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From:   Zhenzhong Duan <zhenzhong.duan@oracle.com>
To:     linux-kernel@vger.kernel.org
Cc:     vkuznets@redhat.com, linux-hyperv@vger.kernel.org,
        kvm@vger.kernel.org, kys@microsoft.com, haiyangz@microsoft.com,
        sthemmin@microsoft.com, sashal@kernel.org, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, pbonzini@redhat.com,
        rkrcmar@redhat.com, sean.j.christopherson@intel.com,
        wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org,
        boris.ostrovsky@oracle.com, jgross@suse.com,
        sstabellini@kernel.org, peterz@infradead.org,
        Zhenzhong Duan <zhenzhong.duan@oracle.com>
Subject: [PATCH v6 0/5] Add a unified parameter "nopvspin"
Date:   Tue, 15 Oct 2019 09:19:22 +0800
Message-Id: <1571102367-31595-1-git-send-email-zhenzhong.duan@oracle.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.

v6:
PATCH1: add Reviewed-by                                  [Vitaly Kuznetsov]
PATCH2: change 'pv' to 'PV', add Reviewed-by             [Vitaly Kuznetsov]
PATCH3: refactor 'if' branch in kvm_spinlock_init()      [Vitaly Kuznetsov]

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                           | 76 ++++++++++++++++---------
 arch/x86/xen/spinlock.c                         |  4 +-
 kernel/locking/qspinlock.c                      |  7 +++
 6 files changed, 75 insertions(+), 31 deletions(-)

-- 
1.8.3.1