The vmnet API allows virtual machines to read and write packets on guest operating systems.

Posts under vmnet tag

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Programmatic IP Discovery for VZVirtualMachine in an App Store Sandbox
Hi everyone, I am developing a macOS virtualization manager (VirtualProg) using the Virtualization.framework. The application is distributed via the Mac App Store, so it operates strictly within the App Store Sandbox. I am looking for a reliable, programmatic way to discover the IP address assigned to a guest (both macOS and Linux). Is there a recommended "Sandbox-safe" API or pattern within the Virtualization framework—or a lower-level networking entitlement—that allows a host application to retrieve the guest's assigned IP address? Ideally, I am looking for a solution that does not require the user to manually install a non-sandboxed helper tool. Thanks in advance for any insights or guidance!
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17h
Port forwarding with VZVmnetNetworkDeviceAttachment
I have the following code for port forwarding in mac os virtualization var ipAddr = in_addr() // 1. Convert String to in_addr inet_pton(AF_INET, guestIP, &ipAddr) let status = vmnet_network_configuration_add_port_forwarding_rule( config, UInt8(IPPROTO_TCP), // TCP protocol sa_family_t(AF_INET), // address family guestPort, // internal port (guest) externalPort, // external port (host) &ipAddr // internal address (guest IP) ) if status == .VMNET_SUCCESS { print("✅ Port Forwarding set: Mac:\(externalPort) -> VM(\(guestIP)):\(guestPort)") } else { print("❌ Port Forwarding failed for \(guestIP): \(status.rawValue)") } It is returning success but when i test it it does not work. Is there anything i am doing wrong? Please help me also in fixing this problem. Note: The app runs in sandbox i tried without sandboxing and it does not work either. Please refer to this link https://developer.apple.com/forums/thread/822025?login=true&page=1#884236022 how i am creating the VZVmnetNetworkDeviceAttachment
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New Virtualization features in macOS Tahoe
I'm pleased to share some significant updates that have recently been released for our Hypervisor and Virtualization frameworks. We've focused on enhancing efficiency, expanding capabilities, and addressing common developer needs. I believe these will be valuable for many of you. Here’s a look at what’s new: Hypervisor Updates We've introduced support for configuring the intermediate physical address (IPA) memory granularity of a VM. This allows for more granular memory mappings, enabling granularity sizes down to 4KB. This is particularly useful for certain specialized device drivers requiring finer memory control. Virtualization Framework Updates More Efficient VM Image Storage with ASIF: We've integrated support for the Apple Sparse Image Format (ASIF). This results in a smaller disk footprint and optimized transfer for VM disk images when using VZDiskImageStorageDeviceAttachment, improving storage efficiency. Custom Network Topologies with vmnet: We've added support for vmnet custom network topologies. This enables more flexible VM-to-VM communication based on logical networks with customized configurations, useful for complex testing or development environments. See VZVmnetNetworkDeviceAttachment to get started. Simplified VM Queue Discovery: It's now easier to discover a VM’s on-process thanks to a new property on VZVirtualMachine. This should aid in development and debugging when interacting directly with the VM's queue. These are some of the key highlights of the first beta, and I'm looking forward to seeing how these improvements will be utilized. I encourage you to explore the documentation for full details on these features.
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646
Jan ’26
restore root file with tmutil
I have a simple impossible task, to restore /var/root/Library/Application Support/multipassd/qemu/vault/instances/gcc-cobol/ubuntu-22.04-server-cloudimg-arm64.img as of 8:02 Saturday morning. Because /var/root is owned by, well, root, the usual techniques don't work. This is a VM image hosted by qemu via Canonical's Multipass. ISTM the strategy would be to first mount the NAS filesystem and then use tmutil(8) to list the backups and recover the file. But $ sudo mount -v -o rdonly -t smb //nasa.local/TimeMachine /usr/local/mnt/ mount: exec /Library/Filesystems/smb.fs/Contents/Resources/mount_smb for /usr/local/mnt: No such file or directory mount: /usr/local/mnt failed with 72 Must I defeat SIP to do this?
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183
Jul ’25
virtio_net_hdr recommendations
Hey there! I’ve got some exciting news about Apple’s virtio_net_hdr implementation on macOS 15.4. It’s making communication a lot smoother, with a noticeable improvement! Now, I’d love to hear your thoughts on a couple of things. First, how do you think we can validate the populated values? And secondly, should we consider reusing populated values for the other endpoint, like the ‘flags’ field? Your insights would be invaluable!
