- Spectrum Development - spectrum-os.org

[PATCH crosvm] seccomp: allow getdents64 if getdents is allowed
by Alyssa Ross 05 Jun '20

05 Jun '20

This fixes a crash where crosvm would crash if run on x86_64 with --shared-dir when running ls in the shared directory. I suspect whether getdents or getdents64 is used depends on the host libc, so allow both of them. I suspect upstream's libc uses getdents, and that's why they haven't fixed the problem. --- This finally annoyed me enough that I decided to fix it. Michael, I think you'd also run into this issue. Want to test the fix? seccomp/x86_64/9p_device.policy | 1 + seccomp/x86_64/gpu_device.policy | 1 + seccomp/x86_64/xhci.policy | 1 + 3 files changed, 3 insertions(+) diff --git a/seccomp/x86_64/9p_device.policy b/seccomp/x86_64/9p_device.policy index 114ea11..271d244 100644 --- a/seccomp/x86_64/9p_device.policy +++ b/seccomp/x86_64/9p_device.policy @@ -18,6 +18,7 @@ unlink: 1 rename: 1 pread64: 1 getdents: 1 +getdents64: 1 mkdir: 1 rmdir: 1 fsync: 1 diff --git a/seccomp/x86_64/gpu_device.policy b/seccomp/x86_64/gpu_device.policy index 331fc49..99d2a8d 100644 --- a/seccomp/x86_64/gpu_device.policy +++ b/seccomp/x86_64/gpu_device.policy @@ -52,6 +52,7 @@ fstat: 1 # Used to set of size new memfd. ftruncate: 1 getdents: 1 +getdents64: 1 geteuid: 1 getrandom: 1 getuid: 1 diff --git a/seccomp/x86_64/xhci.policy b/seccomp/x86_64/xhci.policy index 4b4fc3d..3448ce2 100644 --- a/seccomp/x86_64/xhci.policy +++ b/seccomp/x86_64/xhci.policy @@ -38,4 +38,5 @@ ioctl: arg1 == 0xc0185500 || arg1 == 0x41045508 || arg1 == 0x8004550f || arg1 == fstat: 1 getrandom: 1 getdents: 1 +getdents64: 1 lseek: 1 -- 2.26.2

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[PATCH 1/2] chromiumOSPackages: improve update.py repo compat
by Alyssa Ross 02 Jun '20

