Comment by tensor

7 days ago

Apple has had a native hypervisor for some time now. This is probably a baked in clone of something like https://mac.getutm.app/ which provides the stuff on top of the hypervisor.

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tensor

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neuralkoi  7 days ago

In case you're wondering, the Hypervisor.framework C API is really neat and straightforward:

1. Creating and configuring a virtual machine:

    hv_vm_create(HV_VM_DEFAULT);

2. Allocating guest memory:

    void* memory = mmap(...);
    hv_vm_map(memory, guest_physical_address, size, HV_MEMORY_READ | HV_MEMORY_WRITE | HV_MEMORY_EXEC);

3. Creating virtual CPUs:

    hv_vcpu_create(&vcpu, HV_VCPU_DEFAULT);

4. Setting registers:

    hv_vcpu_write_register(vcpu, HV_X86_RIP, 0x1000); // Set instruction pointer
    hv_vcpu_write_register(vcpu, HV_X86_RSP, 0x8000); // Stack pointer

5. Running guest code:

    hv_vcpu_run(vcpu);

6. Handling VM exits:

    hv_vcpu_exit_reason_t reason;
    hv_vcpu_read_register(vcpu, HV_X86_EXIT_REASON, &reason);

conradev  7 days ago

One of the reasons OrbStack is so great is because they implement their own hypervisor: https://orbstack.dev/

Apple’s stack gives you low-level access to ARM virtualization, and from there Apple has high-level convenience frameworks on top. OrbStack implements all of the high-level code themselves.

watermelon0  7 days ago

Using a hypervisor means just running a Linux VM, like WSL2 does on Windows. There is nothing native about it.

Native Linux (and Docker) support would be something like WSL1, where Windows kernel implemented Linux syscalls.

  • petersellers  7 days ago

    Hyper-V is a type 1 hypervisor, so Linux and Windows are both running as virtual machines but they have direct access to hardware resources.

    It's possible that Apple has implemented a similar hypervisor here.

  • mdaniel  7 days ago

    Surely if Windows kernel can be taught to respond to those syscalls, XNU can be taught it even easier. But, AIUI the Windows kernel already had a concept of "personalities" from back when they were trying to integrate OS/2 so that zero-to-one for XNU could be a huge lift, not the syscalls part specifically

    • heavyset_go  6 days ago

      XNU similarly has a concept of "flavors" and uses FreeBSD code to provide the BSD flavor. Theoretically, either Linux code or a compatibility layer could be implemented in the kernel in a similar way. The former won't happen due to licensing.

    • kergonath  7 days ago

      > the Windows kernel already had a concept of "personalities" from back when they were trying to integrate OS/2 so that zero-to-one for XNU could be a huge lift, not the syscalls part specifically

      XNU is modular, with its BSD servers on top of Mach. I don’t see this as being a strong advantage of NT.

  • tensor  7 days ago

    > The Containerization framework enables developers to create, download, or run Linux container images directly on Mac. It's built on an open-source framework optimized for Apple Silicon and provides secure isolation between container images

    That's their phrasing, which suggests to me that it's just a virtualization system. Linux container images generally contain the kernel.