Re: [PATCH v3 0/4] misc: vmw_zerocopy: VMware zero-copy buffer sharing driver

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Sep 14, 2026 at 01:22:05PM -0700, Rishi Chhibber wrote:
> Summary of changes:
> - 1/4 reserves a VMCI datagram resource id for the hypervisor-side
>   zero-copy service
> - 2/4 adds the vmw_zerocopy driver: /dev/vmw_zc, a single ioctl, page
>   pinning and the VMCI datagram transport
> - 3/4 documents the userspace interface
> - 4/4 adds a kselftest covering the ioctl input-validation paths
> 
> This series adds a misc character device, /dev/vmw_zc, that lets guest
> userspace hand a buffer to a VMware hypervisor-side peer without copying
> it. The driver pins the user pages, collects their guest physical frame
> numbers and sends that list over a VMCI datagram; the hypervisor then
> reads the buffer directly out of guest memory. An optional metadata
> buffer is pinned writable so the peer can return a result through the
> same mechanism.

You are going to need to get the -mm maintainers/developers to sign off
on this thing before I can accept it due to your "fun" use of memory
buffers in here.

thanks,

greg k-h