On 27.09.21 10:27, Stefan Hajnoczi wrote:
On Sun, Sep 26, 2021 at 10:16:14AM +0800, David Dai wrote:
Add a virtual pci to QEMU, the pci device is used to dynamically attach memory
to VM, so driver in guest can apply host memory in fly without virtualization
management software's help, such as libvirt/manager. The attached memory is
We do have virtio-mem to dynamically attach memory to a VM. It could be
extended by a mechanism for the VM to request more/less memory, that's
already a planned feature. But yeah, virito-mem memory is exposed as
ordinary system RAM, not only via a BAR to mostly be managed by user
space completely.
isolated from System RAM, it can be used in heterogeneous memory management for
virtualization. Multiple VMs dynamically share same computing device memory
without memory overcommit.
This sounds a lot like MemExpand/MemLego ... am I right that this is the
original design? I recall that VMs share a memory region and dynamically
agree upon which part of the memory region a VM uses. I further recall
that there were malloc() hooks that would dynamically allocate such
memory in user space from the shared memory region.
I can see some use cases for it, although the shared memory design isn't
what you typically want in most VM environments.
--
Thanks,
David / dhildenb