3
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224
Apr ’25
Programmatic IP Discovery for VZVirtualMachine in an App Store Sandbox
Hi everyone, I am developing a macOS virtualization manager (VirtualProg) using the Virtualization.framework. The application is distributed via the Mac App Store, so it operates strictly within the App Store Sandbox. I am looking for a reliable, programmatic way to discover the IP address assigned to a guest (both macOS and Linux). Is there a recommended "Sandbox-safe" API or pattern within the Virtualization framework—or a lower-level networking entitlement—that allows a host application to retrieve the guest's assigned IP address? Ideally, I am looking for a solution that does not require the user to manually install a non-sandboxed helper tool. Thanks in advance for any insights or guidance!
Replies
16
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0
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307
Activity
17h
Port forwarding with VZVmnetNetworkDeviceAttachment
I have the following code for port forwarding in mac os virtualization var ipAddr = in_addr() // 1. Convert String to in_addr inet_pton(AF_INET, guestIP, &ipAddr) let status = vmnet_network_configuration_add_port_forwarding_rule( config, UInt8(IPPROTO_TCP), // TCP protocol sa_family_t(AF_INET), // address family guestPort, // internal port (guest) externalPort, // external port (host) &ipAddr // internal address (guest IP) ) if status == .VMNET_SUCCESS { print("✅ Port Forwarding set: Mac:\(externalPort) -> VM(\(guestIP)):\(guestPort)") } else { print("❌ Port Forwarding failed for \(guestIP): \(status.rawValue)") } It is returning success but when i test it it does not work. Is there anything i am doing wrong? Please help me also in fixing this problem. Note: The app runs in sandbox i tried without sandboxing and it does not work either. Please refer to this link https://developer.apple.com/forums/thread/822025?login=true&page=1#884236022 how i am creating the VZVmnetNetworkDeviceAttachment
Replies
7
Boosts
0
Views
110
Activity
17h
New Virtualization features in macOS Tahoe
I'm pleased to share some significant updates that have recently been released for our Hypervisor and Virtualization frameworks. We've focused on enhancing efficiency, expanding capabilities, and addressing common developer needs. I believe these will be valuable for many of you. Here’s a look at what’s new: Hypervisor Updates We've introduced support for configuring the intermediate physical address (IPA) memory granularity of a VM. This allows for more granular memory mappings, enabling granularity sizes down to 4KB. This is particularly useful for certain specialized device drivers requiring finer memory control. Virtualization Framework Updates More Efficient VM Image Storage with ASIF: We've integrated support for the Apple Sparse Image Format (ASIF). This results in a smaller disk footprint and optimized transfer for VM disk images when using VZDiskImageStorageDeviceAttachment, improving storage efficiency. Custom Network Topologies with vmnet: We've added support for vmnet custom network topologies. This enables more flexible VM-to-VM communication based on logical networks with customized configurations, useful for complex testing or development environments. See VZVmnetNetworkDeviceAttachment to get started. Simplified VM Queue Discovery: It's now easier to discover a VM’s on-process thanks to a new property on VZVirtualMachine. This should aid in development and debugging when interacting directly with the VM's queue. These are some of the key highlights of the first beta, and I'm looking forward to seeing how these improvements will be utilized. I encourage you to explore the documentation for full details on these features.
Replies
3
Boosts
3
Views
646
Activity
Jan ’26
restore root file with tmutil
I have a simple impossible task, to restore /var/root/Library/Application Support/multipassd/qemu/vault/instances/gcc-cobol/ubuntu-22.04-server-cloudimg-arm64.img as of 8:02 Saturday morning. Because /var/root is owned by, well, root, the usual techniques don't work. This is a VM image hosted by qemu via Canonical's Multipass. ISTM the strategy would be to first mount the NAS filesystem and then use tmutil(8) to list the backups and recover the file. But $ sudo mount -v -o rdonly -t smb //nasa.local/TimeMachine /usr/local/mnt/ mount: exec /Library/Filesystems/smb.fs/Contents/Resources/mount_smb for /usr/local/mnt: No such file or directory mount: /usr/local/mnt failed with 72 Must I defeat SIP to do this?
Replies
2
Boosts
0
Views
183
Activity
Jul ’25
virtio_net_hdr recommendations
Hey there! I’ve got some exciting news about Apple’s virtio_net_hdr implementation on macOS 15.4. It’s making communication a lot smoother, with a noticeable improvement! Now, I’d love to hear your thoughts on a couple of things. First, how do you think we can validate the populated values? And secondly, should we consider reusing populated values for the other endpoint, like the ‘flags’ field? Your insights would be invaluable!
Replies
3
Boosts
0
Views
224
Activity
Apr ’25