02 Jun '20

These changes make chromiumOSPackages.updateScript better understand the Repo manifest format[1]. It now properly distinguishes between paths in the Chromium OS source tree and paths on the git servers, which are usually not the same. For example, chromiumos-overlay is located in the source tree at src/third_party/chromiumos-overlay, but on chromium.googlesource.com it's located at chromiumos/overlays/chromiumos-overlays. Components are now keyed by their location in the Chromium OS source tree (and packages have all been updated for this change.) Additionally, it now understands Repo remotes. This means that it is now possible to use a Chromium OS component like Minijail, which is hosted on android.googlesource.com rather than chromiumos.googlesource.com. This was not previously possible. [1]: https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md --- .../linux/chromium-os/common-mk/default.nix | 2 +- .../linux/chromium-os/crosvm/default.nix | 4 +- .../os-specific/linux/chromium-os/default.nix | 2 +- .../linux/chromium-os/libqmi/default.nix | 2 +- .../linux/chromium-os/minigbm/default.nix | 2 +- .../linux/chromium-os/modem-manager/next.nix | 2 +- .../linux/chromium-os/modp_b64/default.nix | 2 +- pkgs/os-specific/linux/chromium-os/update.py | 56 ++++++++++++------- .../linux/chromium-os/upstream-info.json | 40 ++++++------- pkgs/os-specific/linux/kernel/linux-cros.nix | 2 +- 10 files changed, 64 insertions(+), 50 deletions(-) diff --git a/pkgs/os-specific/linux/chromium-os/common-mk/default.nix b/pkgs/os-specific/linux/chromium-os/common-mk/default.nix index f07e418b56f..73862bcaa97 100644 --- a/pkgs/os-specific/linux/chromium-os/common-mk/default.nix +++ b/pkgs/os-specific/linux/chromium-os/common-mk/default.nix @@ -24,7 +24,7 @@ , ... } @ args: let - platform2 = fetchFromGitiles upstreamInfo.components."chromiumos/platform2"; + platform2 = fetchFromGitiles upstreamInfo.components."src/platform2"; attrsToGnList = lib.mapAttrsToList (name: value: "${name}=${toGn value}"); diff --git a/pkgs/os-specific/linux/chromium-os/crosvm/default.nix b/pkgs/os-specific/linux/chromium-os/crosvm/default.nix index 3813e3eb75a..8698ef67a83 100644 --- a/pkgs/os-specific/linux/chromium-os/crosvm/default.nix +++ b/pkgs/os-specific/linux/chromium-os/crosvm/default.nix @@ -9,10 +9,10 @@ let else throw "no seccomp policy files available for host platform"; crosvmSrc = fetchFromGitiles - upstreamInfo.components."chromiumos/platform/crosvm"; + upstreamInfo.components."src/platform/crosvm"; adhdSrc = fetchFromGitiles - upstreamInfo.components."chromiumos/third_party/adhd"; + upstreamInfo.components."src/third_party/adhd"; in rustPlatform.buildRustPackage rec { diff --git a/pkgs/os-specific/linux/chromium-os/default.nix b/pkgs/os-specific/linux/chromium-os/default.nix index f9c6c88d072..db719e8b0f1 100644 --- a/pkgs/os-specific/linux/chromium-os/default.nix +++ b/pkgs/os-specific/linux/chromium-os/default.nix @@ -9,7 +9,7 @@ let upstreamInfo = lib.importJSON ./upstream-info.json; chromiumos-overlay = (fetchFromGitiles - upstreamInfo.components."chromiumos/overlays/chromiumos-overlay") // { + upstreamInfo.components."src/third_party/chromiumos-overlay") // { passthru.updateScript = ./update.py; }; diff --git a/pkgs/os-specific/linux/chromium-os/libqmi/default.nix b/pkgs/os-specific/linux/chromium-os/libqmi/default.nix index ac444848b81..ec4f44c7047 100644 --- a/pkgs/os-specific/linux/chromium-os/libqmi/default.nix +++ b/pkgs/os-specific/linux/chromium-os/libqmi/default.nix @@ -8,7 +8,7 @@ libqmi.overrideAttrs ( pname = "libqmi-unstable"; version = "2019-12-16"; - src = fetchFromGitiles upstreamInfo.components."chromiumos/third_party/libqmi"; + src = fetchFromGitiles upstreamInfo.components."src/third_party/libqmi"; nativeBuildInputs = nativeBuildInputs ++ [ autoreconfHook autoconf-archive gtk-doc docbook-xsl-nons ]; diff --git a/pkgs/os-specific/linux/chromium-os/minigbm/default.nix b/pkgs/os-specific/linux/chromium-os/minigbm/default.nix index 0a3cbf15997..6c532a4deb2 100644 --- a/pkgs/os-specific/linux/chromium-os/minigbm/default.nix +++ b/pkgs/os-specific/linux/chromium-os/minigbm/default.nix @@ -4,7 +4,7 @@ stdenv.mkDerivation { name = "minigbm"; inherit (upstreamInfo) version; - src = fetchFromGitiles upstreamInfo.components."chromiumos/platform/minigbm"; + src = fetchFromGitiles upstreamInfo.components."src/platform/minigbm"; nativeBuildInputs = [ pkg-config ]; buildInputs = [ libdrm ]; diff --git a/pkgs/os-specific/linux/chromium-os/modem-manager/next.nix b/pkgs/os-specific/linux/chromium-os/modem-manager/next.nix index a074e82ff4b..91aa18b3846 100644 --- a/pkgs/os-specific/linux/chromium-os/modem-manager/next.nix +++ b/pkgs/os-specific/linux/chromium-os/modem-manager/next.nix @@ -9,7 +9,7 @@ modemmanager.overrideAttrs ( version = "2019-10-17"; src = fetchFromGitiles - upstreamInfo.components."chromiumos/third_party/modemmanager-next"; + upstreamInfo.components."src/third_party/modemmanager-next"; nativeBuildInputs = nativeBuildInputs ++ [ autoreconfHook libqmi libxslt ]; diff --git a/pkgs/os-specific/linux/chromium-os/modp_b64/default.nix b/pkgs/os-specific/linux/chromium-os/modp_b64/default.nix index 50d91479193..557769336ce 100644 --- a/pkgs/os-specific/linux/chromium-os/modp_b64/default.nix +++ b/pkgs/os-specific/linux/chromium-os/modp_b64/default.nix @@ -3,7 +3,7 @@ common-mk { platformSubdir = "modp_b64"; - src = fetchFromGitiles upstreamInfo.components."aosp/platform/external/modp_b64"; + src = fetchFromGitiles upstreamInfo.components."src/third_party/modp_b64"; installPhase = '' mkdir -p $out/lib diff --git a/pkgs/os-specific/linux/chromium-os/update.py b/pkgs/os-specific/linux/chromium-os/update.py index 1405c534d8b..58a15dbb8e8 100755 --- a/pkgs/os-specific/linux/chromium-os/update.py +++ b/pkgs/os-specific/linux/chromium-os/update.py @@ -13,16 +13,16 @@ from re import MULTILINE, fullmatch, match, search from urllib.request import urlopen # ChromiumOS components used in Nixpkgs -components = [ - 'aosp/platform/external/modp_b64', - 'chromiumos/overlays/chromiumos-overlay', - 'chromiumos/platform/crosvm', - 'chromiumos/platform/minigbm', - 'chromiumos/platform2', - 'chromiumos/third_party/adhd', - 'chromiumos/third_party/kernel', - 'chromiumos/third_party/libqmi', - 'chromiumos/third_party/modemmanager-next', +component_paths = [ + 'src/platform/crosvm', + 'src/platform/minigbm', + 'src/platform2', + 'src/third_party/adhd', + 'src/third_party/chromiumos-overlay', + 'src/third_party/kernel/v5.4', + 'src/third_party/libqmi', + 'src/third_party/modemmanager-next', + 'src/third_party/modp_b64', ] git_root = 'https://chromium.googlesource.com/' @@ -65,14 +65,28 @@ with urlopen(f'{buildspecs_url}{chrome_major_version}/?format=TEXT') as resp: buildspecs.sort(reverse=True) buildspec = splitext(buildspecs[0])[0] -revisions = {} +components = {} # Read the buildspec, and extract the git revisions for each component. with urlopen(f'{buildspecs_url}{chrome_major_version}/{buildspec}.xml?format=TEXT') as resp: xml = base64.decodebytes(resp.read()) root = etree.fromstring(xml) + + default_remote = root.find('default').get('remote') + remotes = {} + for remote in root.findall('remote'): + remotes[remote.get('name')] = remote.get('fetch') + for project in root.findall('project'): - revisions[project.get('name')] = project.get('revision') + name = project.get('name') + path = project.get('path') + remote_name = project.get('remote') or default_remote + remote = remotes[remote_name] + + components[path] = { + 'revision': project.get('revision'), + 'url': f'{remote}/{name}', + } # Initialize the data that will be output from this script. Leave the # rc number in buildspec so nobody else is subject to the same level @@ -84,15 +98,15 @@ paths = {} # Fill in the 'components' dictionary with the output from # nix-prefetch-git, which can be passed straight to fetchGit when # imported by Nix. -for component in components: - name = component.split('/')[-1] - url = f'{git_root}{component}' - rev = revisions[component] +for path in component_paths: + name = path.split('/')[-1] + url = components[path]['url'] + rev = components[path]['revision'] tarball = f'{url}/+archive/{rev}.tar.gz' output = subprocess.check_output(['nix-prefetch-url', '--print-path', '--unpack', '--name', name, tarball]) - (sha256, path) = output.decode('utf-8').splitlines() - paths[component] = path - data['components'][component] = { + (sha256, store_path) = output.decode('utf-8').splitlines() + paths[path] = store_path + data['components'][path] = { 'name': name, 'url': url, 'rev': rev, @@ -100,14 +114,14 @@ for component in components: } # Get the version number of the kernel. -kernel = paths['chromiumos/third_party/kernel'] +kernel = paths['src/third_party/kernel/v5.4'] makefile = open(f'{kernel}/Makefile').read() version = search(r'^VERSION = (.