core 0, package 0
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 1000MHz
cpu1 at mainbus0: apid 1 (application processor)
cpu1: Intel Core Processor (Skylake), 3312.09 MHz, 06-5e-03
cpu1:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SSE3,PCLMUL,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,RDTSCP,LONG,LAHF,ABM,3DNOWP,FSGSBASE,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,ARAT,XSAVEOPT,XSAVEC,XGETBV1,MELTDOWN
cpu1: 64KB 64b/line 2-way I-cache, 64KB 64b/line 2-way D-cache, 512KB 64b/line
16-way L2 cache
cpu1: ITLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu1: DTLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu1: smt 0, core 0, package 1
ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 11, 24 pins
acpiprt0 at acpi0: bus 0 (PCI0)
acpicpu0 at acpi0: C1(@1 halt!)
acpicpu1 at acpi0: C1(@1 halt!)
"ACPI0006" at acpi0 not configured
acpipci0 at acpi0 PCI0: _OSC failed
acpicmos0 at acpi0
"PNP0A06" at acpi0 not configured
"PNP0A06" at acpi0 not configured
"PNP0A06" at acpi0 not configured
"QEMU0002" at acpi0 not configured
"ACPI0010" at acpi0 not configured
pvbus0 at mainbus0: KVM
pvclock0 at pvbus0
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel 82441FX" rev 0x02
pcib0 at pci0 dev 1 function 0 "Intel 82371SB ISA" rev 0x00
pciide0 at pci0 dev 1 function 1 "Intel 82371SB IDE" rev 0x00: DMA, channel 0
wired to compatibility, channel 1 wired to compatibility
wd0 at pciide0 channel 0 drive 0: <QEMU HARDDISK>
wd0: 16-sector PIO, LBA48, 20480MB, 41943040 sectors
atapiscsi0 at pciide0 channel 0 drive 1
scsibus1 at atapiscsi0: 2 targets
cd0 at scsibus1 targ 0 lun 0: <QEMU, QEMU DVD-ROM, 2.5+> ATAPI 5/cdrom removable
wd0(pciide0:0:0): using PIO mode 4, DMA mode 2
cd0(pciide0:0:1): using PIO mode 4, DMA mode 2
pciide0: channel 1 disabled (no drives)
piixpm0 at pci0 dev 1 function 3 "Intel 82371AB Power" rev 0x03: apic 0 int 9
iic0 at piixpm0
vga1 at pci0 dev 2 function 0 "Red Hat QXL Video" rev 0x04
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
re0 at pci0 dev 3 function 0 "Realtek 8139" rev 0x20: RTL8139C+ (0x7480), apic
0 int 11, address 52:54:00:35:78:47
rlphy0 at re0 phy 0: RTL internal PHY
azalia0 at pci0 dev 4 function 0 "Intel 82801FB HD Audio" rev 0x01: apic 0 int
11
azalia0: No codecs found
uhci0 at pci0 dev 5 function 0 "Intel 82801I USB" rev 0x03: apic 0 int 10
uhci1 at pci0 dev 5 function 1 "Intel 82801I USB" rev 0x03: apic 0 int 10
uhci2 at pci0 dev 5 function 2 "Intel 82801I USB" rev 0x03: apic 0 int 11
ehci0 at pci0 dev 5 function 7 "Intel 82801I USB" rev 0x03: apic 0 int 11
usb0 at ehci0: USB revision 2.0
uhub0 at usb0 configuration 1 interface 0 "Intel EHCI root hub" rev 2.00/1.00
addr 1
virtio0 at pci0 dev 6 function 0 "Qumranet Virtio Console" rev 0x00
virtio0: no matching child driver; not configured
virtio1 at pci0 dev 7 function 0 "Qumranet Virtio Memory Balloon" rev 0x00
viomb0 at virtio1
virtio1: apic 0 int 11
isa0 at pcib0
isadma0 at isa0
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
com0: console
pckbc0 at isa0 port 0x60/5 irq 1 irq 12
pckbd0 at pckbc0 (kbd slot)
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pms0 at pckbc0 (aux slot)
wsmouse0 at pms0 mux 0
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
usb1 at uhci0: USB revision 1.0
uhub1 at usb1 configuration 1 interface 0 "Intel UHCI root hub" rev 1.00/1.00
addr 1
usb2 at uhci1: USB revision 1.0
uhub2 at usb2 configuration 1 interface 0 "Intel UHCI root hub" rev 1.00/1.00
addr 1
usb3 at uhci2: USB revision 1.0
uhub3 at usb3 configuration 1 interface 0 "Intel UHCI root hub" rev 1.00/1.00
addr 1
vscsi0 at root
scsibus2 at vscsi0: 256 targets
softraid0 at root
scsibus3 at softraid0: 256 targets
root on wd0a (352b991b8750a90d.a) swap on wd0b dump on wd0b
fd0 at fdc0 drive 1: density unknown
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: not responding
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: is alive again
nfs server sijmens-pc:/mnt/data/oports: not responding
re0: watchdog timeout
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: is alive again
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: not responding
nfs server sijmens-pc:/mnt/data/oports: is alive again
