Re: [LSF/MM/BPF TOPIC] Virtual Machine Memory Passthrough

[Pasha Tatashin <pasha.tatashin@soleen.com>]

On Mon, Feb 20, 2023 at 11:38 PM Zhu Yanjun <zyjzyj2000@gmail.com> wrote:
>
> On Tue, Feb 21, 2023 at 12:32 AM Pasha Tatashin
> <pasha.tatashin@soleen.com> wrote:
> >
> > Hello,
> >
> > As a part of an ongoing work of replacing some containerized work load
> > with virtual machines within Google, I have worked on making the
> > memory translations faster.
> >
> > I would like to propose the following topic for this year's LSF/MM/BPF:
> >
> > Discuss  a set of techniques that can improve the guest performance,
> > memory footprint overhead, observability, and manageability of virtual
> > machines by hypervirtualizing the guest memory to the extreme. The end
> > goal is to allow very lightweight virtual machines to be closer in
> > performance to the containers.
> >
> > The following items are going to be discussed in this topic:
> > - Reducing the cost of SLAT page table translations.
>
> Intel's implementation of SLAT, known as Extended Page Table (EPT),
> was introduced in the Nehalem microarchitecture found in certain Core
> i7, Core i5, and Core i3 processors.
> ARM's virtualization extensions support SLAT, known as Stage-2
> page-tables provided by a Stage-2 MMU. The guest uses the Stage-1 MMU.
> Support was added as optional in the ARMv7ve architecture and is also
> supported in the ARMv8 (32-bit and 64-bit) architectures.
> I am interested in this. Hope we have a better solution to reduce the
> cost of SLAT.

Hi Zhu,

Please take a look at my previous reply to Gavin Shan where I clarify
the SLAT performance improvements.

Thanks,
Pasha

>
> > - Reducing the memory footprint overhead.
> > - Reducing the memory management overhead.
> > - Increasing the observability of guest memory.
> >