Re: [ANNOUNCE] KVM Microconference at LPC 2024

[Gupta, Pankaj]

Hi Sean,

> We are planning on submitting a CFP to host a second annual KVM Microconference
> at Linux Plumbers Conference 2024 (https://lpc.events/event/18).  To help make
> our submission as strong as possible, please respond if you will likely attend,
> and/or have a potential topic that you would like to include in the proposal.
> The tentative submission is below.
>
> Note!  This is extremely time sensitive, as the deadline for submitting is
> April 4th (yeah, we completely missed the initial announcement).
>
> Sorry for the super short notice. :-(
>
> P.S. The Cc list is very ad hoc, please forward at will.
>
> ===================
> KVM Microconference
> ===================
>
> KVM (Kernel-based Virtual Machine) enables the use of hardware features to
> improve the efficiency, performance, and security of virtual machines (VMs)
> created and managed by userspace.  KVM was originally developed to accelerate
> VMs running a traditional kernel and operating system, in a world where the
> host kernel and userspace are part of the VM's trusted computing base (TCB).
>
> KVM has long since expanded to cover a wide (and growing) array of use cases,
> e.g. sandboxing untrusted workloads, deprivileging third party code, reducing
> the TCB of security sensitive workloads, etc.  The expectations placed on KVM
> have also matured accordingly, e.g. functionality that once was "good enough"
> no longer meets the needs and demands of KVM users.
>
> The KVM Microconference will focus on how to evolve KVM and adjacent subsystems
> in order to satisfy new and upcoming requirements.  Of particular interest is
> extending and enhancing guest_memfd, a guest-first memory API that was heavily
> discussed at the 2023 KVM Microconference, and merged in v6.8.
>
> Potential Topics:
>     - Removing guest memory from the host kernel's direct map[1]
>     - Mapping guest_memfd into host userspace[2]
>     - Hugepage support for guest_memfd[3]
>     - Eliminating "struct page" for guest_memfd
>     - Passthrough/mediated PMU virtualization[4]
>     - Pagetable-based Virtual Machine (PVM)[5]
>     - Optimizing/hardening KVM usage of GUP[6][7]
>     - Defining KVM requirements for hardware vendors
>     - Utilizing "fault" injection to increase test coverage of edge cases

Want to discuss the 'guest_memfd support for mirror VM'.

For SEV SNP live migration support, migration helper would run as a 
mirror VM. The mirror VM would use the existing KVM API's to copy the 
KVM context and populate the NPT page tables at page fault time. For 
designing the guest_memfd API's for mirror VM, want to consider the post 
copy use case as well so that the copying of paged-in memory in mirror 
VM would have a separate memory view.

Would like to attend and discuss with the community suggestions on the 
mirror VM with guestmem_fd implementation ideas to cater the use-cases.


Thanks,
Pankaj


> [1] https://lore.kernel.org/all/cc1bb8e9bc3e1ab637700a4d3defeec95b55060a.camel@xxxxxxxxxx
> [2] https://lore.kernel.org/all/20240222161047.402609-1-tabba@xxxxxxxxxx
> [3] https://lore.kernel.org/all/CABgObfa=DH7FySBviF63OS9sVog_wt-AqYgtUAGKqnY5Bizivw@xxxxxxxxxxxxxx
> [4] https://lore.kernel.org/all/20240126085444.324918-1-xiong.y.zhang@xxxxxxxxxxxxxxx
> [5] https://lore.kernel.org/all/20240226143630.33643-1-jiangshanlai@xxxxxxxxx
> [6] https://lore.kernel.org/all/CABgObfZCay5-zaZd9mCYGMeS106L055CxsdOWWvRTUk2TPYycg@xxxxxxxxxxxxxx
> [7] https://lore.kernel.org/all/20240320005024.3216282-1-seanjc@xxxxxxxxxx