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: not responding
nfs server sijmens-pc:/mnt/data/oports: is alive again
re0: watchdog timeout
nfs server sijmens-pc:/mnt/data/oports: not responding
nfs server sijmens-pc:/mnt/data/oports: is alive again
re0: watchdog timeout
re0: watchdog timeout
re0: watchdog timeout
nfs server sijmens-pc:/home/sjmulder/code: not responding
re0: watchdog timeout
nfs server sijmens-pc:/home/sjmulder/code: is alive again
<domain type='kvm' id='1'>
<name>openbsd</name>
<uuid>ba2ff785-3780-4dab-bd52-c7312feee73e</uuid>
<memory unit='KiB'>2097152</memory>
<currentMemory unit='KiB'>2097152</currentMemory>
<vcpu placement='static'>2</vcpu>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64' machine='pc-i440fx-2.8'>hvm</type>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
<vmport state='off'/>
</features>
<cpu mode='custom' match='exact'>
<model fallback='forbid'>Skylake-Client</model>
</cpu>
<clock offset='utc'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<pm>
<suspend-to-mem enabled='no'/>
<suspend-to-disk enabled='no'/>
</pm>
<devices>
<emulator>/usr/bin/kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/mnt/data/virt/openbsd.qcow2'/>
<backingStore/>
<target dev='hda' bus='ide'/>
<alias name='ide0-0-0'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<backingStore/>
<target dev='hdb' bus='ide'/>
<readonly/>
<alias name='ide0-0-1'/>
<address type='drive' controller='0' bus='0' target='0' unit='1'/>
</disk>
<controller type='usb' index='0' model='ich9-ehci1'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05'
function='0x7'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci1'>
<alias name='usb'/>
<master startport='0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'
multifunction='on'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci2'>
<alias name='usb'/>
<master startport='2'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05'
function='0x1'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci3'>
<alias name='usb'/>
<master startport='4'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05'
function='0x2'/>
</controller>
<controller type='pci' index='0' model='pci-root'>
<alias name='pci.0'/>
</controller>
<controller type='ide' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01'
function='0x1'/>
</controller>
<controller type='virtio-serial' index='0'>
<alias name='virtio-serial0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</controller>
<interface type='network'>
<mac address='52:54:00:35:78:47'/>
<source network='default' bridge='virbr0'/>
<target dev='vnet0'/>
<model type='rtl8139'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03'
function='0x0'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/4'/>
<target port='0'/>
<alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/4'>
<source path='/dev/pts/4'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
<channel type='spicevmc'>
<target type='virtio' name='com.redhat.spice.0' state='disconnected'/>
<alias name='channel0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
<input type='mouse' bus='ps2'>
<alias name='input0'/>
</input>
<input type='keyboard' bus='ps2'>
<alias name='input1'/>
</input>
<graphics type='spice' port='5900' autoport='yes' listen='127.0.0.1'>
<listen type='address' address='127.0.0.1'/>
<image compression='off'/>
</graphics>
<sound model='ich6'>
<alias name='sound0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04'
function='0x0'/>
</sound>
<video>
<model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1'
primary='yes'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02'
function='0x0'/>
</video>
<redirdev bus='usb' type='spicevmc'>
<alias name='redir0'/>
<address type='usb' bus='0' port='1'/>
</redirdev>
<redirdev bus='usb' type='spicevmc'>
<alias name='redir1'/>
<address type='usb' bus='0' port='2'/>
</redirdev>
<memballoon model='virtio'>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x07'
function='0x0'/>
</memballoon>
</devices>
<seclabel type='none' model='none'/>
<seclabel type='dynamic' model='dac' relabel='yes'>
<label>+64055:+64055</label>
<imagelabel>+64055:+64055</imagelabel>
</seclabel>
</domain>
