This series add the ability to statistic the halt polling time when
VM execute HLT(arm is WFI).

v1:
https://listman.redhat.com/archives/libvir-list/2021-July/msg00029.html
v2:
https://listman.redhat.com/archives/libvir-list/2021-July/msg00339.html

changes from v1:
- Move virGetCgroupValueRaw to utils.c and rename it virGetValueRaw. So
  that we can call it to obtain halt polling time.
- Helper function virGetCpuHaltPollTime and virGetDebugFsKvmValue are
  added in a separate patch
- Use STRPREFIX to match the path prefix.
- Fix the logic that domstats will break when platform is non-linux,
  debugfs isn't mounted and so on.

change from v2:
- Drop patch 1, use virFileReadValueUllong() to get halt polling data.
- Delete unnecessary error report in logs.
- Remove the qemuDomainGetStatsCpuHaltPollTime function conditionally
  compiled on linux.
- Document the new parameters in src/libvirt-domain.c.

Yang Fei (2):
  util: Add virGetCpuHaltPollTime
  qemu: Introduce qemuDomainGetStatsCpuHaltPollTime

 src/libvirt-domain.c     |  7 +++++++
 src/libvirt_private.syms |  1 +
 src/qemu/qemu_driver.c   | 20 +++++++++++++++++++
 src/util/virutil.c       | 43 ++++++++++++++++++++++++++++++++++++++++
 src/util/virutil.h       |  4 ++++
 5 files changed, 75 insertions(+)

-- 
2.23.0