By default, when you install a Juniper vMX device the physical interfaces will all be named “ge-0/0/*” and the output from show interface ge-0/0/X will show the speed as 1G. If you are using SR-IOV with 10G/100G NIC’s this can be a bit confusing. According to the Juniper docs this is only for display purposes and it is not enforced, the impact is only if you use schedulers (QoS):
The default port speed values for the interface types are 1 Gbps (ge), 10 Gbps (xe), and 100 Gbps (et). If you do not enable schedulers, the speed is only for display purposes and is not enforced. If you enable schedulers, the transmit rate of the port is limited to the speed unless it is overridden by the shaping rate in the CoS configuration.
To fix this you can set the interface-type option on the PIC:
set chassis fpc 0 pic 0 interface-type xe
Changing this setting will cause all interfaces to be renamed to “xe-0/0/*” on the FPC. You will need to rename any existing interfaces in the interface configuration as well:
rename interface ge-0/0/0 to xe-0/0/0 rename interface ge-0/0/1 to xe-0/0/1 rename interface ge-0/0/2 to xe-0/0/2 ...