Re: [PATCH v5 0/6] Add vmnet.framework based network backend

[Jason Wang]

On Fri, Nov 12, 2021 at 5:14 PM Vladislav Yaroshchuk
<yaroshchuk2000@gmail.com> wrote:
>
> macOS provides networking API for VMs called 'vmnet.framework':
> https://developer.apple.com/documentation/vmnet
>
> We can provide its support as the new QEMU network backends which
> represent three different vmnet.framework interface usage modes:
>
>   * `vmnet-shared`:
>     allows the guest to communicate with other guests in shared mode and
>     also with external network (Internet) via NAT. Has (macOS-provided)
>     DHCP server; subnet mask and IP range can be configured;
>
>   * `vmnet-host`:
>     allows the guest to communicate with other guests in host mode.
>     By default has enabled DHCP as `vmnet-shared`, but providing
>     network unique id (uuid) can make `vmnet-host` interfaces isolated
>     from each other and also disables DHCP.
>
>   * `vmnet-bridged`:
>     bridges the guest with a physical network interface.
>
> This backends cannot work on macOS Catalina 10.15 cause we use
> vmnet.framework API provided only with macOS 11 and newer. Seems
> that it is not a problem, because QEMU guarantees to work on two most
> recent versions of macOS which now are Big Sur (11) and Monterey (12).
>
> Also, we have one inconvenient restriction: vmnet.framework interfaces
> can create only privileged user:
> `$ sudo qemu-system-x86_64 -nic vmnet-shared`
>
> Attempt of `vmnet-*` netdev creation being unprivileged user fails with
> vmnet's 'general failure'.
>
> This happens because vmnet.framework requires `com.apple.vm.networking`
> entitlement which is: "restricted to developers of virtualization software.
> To request this entitlement, contact your Apple representative." as Apple
> documentation says:
> https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_vm_networking

Do you know how multipass work? Looks like it uses vmnet without privileges.

Thanks

>
> One more note: we still have quite useful but not supported
> 'vmnet.framework' features as creating port forwarding rules, IPv6
> NAT prefix specifying and so on.
>
> Nevertheless, new backends work fine and tested within `qemu-system-x86-64`
> on macOS Bir Sur 11.5.2 host with such nic models:
>   * e1000-82545em
>   * virtio-net-pci
>   * vmxnet3
>
> The guests were:
>   * macOS 10.15.7
>   * Ubuntu Bionic (server cloudimg)
>
>
> This series partially reuses patches by Phillip Tennen:
> https://patchew.org/QEMU/20210218134947.1860-1-phillip.ennen@gmail.com/
> So I included his signed-off line into one of the commit messages and
> also here.
>
> v1 -> v2:
>  Since v1 minor typos were fixed, patches rebased onto latest master,
>  redundant changes removed (small commits squashed)
>
> v2 -> v3:
>  - QAPI style fixes
>  - Typos fixes in comments
>  - `#include`'s updated to be in sync with recent master
> v3 -> v4:
>  - Support vmnet interfaces isolation feature
>  - Support vmnet-host network uuid setting feature
>  - Refactored sources a bit
> v4 -> v5:
>  - Missed 6.2 boat, now 7.0 candidate
>  - Fix qapi netdev descriptions and styles
>    (@subnetmask -> @subnet-mask)
>  - Support vmnet-shared IPv6 prefix setting feature
>
> Signed-off-by: Phillip Tennen <phillip@axleos.com>
> Signed-off-by: Vladislav Yaroshchuk <yaroshchuk2000@gmail.com>
>
> Vladislav Yaroshchuk (6):
>   net/vmnet: add vmnet dependency and customizable option
>   net/vmnet: add vmnet backends to qapi/net
>   net/vmnet: implement shared mode (vmnet-shared)
>   net/vmnet: implement host mode (vmnet-host)
>   net/vmnet: implement bridged mode (vmnet-bridged)
>   net/vmnet: update qemu-options.hx
>
>  meson.build                   |   4 +
>  meson_options.txt             |   2 +
>  net/clients.h                 |  11 ++
>  net/meson.build               |   7 +
>  net/net.c                     |  10 ++
>  net/vmnet-bridged.m           | 111 ++++++++++++
>  net/vmnet-common.m            | 325 ++++++++++++++++++++++++++++++++++
>  net/vmnet-host.c              | 111 ++++++++++++
>  net/vmnet-shared.c            |  92 ++++++++++
>  net/vmnet_int.h               |  48 +++++
>  qapi/net.json                 | 127 ++++++++++++-
>  qemu-options.hx               |  25 +++
>  scripts/meson-buildoptions.sh |   3 +
>  13 files changed, 874 insertions(+), 2 deletions(-)
>  create mode 100644 net/vmnet-bridged.m
>  create mode 100644 net/vmnet-common.m
>  create mode 100644 net/vmnet-host.c
>  create mode 100644 net/vmnet-shared.c
>  create mode 100644 net/vmnet_int.h
>
> --
> 2.23.0
>