+)$', makefile, MULTILINE)[1] patchlevel = search(r'^PATCHLEVEL = (.*?)$', makefile, MULTILINE)[1] sublevel = search(r'^SUBLEVEL = (.*?)$', makefile, MULTILINE)[1] extra = search(r'^EXTRAVERSION =[ \t]*(.*?)$', makefile, MULTILINE)[1] full_ver = '.'.join(filter(None, [version, patchlevel, sublevel])) + extra -data['components']['chromiumos/third_party/kernel']['version'] = full_ver +data['components']['src/third_party/kernel/v5.4']['version'] = full_ver # Finally, write the output. with open(dirname(__file__) + '/upstream-info.json', 'w') as out: diff --git a/pkgs/os-specific/linux/chromium-os/upstream-info.json b/pkgs/os-specific/linux/chromium-os/upstream-info.json index 5264a72a6c9..842912800bc 100644 --- a/pkgs/os-specific/linux/chromium-os/upstream-info.json +++ b/pkgs/os-specific/linux/chromium-os/upstream-info.json @@ -1,60 +1,60 @@ { "version": "81.12871.0.0-rc1", "components": { - "aosp/platform/external/modp_b64": { - "name": "modp_b64", - "url": "https://chromium.googlesource.com/aosp/platform/external/modp_b64", - "rev": "ae26ad8516036774fd3b6e84a98a89955dcf5f61", - "sha256": "03ja5fkq3wk0qcnfnqcj09lciky6n6zdj544xs1jfssjhz9yj8hi" - }, - "chromiumos/overlays/chromiumos-overlay": { - "name": "chromiumos-overlay", - "url": "https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay", - "rev": "be285b729ef2af700cc248f741af20c387b5a1bc", - "sha256": "18y2icdb3hxqxxaaz8sylw21q2qwcpjyns75ig7ahc4vc1k5hg7s" - }, - "chromiumos/platform/crosvm": { + "src/platform/crosvm": { "name": "crosvm", "url": "https://chromium.googlesource.com/chromiumos/platform/crosvm", "rev": "8b8c01e1ad31718932491e4aee63f56109a138e2", "sha256": "1qmf1k06pwynh15c3nr9m6v90z2pkk930xniwvlvbvnazrk4rllg" }, - "chromiumos/platform/minigbm": { + "src/platform/minigbm": { "name": "minigbm", "url": "https://chromium.googlesource.com/chromiumos/platform/minigbm", "rev": "fbfb338e7db246f05ae68da97141fbd49481584b", "sha256": "11p6v4nmqivyqyc8lmypbwqv9q819lhx6v3igfsv3455mmq02kcb" }, - "chromiumos/platform2": { + "src/platform2": { "name": "platform2", "url": "https://chromium.googlesource.com/chromiumos/platform2", "rev": "6e0d88d0bea8e7cb28a310298cc8c77ed742f60a", "sha256": "13vrbnl3ck8cxiyifc58cs9i0yby92vp5si27ihrx33v6bdlir4s" }, - "chromiumos/third_party/adhd": { + "src/third_party/adhd": { "name": "adhd", "url": "https://chromium.googlesource.com/chromiumos/third_party/adhd", "rev": "f361d5b02623274723bff251dafa1e2a2887b013", "sha256": "1p8iwjwgmcgmzri03ik2jaid8l0ch0bzn6z9z64dix1hlrvrlliw" }, - "chromiumos/third_party/kernel": { - "name": "kernel", + "src/third_party/chromiumos-overlay": { + "name": "chromiumos-overlay", + "url": "https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay", + "rev": "be285b729ef2af700cc248f741af20c387b5a1bc", + "sha256": "18y2icdb3hxqxxaaz8sylw21q2qwcpjyns75ig7ahc4vc1k5hg7s" + }, + "src/third_party/kernel/v5.4": { + "name": "v5.4", "url": "https://chromium.googlesource.com/chromiumos/third_party/kernel", "rev": "17611b6e636c8ccae25e873e659d69c20b215815", "sha256": "0an8w3660v2zf2crb68ambg7vzw2rajpjmcby1am08qy37lqsfkd", "version": "5.4.16" }, - "chromiumos/third_party/libqmi": { + "src/third_party/libqmi": { "name": "libqmi", "url": "https://chromium.googlesource.com/chromiumos/third_party/libqmi", "rev": "6267c12fef0be9a95d687bf4b476593eeffbaaf1", "sha256": "00yjjcngjkbgxmmf79ciddk9yq393a94230ahq8vszyfygzhs3rz" }, - "chromiumos/third_party/modemmanager-next": { + "src/third_party/modemmanager-next": { "name": "modemmanager-next", "url": "https://chromium.googlesource.com/chromiumos/third_party/modemmanager-next", "rev": "a4d3a4de1fdab7c282f1a188d2d3d0aaa24f0698", "sha256": "1b1l1jfiyl7fnm29pp9npi0gdlqcw1jmmbigf0qlndqdh0ly2izg" + }, + "src/third_party/modp_b64": { + "name": "modp_b64", + "url": "https://chromium.googlesource.com/aosp/platform/external/modp_b64", + "rev": "ae26ad8516036774fd3b6e84a98a89955dcf5f61", + "sha256": "03ja5fkq3wk0qcnfnqcj09lciky6n6zdj544xs1jfssjhz9yj8hi" } } } diff --git a/pkgs/os-specific/linux/kernel/linux-cros.nix b/pkgs/os-specific/linux/kernel/linux-cros.nix index 6a4a5771b38..789a9fb6fd2 100644 --- a/pkgs/os-specific/linux/kernel/linux-cros.nix +++ b/pkgs/os-specific/linux/kernel/linux-cros.nix @@ -3,7 +3,7 @@ , ... } @ args: let - versionData = upstreamInfo.components."chromiumos/third_party/kernel"; + versionData = upstreamInfo.components."src/third_party/kernel/v5.4"; in with lib; -- 2.26.2

