Read Hyper-V key-value pair data on Linux guest

hvkvp.py

# Inspired by https://github.com/ejsiron/hvkvp
# explanation of format https://www.altaro.com/hyper-v/key-value-pair-data-exchange-3-linux/

# pool_3 host->guest (read-only)
with open("/var/lib/hyperv/.kvp_pool_3", "r") as f:
  data = f.read()

# Each k, v is a nul terminated string. k is 512 bytes, v 2048 bytes
# so 2560 bytes is a single item
n = 2560

pairs = {
  # It looks like the nul terminated strings may have non nul data so stop reading when
  # first nul byte is found after the data
  c[0:c[0:512].find("\x00")].replace("\x00",""): c[512:512+c[512:].find("\x00")].replace("\x00","")
  for c in [data[i:i+n] for i in range(0, len(data), n)]
}

print(pairs)

{
  "HostName": "HYPERV01",
  "HostingSystemEditionId": "42",
  "HostingSystemOsMajor": "10",
  "HostingSystemOsMinor": "0",
  "HostingSystemProcessorArchitecture": "9",
  "HostingSystemSpMajor": "0",
  "HostingSystemSpMinor": "0",
  "PhysicalHostName": "HYPERV01",
  "PhysicalHostNameFullyQualified": "HYPERV01",
  "VirtualMachineId": "8049526A-4F67-46C1-B144-DFED29F9F432",
  "VirtualMachineName": "vmcent74docker",
  "HostingSystemNestedLevel": "0",
  "HostingSystemProcessorIdleStateMax": "0",
  "HostingSystemProcessorThrottleMax": "100",
  "HostingSystemProcessorThrottleMin": "5",
  "VirtualMachineDynamicMemoryBalancingEnabled": "1"
}

Related reading about Hyper-V socket services
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/make-integration-service
https://stackoverflow.com/questions/60696166/using-the-hyper-v-sockets-between-windows-host-and-linux-guest