After upgrading Proxmox to 4.1, pfSense launched as a virtual machine began to slow down. How to fix?

Question

linux

After upgrading Proxmox from version 3.4 to 4.1, pfSense 2.1.5-RELEASE (amd64) started as a virtual machine began to slow down.
Virtio network card drivers.
Document https://doc.pfsense.org/index.php/Low_Throughput_T...
Examined Host has errors on interfaces to which Pfsense
vmbr3 is bound Link encap:Ethernet HWaddr
inet6 addr: Scope:Link
UP BROADCAST RUNNING MULTICAST MTU :1500 Metric:1
RX packets:145023 errors:0 dropped:4535 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:8312411 (7.9 MiB )TX bytes:648 (648.0 B)
There are no errors on the Pfsense interfaces. Shaper, squid is not installed. Firewall on Proxmox is disabled.
I look forward to your advice. I would be grateful for any ideas.

Answer 1

Solution found here:
https://pve.proxmox.com/wiki/PfSense_Guest_Notes
Namely:
Enter the web GUI and go in System > Advanced > Networking and flag Disable hardware checksum offload. If you don't do it layer3 traffic from lan to wan will not work, or will be really slow (but traffic to/from the firewall will work fine).