Re: [PATCH v5 0/5] Add a unified parameter "nopvspin"

[Zhenzhong Duan <zhenzhong.duan@oracle.com>]

The last two patches are reviewed, will any KVM expert be willing to 
review the first three patches?

They are all KVM related changes. Thanks

Zhenzhong

On 2019/10/7 17:04, Zhenzhong Duan wrote:
> There are cases folks want to disable spinlock optimization for
> debug/test purpose. Xen and hyperv already have parameters "xen_nopvspin"
> and "hv_nopvspin" to support that, but kvm doesn't.
>
> The first patch adds that feature to KVM guest with "nopvspin".
>
> For compatibility reason original parameters "xen_nopvspin" and
> "hv_nopvspin" are retained and marked obsolete.
>
> v5:
> PATCH1: new patch to revert a currently unnecessory commit,
>          code is simpler a bit after that change.         [Boris Ostrovsky]
> PATCH3: fold 'if' statement,add comments on virt_spin_lock_key,
>          reorder with PATCH2 to better reflect dependency
> PATCH4: fold 'if' statement, add Reviewed-by             [Boris Ostrovsky]
> PATCH5: add Reviewed-by                                  [Michael Kelley]
>
> v4:
> PATCH1: use variable name nopvspin instead of pvspin and
>          defined it as __initdata, changed print message,
>          updated patch description                     [Sean Christopherson]
> PATCH2: remove Suggested-by, use "kvm-guest:" prefix  [Sean Christopherson]
> PATCH3: make variable nopvsin and xen_pvspin coexist
>          remove Reviewed-by due to code change         [Sean Christopherson]
> PATCH4: make variable nopvsin and hv_pvspin coexist   [Sean Christopherson]
>
> v3:
> PATCH2: Fix indentation
>
> v2:
> PATCH1: pick the print code change into separate PATCH2,
>          updated patch description             [Vitaly Kuznetsov]
> PATCH2: new patch with print code change      [Vitaly Kuznetsov]
> PATCH3: add Reviewed-by                       [Juergen Gross]
>
> Zhenzhong Duan (5):
>    Revert "KVM: X86: Fix setup the virt_spin_lock_key before static key
>      get initialized"
>    x86/kvm: Change print code to use pr_*() format
>    x86/kvm: Add "nopvspin" parameter to disable PV spinlocks
>    xen: Mark "xen_nopvspin" parameter obsolete
>    x86/hyperv: Mark "hv_nopvspin" parameter obsolete
>
>   Documentation/admin-guide/kernel-parameters.txt | 14 +++++-
>   arch/x86/hyperv/hv_spinlock.c                   |  4 ++
>   arch/x86/include/asm/qspinlock.h                |  1 +
>   arch/x86/kernel/kvm.c                           | 63 ++++++++++++++-----------
>   arch/x86/xen/spinlock.c                         |  4 +-
>   kernel/locking/qspinlock.c                      |  7 +++
>   6 files changed, 62 insertions(+), 31 deletions(-)
>