4 ms·

I believe the most promising route is to not try to do passthrough but to use a "virtual" gpu, aka a paravirtualized device. Thanks to the contributions of an o

by luzeal 5y ago

I believe the most promising route is to not try to do passthrough but to use a "virtual" gpu, aka a paravirtualized device. Thanks to the contributions of an open-source developer*, virtio-gpu has been ported to macOS (it already works on Linux but not on Windows and soon it will be on macOS). Apple is also reportedly working on bringing better support for macOS virtualized environments [2]. It means that users will be able to create any number of macOS instances with 3D acceleration, without having to care about trying to do complicated things (mediated devices or single-gpu passthrough or pci-passthrough of a second GPU). As of now, the performance hit is high (more than 50%), but it will certainly improve over time, and many users might already find it acceptable (= people NOT playing recent video games). Icing on the cake, thanks to the EGL-headless display (which is independent of virtio-gpu) and VNC, it is possible to connect to these instances remotely. Shameless plug: I am working on Phyllome OS [3], a Fedora Remix with the goal to include the necessary plumbing to ease advanced virtualization techniques for end-users, and to offer curated virtual machine models. I currently only use virtual machines as desktop machines, including locally, and even my poor x230 laptop can do it. I keep the host operating system intact (Phyllome OS), and use VMs as desktop machines. It has drawbacks (difficult USB access; displays models that were not designed for local use; sound support), but I firmly believe it will get better over time and, perhaps, one day, end-users will be able to easily deploy any modern OS on any modern hardware... [1] Sorry, I could not find the link to the repository [2] https://passthroughpo.st/mac-os-adds-early-support-for-virtio-qemu/ https://passthroughpo.st/mac-os-adds-early-support-for-virti... [3] https://phyllo.me/ https://phyllo.me/ [edit] Delete mention of KVM/QEMU

S5yDyAk3XoQH5 5y ago
Wow that's very surprising apple is trying to give better support for virtual environments instead of worse.. Do you know if they're allowing their iOS dev tools to run in there so you don't have to buy a mac anymore?
- macinjosh 5y ago
  I have been developing a toy iOS/macOS app running macOS with this. I am able to login with my dev program credentials and do everything I need. I haven't tried submitting anything to the store.
  - mrkstu 5y ago
    So the virtualization hooks aren't just in MacOS? I could compile your app on my M1 iPad and run full MacOS virtually?
    - saagarjha 5y ago
      No, Apple doesn't expose virtualization on iPad.
- dev_tty01 5y ago
  Apple is adding better support for virtual environments running on the Mac. Not virtual macs running on other machines. That is all coming from the community.
gary17the 5y ago
> without having to care about trying to do complicated things ([...] pci-passthrough of a second GPU) Actually, GPU passthrough is quite simple: configure host Linux to assign a virtual driver to a secondary GPU on boot and configure QEMU to use that driver on guest boot[1]. If you buy a GPU that is natively supported by macOS (e.g., Sapphire Radeon RX 580 Pulse 4GB), you get 99% performance and 100% stability of a native Mac (not a single macOS/QEMU crash in years for me). Moreover, if you configure your QEMU mouse/keyboard to use evdev[2] (event devices), you can game under macOS/QEMU or Windows/QEMU without any input lag. [1] https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-passthrough-notes https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-p... [2] https://passthroughpo.st/using-evdev-passthrough-seamless-vm-input/ https://passthroughpo.st/using-evdev-passthrough-seamless-vm...
- macinjosh 5y ago
  "you get 99% performance and 100% stability of a native Mac (not a single macOS/QEMU crash in years for me)" I am curious how this is so stable for you. Are you running this on Intel? Just last week I installed this on my AMD Linux workstation to test some stuff with Xcode and qemu would crash randomly while compiling LLVM/Clang.
  - gary17the 5y ago
    Yes, I run this on Intel i7, under Ubuntu 20.04, with QEMU 4.x, as "-machine q35".
- luzeal 5y ago
  By complicated, I mean that you have to modify your the default behavior of your host OS (which by default will grab any hardware) and pick a GPU that is supported by the guest OS. People with Nvidia GPUs cannot do that for macOS. Ideally, out-of-the-box, with a few clicks, most people including non-tech savy ones should be able to enjoy 3D acceleration in their VM, regardless of their host configuration. Besides, in the long term, Apple is likely to drop support for AMD or Intel GPU in their OS (but yes, they might also drop support for virtio devices). Yes, evdev is currently the best way to share your inputs devices to a VM, thank you for pointing that out (alas, it is only available in distributions with very recent virtualization-related packages). In my (perhaps narrow) view: virtualization should be about making you less reliant on the underlying hardware. I wish that GPU manufacturers would agree on a common standard to allow users to split their beefy GPU into smaller parts (Intel is apparently dropping support for vfio-mdev (Intel GVT-d), adopting SR/IOV instead for their latest offerings. But SR/IOV is only available on professional models for AMD and Nvidia. In summary, there won't be a standard any time soon, leaving virtio-gpu as the sole hardware-agnostic contender)
stuaxo 5y ago
Is there some info on virtio GPU for OSX development somewhere ? I knew virtio support was happening but hadn't seen any info on the GPU bit.
- AshamedCaptain 5y ago
  I'm quite sure virtio-gpu for OS X will _never_ happen unless Apple approves of it. 3D drivers are like the most closed things in OS X.
- luzeal 5y ago
  The port I had in mind is this one [1], and the use case is to make it possible to run 3D accelerated Linux guests on macOS hosts. I may have wrongly believed that it would be useful for macOS guests. Besides, it is correct that whatever happens on the driver side of things, Apple will have to approve it first (as the other reply pointed out) [1] https://mail.gnu.org/archive/html/qemu-devel/2021-02/msg04235.html https://mail.gnu.org/archive/html/qemu-devel/2021-02/msg0423...
  - my123 5y ago
    macOS guests use Apple’s own ParavirtualizedGraphics framework, which comes with none of the downsides of virtio-gpu. It pipes through serialised Metal at native performance.

