general high-level discussion about spectrum
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From: Alyssa Ross <hi@alyssa.is>
To: Thomas Leonard <talex5@gmail.com>
Cc: Michael Raskin <7c6f434c@mail.ru>, discuss@spectrum-os.org
Subject: Qubes-lite With KVM and Wayland
Date: Tue, 9 Mar 2021 16:59:22 +0000	[thread overview]
Message-ID: <20210309165922.mg6hdqzzeurdmjsq@x220.qyliss.net> (raw)
In-Reply-To: <CAG4opy8BZn2pXDRBHOjcENFBHJON1LoG7A8GPdP0Wt_3KLaHyw@mail.gmail.com>

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On Sun, Mar 07, 2021 at 12:52:36PM +0000, Thomas Leonard wrote:
> On Wed, 27 Jan 2021 at 17:31, Thomas Leonard <talex5@gmail.com> wrote:
> [...]
> > If any of this sounds useful for spectrum let me know. I can try and
> > tidy it up; it's all a huge mess at the moment!
>
> I got a bit further (fixed my sommelier problems), but have run out of
> time for now :-(
>
> I've written up where I got to here:
>
> https://roscidus.com/blog/blog/2021/03/07/qubes-lite-with-kvm-and-wayland/

I saw this online the other day and started reading it without realising
it was you, and then I saw you were using Nix and thought "wow, that's
close to what I'm (not) doing", and then I saw the Spectrum section, and
then realised who the author was. :)

I'll quote a little from it and reply to bits:

> When I wanted a newer package (socat with vsock support, only just
> released) I just told Nix to install it from the latest Git checkout of
> nixpkgs.

I'm excited to learn that socat has vsock support now!  That's going to
be very useful.  I have a half-done patch somewhere that adds vsock
support to strace that I should finish up as well.

> True, my squashfs image is getting a bit big. Maybe I should instead
> make a minimal squashfs boot image, plus a shared directory of hard
> links to the required files. That would allow sharing the data with the
> host. I could also just share the whole /nix/store directory, if I
> wanted to make all host software available to guests.

I think the solution I will end up going with for this will be a custom
virtiofsd implementation that can implement some access controls.  The
even simpler solution would be to seperately expose every store path we
want to share as a virtio-fs device, but that's a lot of virtio devices!
(I vaguely remember the maximum might be as low as 16, too).

> I didn’t have time to write and debug C++ code for every missing
> Wayland protocol, so I took a short-cut: I wrote my own Wayland library,
> ocaml-wayland, and then used that to write my own version of sommelier.
> With that, adding support for copying text was fairly easy.

Well this is interesting!  I definitely want to learn more about this.

> * One problem with virtwl is that, while we can receive shared
>   memory FDs from the host, we can’t export guest  memory to the
>   host. This is unfortunate, because in Wayland the shared memory for
>   window contents is allocated by  the application from guest memory,
>   and the proxy therefore has to copy each frame. If the host
>   provided the  memory to the guest, this wouldn’t be needed. There
>   is a wl_drm protocol for allocating video memory, which might  help
>   here, but I don’t know how that works and, like many Wayland
>   specifications, it seems to be in the process of being replaced by
>   something else.

Yeah, this comes up on the virtio mailing list from time to time.  It's
a very difficult problem to solve, but there might be a solution some
day.  I think I've written about my own explorations in this area on
this list before.

> I’m not sure how guest-to-guest communication works with KVM.

It... doesn't really, at least not the way it does with Xen.
virtio-vhost-user[1] is promising, but very early stages.  I've talked
in quite a lot of detail about how that works on this list before as
well.  guest-to-guest communication was my main area of work for most of
the second half of last year (and what ended up causing me to burn out).

[1]: https://wiki.qemu.org/Features/VirtioVhostUser

> I hope the SpectrumOS project will resume at some point

Me too!  Maybe it's resuming right now!  (Although I'm not committing --
just because I'm feeling ready to get back into it today doesn't mean
that's going to be sustainable again yet.)

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  reply	other threads:[~2021-03-09 16:59 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-05 19:27 New user getting started questions Thomas Leonard
2021-01-05 20:09 ` Michael Raskin
2021-01-06  7:04   ` Alyssa's break Alyssa Ross
2021-01-06  9:11     ` Michał "rysiek" Woźniak
2021-01-06  7:00 ` New user getting started questions Alyssa Ross
2021-01-06 15:56   ` Thomas Leonard
2021-01-07 11:38     ` Thomas Leonard
2021-01-07 15:33     ` Thomas Leonard
2021-01-14 12:29     ` Alyssa Ross
2021-01-14 12:51       ` Alyssa Ross
2021-01-20 13:04         ` Thomas Leonard
2021-01-27 17:31           ` Thomas Leonard
2021-03-07 12:52             ` Thomas Leonard
2021-03-09 16:59               ` Alyssa Ross [this message]
2021-03-10 14:19                 ` Qubes-lite With KVM and Wayland Thomas Leonard
2021-03-10 22:34                   ` Alyssa Ross
2021-03-09 16:25             ` New user getting started questions Alyssa Ross
2021-03-13  7:21               ` Thomas Leonard
2021-03-13 13:52                 ` Alyssa Ross
2021-10-30 12:58                 ` Thomas Leonard
2021-11-03 11:36                   ` Alyssa Ross
2021-11-03 18:27                     ` Thomas Leonard
2021-11-10 12:58                       ` Alyssa Ross
2021-11-10 12:00                         ` Thomas Leonard
2021-11-11 11:09                           ` Alyssa Ross
2021-11-11 16:12                             ` Thomas Leonard
2021-11-12 10:47                               ` Alyssa Ross
2022-03-13 15:08                         ` Thomas Leonard
2022-03-15 14:06                           ` Alyssa Ross
2022-03-15 20:23                             ` Alyssa Ross
2022-03-16 16:18                               ` Using virtio-gpu instead of virtwl Thomas Leonard
2022-03-16 16:54                                 ` Alyssa Ross
2022-03-21 12:10                                 ` Thomas Leonard
2022-03-21 16:05                                   ` Alyssa Ross
2022-03-22 11:08                                     ` Thomas Leonard
2022-03-22 11:16                                       ` Alyssa Ross
2022-03-22 20:05                                         ` Thomas Leonard
2022-04-06 12:19                                           ` Thomas Leonard
2022-04-13 17:12                                             ` Thomas Leonard
2022-04-14 13:57                                               ` Alyssa Ross
2022-04-19 12:58                                                 ` Thomas Leonard
2022-04-19 12:01                                                   ` Alyssa Ross
2022-05-15 15:20                                                 ` Thomas Leonard
2022-05-16 11:55                                                   ` Alyssa Ross
2022-05-18  9:55                                                     ` Thomas Leonard
2022-06-05 16:29                                                       ` Thomas Leonard
2022-08-09 12:00                                     ` Alyssa Ross
2022-10-10 15:16                                       ` Thomas Leonard
2022-10-10 16:53                                         ` Alyssa Ross

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