Commit graph

10 commits

Author SHA1 Message Date
Jorge E. Moreira
c8cff01c36 Specify prctl's policy only once per device
The libminijail version in AOSP complains when there are multiple entries for
the same system call, which was the case for virtio-fs's policy.

BUG=b/185811304

Change-Id: I389c07c86e7d79f16e4f47a893abad598033352a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2837307
Commit-Queue: Jorge Moreira Broche <jemoreira@google.com>
Tested-by: Jorge Moreira Broche <jemoreira@google.com>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2021-04-20 22:50:20 +00:00
Chirantan Ekbote
a00991cd84 Replace dup with fcntl(F_DUPFD_CLOEXEC)
Fds created via dup don't share file descriptor flags with the original
fd, which means that they don't have the FD_CLOEXEC flag set.  Use
fcntl(F_DUPFD_CLOEXEC) so that this flag gets set for the duplicated fds
as well.

BUG=none
TEST=unit tests

Change-Id: Ib471cf40acac1eacf72969ba45247f50b349ed58
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2809687
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
2021-04-15 10:34:04 +00:00
Dylan Reid
592f3275dd devices: Use async from balloon
The newly added async primitives allow for increasing the separation of
the various tasks performed by balloon. Breaking each task in to an
asynchronous function.

BUG=chromium:901139
TEST=Boot crosvm, run 'crosvm balloon' to set the balloon size, check
'vmstat' inside the VM to verify the free memory is affected by the
balloon growing and shrinking.
run crosvm balloon_stats command and ensure that stats are reported
correctly.

Change-Id: I0ae2be5eb8e4be65b2eb74de90888357af6ecfd4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1993163
Tested-by: Keiichi Watanabe <keiichiw@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Keiichi Watanabe <keiichiw@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2021-02-12 18:27:45 +00:00
Matt Delco
4389dab579 seccomp: remove redundant unconditional rules
Minijail's policy compiler complains when there's multiple
unconditional rules for a syscall.  In most cases the rules
are redundant to common_device.policy.  I don't know what
to do about the intentionally contradictory rules for open
and openat, other than to remove then from the common device
policy and add it to all the others.

BUG=None
TEST=Ran compile_seccomp_policy.py until it stopped
complaining.

Change-Id: I6813dd1e0b39e975415662bd7de74c25a1be9eb3
Signed-off-by: Matt Delco <delco@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1918607
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2020-01-22 17:36:36 +00:00
Zach Reizner
bae43dd4c9 seccomp: refactor policy into common_device.policy
CQ-DEPEND=CL:1449895
BUG=None
TEST=vmc start termina

Change-Id: Ia3edaafc1d2958bd40e6b1adc89dd5e29b679b06
Reviewed-on: https://chromium-review.googlesource.com/1448292
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
2019-02-07 03:02:12 -08:00
Chirantan Ekbote
448516e3f9 balloon: Implement device policy
Implement a policy for the balloon device so that it starts taking
memory away from the VM when the system is under low memory conditions.
There are a few pieces here:

* Change the madvise call in MemoryMapping::dont_need_range to use
  MADV_REMOVE instead of MADV_DONTNEED.  The latter does nothing when
  the memory mapping is shared across multiple processes while the
  former immediately gives the pages in the specified range back to the
  kernel.  Subsequent accesses to memory in that range returns zero
  pages.
* Change the protocol between the balloon device process and the main
  crosvm process.  Previously, the device process expected the main
  process to send it increments in the amount of memory consumed by the
  balloon device.  Now, it instead just expects the absolute value of
  the memory that should be consumed.  To properly implement the policy
  the main process needs to keep track of the total memory consumed by
  the balloon device so this makes it easier to handle all the policy in
  one place.
* Add a policy for dealing with low memory situations.  When the VM
  starts up, we determine the maximum amount of memory that the balloon
  device should consume:

    * If the VM has more than 1.5GB of memory, the balloon device max is
      the size of the VM memory minus 1GB.
    * Otherwise, if the VM has at least 500MB, the balloon device max is
      50% of the size of the VM memory.
    * Otherwise, the max is 0.

  The increment used to change the size of the balloon is defined as
  1/16 of the max memory that the balloon device will consume.  When the
  crosvm main process detects that the system is low on memory, it
  immediately increases the balloon size by the increment (unless it has
  already reached the max).  It then starts 2 timers: one to check for
  low memory conditions again in 1 seconds (+ jitter) and another to
  check if the system is no longer low on memory in 1 minute (+ jitter)
  with a subsequent interval of 30 seconds (+ jitter).

  Under persistent low memory conditions the balloon device will consume
  the maximum memory after 16 seconds.  Once there is enough available
  memory the balloon size will shrink back down to 0 after at most 9
  minutes.

BUG=chromium:866193
TEST=manual
Start 2 VMs and write out a large file (size > system RAM) in each.
Observe /sys/kernel/mm/chromeos-low_mem/available and see that the
available memory steadily decreases until it goes under the low memory
margin at which point the available memory bounces back up as crosvm
frees up pages.
CQ-DEPEND=CL:1152214

Change-Id: I2046729683aa081c9d7ed039d902ad11737c1d52
Signed-off-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1149155
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
2018-07-27 15:29:07 -07:00
Zach Reizner
fc62c45dab devices: use PollContext for all virtio deivces
BUG=chromium:816692
TEST=run any VM

Change-Id: I4219050fdb7947ca513f599f1ac57cde6052d397
Reviewed-on: https://chromium-review.googlesource.com/996917
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
2018-04-05 15:20:42 -07:00
Zach Reizner
5d586b73a4 sys_util: use MADV_DONTDUMP for new mmaps
The mmaps made through the sys_util API are usually for guest memory or
other large shared memory chunks that will pollute the file system with
huge dumps on crash. By using MADV_DONTDUMP, we save the file system
from storing these useless data segments when crosvm crashes.

TEST=./build_test
BUG=None

Change-Id: I2041523648cd7c150bbdbfceef589f42d3f9c2b9
Reviewed-on: https://chromium-review.googlesource.com/890279
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
2018-03-30 21:53:32 -07:00
Zach Reizner
fc44d8059b sys_util: add ppoll to seccomp policies
This really should have been added along with the poll timeout support,
which changed the syscalls used in every jailed device.

TEST=run crosvm with sandboxing enabled
BUG=None

Change-Id: I6129fa589640bb2b85fb4274775192bdd49db672
Reviewed-on: https://chromium-review.googlesource.com/890379
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
2018-01-27 01:36:52 -08:00
Dylan Reid
295ccac1f3 devices: Add balloon
The balloon device is used to take regions of unused memory from the
guest and allow other host processes to use that memory.

Change-Id: I06c821365a58672d605fc7555beaec599cae1b15
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/759306
Reviewed-by: Stephen Barber <smbarber@chromium.org>
2017-12-18 17:54:57 -08:00