by luzeal 5y ago

S5yDyAk3XoQH5 5y ago

Wow that's very surprising apple is trying to give better support for virtual environments instead of worse.. Do you know if they're allowing their iOS dev tools to run in there so you don't have to buy a mac anymore?

macinjosh 5y ago
I have been developing a toy iOS/macOS app running macOS with this. I am able to login with my dev program credentials and do everything I need. I haven't tried submitting anything to the store.
- mrkstu 5y ago
  So the virtualization hooks aren't just in MacOS? I could compile your app on my M1 iPad and run full MacOS virtually?
  - saagarjha 5y ago
    No, Apple doesn't expose virtualization on iPad.
dev_tty01 5y ago
Apple is adding better support for virtual environments running on the Mac. Not virtual macs running on other machines. That is all coming from the community.

gary17the 5y ago

> without having to care about trying to do complicated things ([...] pci-passthrough of a second GPU) Actually, GPU passthrough is quite simple: configure host Linux to assign a virtual driver to a secondary GPU on boot and configure QEMU to use that driver on guest boot[1]. If you buy a GPU that is natively supported by macOS (e.g., Sapphire Radeon RX 580 Pulse 4GB), you get 99% performance and 100% stability of a native Mac (not a single macOS/QEMU crash in years for me). Moreover, if you configure your QEMU mouse/keyboard to use evdev[2] (event devices), you can game under macOS/QEMU or Windows/QEMU without any input lag. [1] https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-passthrough-notes https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-p... [2] https://passthroughpo.st/using-evdev-passthrough-seamless-vm-input/ https://passthroughpo.st/using-evdev-passthrough-seamless-vm...

macinjosh 5y ago
"you get 99% performance and 100% stability of a native Mac (not a single macOS/QEMU crash in years for me)" I am curious how this is so stable for you. Are you running this on Intel? Just last week I installed this on my AMD Linux workstation to test some stuff with Xcode and qemu would crash randomly while compiling LLVM/Clang.
- gary17the 5y ago
  Yes, I run this on Intel i7, under Ubuntu 20.04, with QEMU 4.x, as "-machine q35".
luzeal 5y ago
By complicated, I mean that you have to modify your the default behavior of your host OS (which by default will grab any hardware) and pick a GPU that is supported by the guest OS. People with Nvidia GPUs cannot do that for macOS. Ideally, out-of-the-box, with a few clicks, most people including non-tech savy ones should be able to enjoy 3D acceleration in their VM, regardless of their host configuration. Besides, in the long term, Apple is likely to drop support for AMD or Intel GPU in their OS (but yes, they might also drop support for virtio devices). Yes, evdev is currently the best way to share your inputs devices to a VM, thank you for pointing that out (alas, it is only available in distributions with very recent virtualization-related packages). In my (perhaps narrow) view: virtualization should be about making you less reliant on the underlying hardware. I wish that GPU manufacturers would agree on a common standard to allow users to split their beefy GPU into smaller parts (Intel is apparently dropping support for vfio-mdev (Intel GVT-d), adopting SR/IOV instead for their latest offerings. But SR/IOV is only available on professional models for AMD and Nvidia. In summary, there won't be a standard any time soon, leaving virtio-gpu as the sole hardware-agnostic contender)

stuaxo 5y ago

Is there some info on virtio GPU for OSX development somewhere ? I knew virtio support was happening but hadn't seen any info on the GPU bit.

AshamedCaptain 5y ago
I'm quite sure virtio-gpu for OS X will _never_ happen unless Apple approves of it. 3D drivers are like the most closed things in OS X.
luzeal 5y ago
The port I had in mind is this one [1], and the use case is to make it possible to run 3D accelerated Linux guests on macOS hosts. I may have wrongly believed that it would be useful for macOS guests. Besides, it is correct that whatever happens on the driver side of things, Apple will have to approve it first (as the other reply pointed out) [1] https://mail.gnu.org/archive/html/qemu-devel/2021-02/msg04235.html https://mail.gnu.org/archive/html/qemu-devel/2021-02/msg0423...
- my123 5y ago
  macOS guests use Apple’s own ParavirtualizedGraphics framework, which comes with none of the downsides of virtio-gpu. It pipes through serialised Metal at native performance.