[RFC,0/9] Split kvm_update_cpuid_runtime()

Message

Robert Hoo July 31, 2020, 2:42 a.m. UTC

kvm_update_cpuid_runtime() is currently called by various functions for the
purpose of updating vCPU's cpuid entries, due to specific runtime changes, e.g.
CR4 bits changes, XCR0 bits changes, etc. Each of them actually just needs to
update 1 ~ 2 CPUID entries. But current kvm_update_cpuid_runtime() packages all.
Given finding a target CPUID entry need to go through all CPUID entries, calling
kvm_update_cpuid_runtime() is a waste for each cause.

This patch set splits kvm_update_cpuid_runtime() into pieces according to
different updating causes.
Then let various callers call their specific necessary kvm_xxx_update_cpuid().

This not only significantly saves each caller's time, but also eliminates
unnecessary couplings.

Robert Hoo (9):
  KVM:x86: Abstract sub functions from kvm_update_cpuid_runtime() and   
     kvm_vcpu_after_set_cpuid()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_apic_base_update_cpuid() in     kvm_lapic_set_base()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_xcr0_update_cpuid() in     __kvm_set_xcr()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_{osxsave,pke}_update_cpuid() in     kvm_set_cr4()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_mwait_update_cpuid() in     kvm_set_msr_common()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_{osxsave,pke}_update_cpuid() in     enter_smm()
  KVM:x86: Substitute kvm_update_cpuid_runtime() with
    kvm_{osxsave,pke}_update_cpuid() in     __set_sregs()
  KVM:x86: Substitute kvm_vcpu_after_set_cpuid() with abstracted
    functions
  KVM:x86: Remove kvm_update_cpuid_runtime()

 arch/x86/kvm/cpuid.c | 118 ++++++++++++++++++++++++++++++++++-----------------
 arch/x86/kvm/cpuid.h |   7 ++-
 arch/x86/kvm/lapic.c |   2 +-
 arch/x86/kvm/x86.c   |  29 ++++++++-----
 4 files changed, 103 insertions(+), 53 deletions(-)