3 15

This Week in Spectrum, 2020-W22
by Alyssa Ross 30 May '20

30 May '20

I began this week feeling very burnt out from some Nix stuff. Later in the week, I got sick as well (thankfully not with any COVID-19 symptoms) and ended up spending several days not being able to do much beyond sleep. So, not a lot from me to report this week I'm afraid. This'll be a short one. Documentation ------------- I documented the memfd server I recently added to crosvm[1]. I sent the documentation patch to the list, and was very pleased to receive reviews[2] from impaqt and Cole Helbling. This is really the first time a patch from me has gone through an actual review cycle with other people involved, so that's very exciting. Here's to more of that! :) With that documentation, I was then able to add a memfd server quota to the Contribution Ideas page[3]. This is an important feature, so if nobody is interested in working on it I'll do it myself, but it's also a nice opportunity to do a pretty self-contained bit of work on crosvm, so I'm going to leave it up for a bit in case somebody else wants to try it. [1]: https://spectrum-os.org/doc/developer-manual.html#_the_memfd_server [2]: https://spectrum-os.org/lists/archives/spectrum-devel/C312TALEYVQS.RICE3VLE… [3]: https://spectrum-os.org/todo.html Infrastructure -------------- Increased the maximum message size on devel@ to 80K from 40K, because a patch I sent was too big and got held for moderation. Nixpkgs ------- The expected Chromium OS update was released this week (instead of last as I'd expected). crosvm now wants the minijail source code, which isn't hosted on chromium.googlesource.com. This required making the update script a bit smarter. I posted the patch series improving the update script and then updating chromiumOSPackages to the list[1]. More details there. Another shout out to Cole for having a go at doing this update, even if he didn't get all the way because he needed the cores on his computer for other things. Thanks Cole! [1]: https://spectrum-os.org/lists/archives/spectrum-devel/20200530190028.6388-1… I'm mostly feeling better now (although still getting tired very easily), so hopefully things will go faster again next week. Too early to be certain, though. I'm happy to have at least got the chromiumOSPackages update out the way, and delighted to have received the reviews on the documentation patch.

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[PATCH www] todo.html: add request for memfd server ceiling
by Alyssa Ross 29 May '20

29 May '20

--- I pushed this already, but I'm posting it here in case anybody is interested in doing it. ;) todo.html | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/todo.html b/todo.html index abb9c11..417b3c3 100644 --- a/todo.html +++ b/todo.html @@ -48,6 +48,11 @@ might be able to help out. <a href="https://spectrum-os.org/git/nixpkgs/tree/pkgs/development/libraries/wlroots…">patch</a> wlroots to downgrade it to an older protocol. + <li> + Implement a ceiling for host memory allocated by the + crosvm <a href="https://spectrum-os.org/doc/developer-manual.html#_the_memfd_server">memfd + server</a>. + <li> Create a minimal VM kernel configuration. This will make it much easier to iterate on the VM kernel, by substantially reducing clean -- 2.26.2

