The original Pit code encoded the start value of a timer into the
count_load_time field as a number of nanoseconds since the start of
the host's monotonic time value. Instead, we can use the PitCounter's
creation_time as the epoch. This makes the math look a bit more sensible
and removes the use of the non-portable clock_gettime() function.
Before
======
get_channel_state():
count_load_time = get_monotonic_time() - start.elapsed()
=== count_load_time = now() - (now() - start)
=== count_load_time = start
set_channel_state():
start = now() - (get_monotonic_time() - count_load_time)
=== start = now() - now() + count_load_time
=== start = count_load_time
After
=====
get_channel_state():
count_load_time = start - creation_time
set_channel_state():
start = creation_time + count_load_time
BUG=chromium:908689
BUG=b:213149155
TEST=cargo test -p devices pit
TEST=tools/run_tests --target=host --arch=win64
Change-Id: I5468d1d964a04b1ce96979ed583b729d139e1005
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3723804
Reviewed-by: Noah Gold <nkgold@google.com>
Reviewed-by: Vikram Auradkar <auradkar@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
crosvm is a virtual machine monitor (VMM) based on Linux’s KVM hypervisor, with a focus on
simplicity, security, and speed. crosvm is intended to run Linux guests, originally as a security
boundary for running native applications on the Chrome OS platform. Compared to QEMU, crosvm doesn’t
emulate architectures or real hardware, instead concentrating on paravirtualized devices, such as
the virtio standard.
crosvm is currently used to run Linux/Android guests on Chrome OS devices.
For contribution, see the contributor guide.
Mirror repository is available at GitHub for your
convenience, but we don't accept bug reports or pull requests there.
e5c6e65731
