Fix proxmox mem hotplug, improve virtual hw support

[ioctl2]

Main changes:

• Enables memory hot plug and hot remove in Proxmox VE (tested in version 7.2-7)
• Fixes guest incorrect memory detection in Proxmox when memory hot plug is enabled for the VM. Without this fix, enabling mem hot plug would result in <1G of memory being seen by the guest, regardless of the amount (>1G) allocated for the VM.
• Adds missing VirtualBox guest additions (CONFIG_VBOXGUEST=m). You will now see memory utilization in VirtualBox'es Performance Monitor.
• Adds missing symbols for PCI/PCIe hot plug support on hypervisors where this feature is present (ACPI, SHPC, and native PCIe).
• Enables support for virtio crypto device.

Tests performed:

[CPU hot plug was working previously; I tested it again to rule out unexpected behaviour.]

Proxmox VE 7.2-7:

• MEM hotplug:
  -- ovmf+qxl+i440fx [acpi=y, kvm=y, qemu-guest=y] -> plug ok, remove ok
  -- ovmf+qxl+q35 [acpi=y, kvm=y, qemu-guest=y] -> plug ok, remove ok (not always possible when allotted mem <~4G)
• CPU hotplug:
  -- ovmf+qxl+i440fx [acpi=y, kvm=y, qemu-guest=y] -> plug ok, remove ok
  -- ovmf+qxl+q35 [acpi=y, kvm=y, qemu-guest=y] -> plug ok, remove ok

VMWare Workstation 16.2.4 build-20089737:

• MEM hotplug - hw compatibility set to 16.2.x - (with mem.hotadd = "TRUE" in the vmx): hot plug ok, hot unplug unsupported.
• CPU hotplug - hw compatibility set to 16.2.x - (with vcpu.hotadd = "TRUE" in the vmx): hot plug ok, hot unplug unsupported.

Oracle VirtualBox Version 6.1.36 r152435 (Qt5.6.2):

• Guest additions reported as 6.0.0 r127566] (when compiled on 2022SEP17 from dev branch)
• MEM hot plug: Appears to still be unsupported by VirtualBox.
• CPU hot plug:
  -- piix3/kvm/ee:vt-x: works, unplug doesn't
  -- ICH9/kvm/ee:vt-x: plug works, unplug doens't

VMWare ESXi 7.0 Update 3:

• Virtual HW compatibility left as 'ESXi 5.5 virtual machine', OS set to rhel7, hotplug enabled for vm ->
  -- CPU hot plug ok, hot remove unsupported
• Virtual HW compatibility left as 'ESXi 5.5 virtual machine', OS set to rhel7, hotplug enabled for vm ->
  -- MEM hot plug ok, hot remove unsupported

Untested / TODO:

QEMU - not tested - TODO - looking for community testers.
Hyper-V - not tested - TODO - looking for community testers.
-- I have only tested the changes on a Windows 10 21H2 host. The VMWare ESXi instance was virtualized inside VMWare Workstation.

This is my first PR for this project, so please do let me know what I can improve in future PRs. This took some research, and I'm not sure how much is expected in these PRs by way of reference and details. I'm happy to answer any questions you may have. And of course, happy to make changes if required.

[homeassistant]

Hi @ioctl2,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[agners]

CPU and Memory hot-plug and removal seems to work with libvirt/qemu. Virtual Machine Manager supports to change memory from the UI, however, for CPU I had to use the console:

virsh # setvcpus --count 2 HomeAssistant

I did use this vcpus section in the domain XML

  <vcpus>
    <vcpu id="0" enabled="yes" hotpluggable="no"/>
    <vcpu id="1" enabled="yes" hotpluggable="yes"/>
    <vcpu id="2" enabled="no" hotpluggable="yes"/>
    <vcpu id="3" enabled="no" hotpluggable="yes"/>
  </vcpus>