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[PATCH doc] Document crosvm memfd server
by Alyssa Ross 29 May '20

29 May '20

--- Looking for another set of eyes on this to check it makes sense to people who haven't dedicated several weeks of their life to thinking about it. ;) developer-manual.adoc | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/developer-manual.adoc b/developer-manual.adoc index a538437..5a5f80d 100644 --- a/developer-manual.adoc +++ b/developer-manual.adoc @@ -194,6 +194,31 @@ compile the policy files into the crosvm binary so paths don't have to be hardcoded. +==== The memfd server + +Spectrum's crosvm has been augmented with a feature called the +"`memfd server`", (currently only on the +https://spectrum-os.org/git/crosvm/log/?h=interguest[interguest] +branch). This is a small server that listens on a Unix stream socket. +It receives a request consisting of a name and a size, uses those to +allocate a receives requests for a +https://man7.org/linux/man-pages/man2/memfd_create.2.html[memfd], and +then sends the resulting memfd file descriptor back over the socket in +response, along with a single byte status code. + +The purpose of this is that it can be exposed to the guest over +virtio_wl. This means that the guest can request and receive +allocations of host memory. This is important, because virtio_wl only +allows file descriptors pointing to host memory to be sent over +virtio_wl -- a memfd allocated in a guest cannot be sent over virtio_wl. +It is rare that a guest needs to be able to allocate and send shared +memory in this way, but it is important for a Wayland compositor +running in a guest to be able to do this. + +The memfd server is disabled by default, but is enabled at startup +time with the `--wl-memfd` flag. + + === Sommelier https://chromium.googlesource.com/chromiumos/platform2/+/master/vm_tools/so… -- 2.26.2

3 6

This Week in Spectrum, 2020-W21
by Alyssa Ross 24 May '20

24 May '20

A week of results! Infrastructure -------------- Fixed a misconfigured spam filter that allowed an obvious spam message through to devel@. Oops. crosvm ------ Integrated the memfd server[1] on the interguest branch. It's now all sandboxed, and optionally enabled with a command line argument to crosvm run. Not all that much to say here, but it's what took me most of the week! Getting the sandbox working was a bit weird. When I tried to get it to log seccomp failures, it seemed to just disable the sandbox. I had to track them down with strace instead. Annoying. But the sandbox does work in normal operation. I still haven't limited how much memory can be requested this way. I think implementing that would be relatively straightforward for another contributor, so I think I'll add it to the ideas list[2] and see if a patch is forthcoming. Otherwise I'll do it myself. [1]: https://spectrum-os.org/git/crosvm/commit/?h=interguest [2]: https://spectrum-os.org/todo.html wlroots ------- I took my standalone virtio_wl test program, and integrated it into wlroots' allocate_shm_file function. This has the result that, when running under Sommelier, this patched wlroots will request shared memory from the host, rather than allocating it itself. Porting from the standalone test program was nice, because it meant that this all just worked, first try! (Once I got it to compile under Nixpkgs' or wlroots' strict compiler errors, at least.) This will allow that memory to be sent between VMs! I haven't pushed the patch yet because I haven't integrated it into Spectrum's Nixpkgs yet. I plan to do that next week. I'm starting to think about moving the stuff specific to Spectrum VMs into an overlay, but I need to think a bit about how to structure that. Nixpkgs ------- There's no sign of the expected Chromium OS release so far, so I backported[3] support for multiple virtio_wl sockets from a more recent Chromium OS kernel to the one in Spectrum's Nixpkgs. We need this to be able to dedicate a named socket to the memfd server. [3]: https://spectrum-os.org/git/nixpkgs/commit/?id=f24d310275909265de32cbc831d5… It's been another week where I've been very focused on one task. I'm quite excited about the direction this is all going. It's looking like we'll be able to do almost everything inside VMs, which means it might be possible to have a host kernel that does almost nothing apart from KVM and PCI passthrough?? This would mean we'd end up with a tiny Linux a little bit (but not all that much) like a microkernel, with most hardware interaction and all user programs running in VMs. Cool stuff! It's not clear to me yet the exact extent to which this is achievable, but it's a nice vision to keep in mind. It might also make it easier for us to transition to a true microkernel at some point in the future. I'm hoping that I'll hit an NLnet milestone related to this stuff fairly soon. Until I do, I'm now living on the money I've received in the past six months through GitHub Sponsors. Thank you so much to everyone who is helping to make it possible for me to spend this time on the fundamentals so we have a good foundation to build Spectrum on. <3

