This patchset adds a pmu=[on/off] option to enable/disable vPMU support
for guest VM. There are several reasons to justify this option. First,
vPMU can be problematic for cross-migration between different SoC as perf
counters are architecture-dependent. It is more flexible to have an option
to turn it on/off. Secondly this option matches the "pmu" option as
supported in libvirt. To make sure backward compatible, a PMU-related
property is added to mach-virt machine types.
The following are testing results with this patchset:
CONFIG (qemu-system-aarch64) vPMU WARNING
-M virt-2.8/virt,accel=kvm -cpu host YES NO
-M virt-2.8/virt,accel=kvm -cpu host,pmu=off NO NO
-M virt-2.8/virt,accel=kvm -cpu host,pmu=on YES NO
-M virt-2.7,accel=kvm -cpu host YES NO
-M virt-2.7,accel=kvm -cpu host,pmu=off NO NO
-M virt-2.7,accel=kvm -cpu host,pmu=on YES NO
-M virt-2.6,accel=kvm -cpu host NO NO
-M virt-2.6,accel=kvm -cpu host,pmu=off NO NO
-M virt-2.6,accel=kvm -cpu host,pmu=on NO NO
-M virt-2.8/virt,accel=tcg -cpu cortex-a57 NO NO
-M virt-2.8/virt,accel=tcg -cpu cortex-a57,pmu=off NO NO
-M virt-2.8/virt,accel=tcg -cpu cortex-a57,pmu=on NO NO
-M virt-2.7,accel=tcg -cpu cortex-a57 NO NO
-M virt-2.7,accel=tcg -cpu cortex-a57,pmu=off NO NO
-M virt-2.7,accel=tcg -cpu cortex-a57,pmu=on NO NO
-M virt-2.6,accel=tcg -cpu cortex-a57 NO NO
-M virt-2.6,accel=tcg -cpu cortex-a57,pmu=off NO NO
-M virt-2.6,accel=tcg -cpu cortex-a57,pmu=on NO NO
-M virt-2.8/virt,accel=tcg -cpu cortex-a15 NO NO
-M virt-2.8/virt,accel=tcg -cpu cortex-a15,pmu=off NO "No PMU property"
-M virt-2.8/virt,accel=tcg -cpu cortex-a15,pmu=on NO "No PMU property"
-M virt-2.7,accel=tcg -cpu cortex-a15 NO NO
-M virt-2.7,accel=tcg -cpu cortex-a15,pmu=off NO "No PMU property"
-M virt-2.7,accel=tcg -cpu cortex-a15,pmu=on NO "No PMU property"
-M virt-2.6,accel=tcg -cpu cortex-a15 NO NO
-M virt-2.6,accel=tcg -cpu cortex-a15,pmu=off NO "No PMU property"
-M virt-2.6,accel=tcg -cpu cortex-a15,pmu=on NO "No PMU property"
* "No PMU property" msg
can't apply global cortex-a15-arm-cpu.pmu=off: Property '.pmu' not found
V7->V8:
* add back the "pmu" property for TCG mode
V6->V7:
* change has_pmu variable type from OnOffAuto to Boolean
* only add "pmu" property to CPU under kvm mode, default ON
* set no_pmu=true for machvirt-2.6
V5->V6:
* adapt patches for new machine type 2.8
V4->V5:
* remove comment change for has_pmu
* remove warning msg when pmu_default_on=TRUE && has_pmu=AUTO && tcg=TRUE
V3->V4:
* change has_pmu from Boolean to OnOffAuto to handle different cases
* "pmu" property is re-defined as DEFINE_PROP_ON_OFF_AUTO
V2->V3:
* revise patch 1 commit msg and if-else statement (Drew)
* move property field into VirtMachineClass (Drew)
V1->V2:
* keep the original field name as "has_pmu"
* add a warning message when PMU is turned on without KVM
* use the feature bit to check PMU availability, instead of using has_pmu
* add PMU compat support to mach-virt machine type
RFC->V1:
* set default pmu=off
* change struct ARMCPU field name "has_pmu" ==> "has_host_pmu"
* like el3, add a new feature ARM_FEATURE_HOST_PMU
* "pmu" property becomes CPU dependent. Only cortex-a53/cortex-a57/host
running on kvm supports this option.
Thanks,
-Wei
Wei Huang (2):
arm: Add an option to turn on/off vPMU support
arm: virt: add PMU property to mach-virt machine type
hw/arm/virt-acpi-build.c | 2 +-
hw/arm/virt.c | 9 ++++++++-
target-arm/cpu.c | 15 +++++++++++++++
target-arm/cpu.h | 1 +
target-arm/cpu64.c | 2 ++
target-arm/kvm64.c | 17 ++++++++++++++---
6 files changed, 41 insertions(+), 5 deletions(-)
--
1.8.3.1
