[SOLVED] Guest CPU way too slow

[telesteven]

Hey
I installed a guest linux and configured it with a 10 GbE network connection.
When doing an iperf3 to the guest I see a stable 10 Gbit/s connection

[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  10.9 GBytes  9.38 Gbits/sec    0             sender
[  5]   0.00-10.03  sec  10.9 GBytes  9.35 Gbits/sec                  receiver

When I now try to scp data to the guest I barely get 40 MB/s as the sshd process ist at 100% on the guest.
Transfering the data via scp to the proxmost host works with around 600 MB/s

The guest is configured with 64 CPU cores.

When using netcat to transfer the data to the guest I also receive rates >600MB/s

Is there something to be considered when configuring the CPU for the guest?



lscpu:

Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              64
On-line CPU(s) list: 0-63
Thread(s) per core:  1
Core(s) per socket:  32
Socket(s):           2
NUMA node(s):        1
Vendor ID:           GenuineIntel
BIOS Vendor ID:      QEMU
CPU family:          15
Model:               6
Model name:          Common KVM processor
BIOS Model name:     pc-i440fx-6.0
Stepping:            1
CPU MHz:             2992.966
BogoMIPS:            5985.93
Hypervisor vendor:   KVM
Virtualization type: full
L1d cache:           32K
L1i cache:           32K
L2 cache:            4096K
L3 cache:            16384K
NUMA node0 CPU(s):   0-63
Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx lm constant_tsc nopl xtopology cpuid tsc_known_freq pni cx16 x2apic hypervisor lahf_lm cpuid_fault pti

 

[Matthias.]

try cpu type host

 

[ITT]

This is normal, your virtual CPU-Type is KVM.
So no AES/SSL offload/handling etc is possible.
Change it to "host".

 

[telesteven]

Indeed, after a setting the CPU-Type to host everything seems way better (300MB/s+)
Many thanks!