1 0

Spam on this list
by Alyssa Ross 18 May '20

18 May '20

Hi, Apologies for the recent spam message on the list. It got through due to a misconfigured spam filter. Should be fixed now. Let me know if you see anything else unusual. :)

1 0

This Week in Spectrum, 2020-W20
by Alyssa Ross 17 May '20

17 May '20

It feels like things are finally starting to come together. Infrastructure -------------- Server memory upgraded. We should now be able to handle more than one person cloning Spectrum's nixpkgs repo at once! Documentation ------------- I added a much requested page[1] to the website with a few tasks a potential contributor might want to look into. More to come here, too! [1]: https://spectrum-os.org/todo.html virtio_wl --------- I wrote a simple guest C program that connected to a host socket over virtio_wl, and sent some messages back and forth. In doing this, I've ended up with a nice set of generic functions for interacting with virtio_wl -- virtio_wl_connect(), virtio_wl_send(), etc. This is nice, because it allows me to treat virtio_wl inside a guest much like a regular socket (albeit one that can only be interacted with using a custom set of functions). Otherwise, I'd have to do ioctl operations every time (which seems to be what the various virtio_wl-using Chromium OS components do). Having a simple test program (rather than integrating directly into wlroots) gives me a more simple environment with which to test the other end of this connection. crosvm ------ I implemented a little Rust server that listens on a Unix stream socket. When it receives a message (consisting of an identifier {for debug purposes} and a size), it will allocate a memfd of the requested size, and then send that back to the socket, along with a status byte indicating success or failure. I then integrated this program into crosvm, so it is started as part of the VM initialization, and exposed over virtio_wl as an additional socket. Integrating this into crosvm required some careful thought, because there's no precedent in crosvm for a virtio_wl server of this sort. It has almost nothing with the existing concept in crosvm of a "device", which is something that communicates with a guest kernel driver over PCI. So Spectrum's crosvm now has the concept of "servers". I can see us wanting to provide other VM services over virtio_wl in the future. It allows us to exchange various resources between host and guest (or between guests) without having to write a kernel driver specific to each task. This all now works well enough that my program inside the VM can request a chunk of memory, and receive back something that looks a bit like a memfd, that can then be sent back to the host over a virtio_wl socket. It was great to see this working the first time! One thing crosvm devices do that I would also like to apply to this type of server is sandboxing. The sandboxing mechanism used in crosvm is pretty generic (it's really just a thin wrapper around Minijail[2]), so it should be straightforward to reuse. I just have to understand a bit better how to use it. The other crosvm change I still need to make is to put this functionality behind a command line flag. Most VMs should not be able to give themselves extra memory this way -- really only the Wayland compositor should be using it. I should also impose some upper bound on how much memory is allowed to be allocated this way. Such a limit will probably get harder to add (from a testing point of view) the longer I wait. [2]: https://lwn.net/Articles/700557/ So, at lot of very focused progress this week. From here I plan to finish up the crosvm stuff, and then integrate this protocol into wlroots. Then, not too long from now, we'll finally be able to move the Wayland compositor into its own VM, separate from applications. Exciting! There will also probably be a Chromium OS release next week, which will require some updates in Spectrum. If all goes well, I won't actually be the one doing that this time. ;)

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[PATCH www] todo.html: fix 'appears' -> 'appeals'
by Vincent Ambo 15 May '20

15 May '20

Hello world o/ --- todo.html | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/todo.html b/todo.html index fd8bc04..b8c091a 100644 --- a/todo.html +++ b/todo.html @@ -26,7 +26,7 @@ system available to experiment with yet. <p> Here are some ideas for contributions, roughly ordered by priority. -If working on any of these appears to you, even if you don't +If working on any of these appeals to you, even if you don't understand all the parts involved, we'd be happy to provide mentorship and support. Just reach out on <a href="participating.html#irc">IRC</a> or email -- 2.26.2.761.g0e0b3e54be-goog

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oops
by impaqt 13 May '20

13 May '20

sorry, this isn't devel-subscribe...

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