crosvm/aarch64
David Dai e9426a6ace aarch64: devices: Add a virtual cpufreq device
Introduce support for a virtual CPU frequency device
to improve guest task placement behaviour along with performance
and power usage of workloads within VMs[1]. This device adds MMIO regions
that enables the guest to:

- Query for the frequency of the physical CPU that the current
vCPU is affined to.
- Send frequency requests that can be used as hint for the
host to schedule vCPU threads and choose physical CPU frequency.

Add a config option "--virt-cpufreq" that enables the virtual cpu device
and populates the frequencies of vCPUs through devicetree, which can
be used by a guest kernel cpufreq driver[2].

[1] https://lore.kernel.org/all/20230330224348.1006691-1-davidai@google.com/
[2] https://android-review.git.corp.google.com/c/kernel/common/+/2239182

Bug: None
Test: ./tools/presubmit
Change-Id: I03983c5e4a3fa288ca19504aa093ad1f7f9f7e51
Signed-off-by: David Dai <davidai@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4504738
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
2023-05-11 21:13:57 +00:00
..
src aarch64: devices: Add a virtual cpufreq device 2023-05-11 21:13:57 +00:00
.build_test_skip
Cargo.toml swap: expose Status interface to all variants 2023-05-04 12:30:09 +00:00