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From:   Zhenzhong Duan <zhenzhong.duan@oracle.com>
To:     linux-kernel@vger.kernel.org
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        Zhenzhong Duan <zhenzhong.duan@oracle.com>,
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Subject: [PATCH v7 5/5] x86/hyperv: Mark "hv_nopvspin" parameter obsolete
Date:   Mon, 21 Oct 2019 17:11:16 +0800
Message-Id: <1571649076-2421-6-git-send-email-zhenzhong.duan@oracle.com>
In-Reply-To: <1571649076-2421-1-git-send-email-zhenzhong.duan@oracle.com>
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Map "hv_nopvspin" to "nopvspin".

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 6 +++++-
 arch/x86/hyperv/hv_spinlock.c                   | 4 ++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 85059dd..78648bb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1436,6 +1436,10 @@
 	hv_nopvspin	[X86,HYPER_V] Disables the paravirt spinlock optimizations
 				      which allow the hypervisor to 'idle' the
 				      guest on lock contention.
+				      This parameter is obsoleted by "nopvspin"
+				      parameter, which has equivalent effect for
+				      HYPER_V platform.
+
 
 	keep_bootcon	[KNL]
 			Do not unregister boot console at start. This is only
@@ -5335,7 +5339,7 @@
 			as generic guest with no PV drivers. Currently support
 			XEN HVM, KVM, HYPER_V and VMWARE guest.
 
-	nopvspin	[X86,XEN,KVM]
+	nopvspin	[X86,XEN,KVM,HYPER_V]
 			Disables the qspinlock slow path using PV optimizations
 			which allow the hypervisor to 'idle' the guest on lock
 			contention.
diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c
index 07f21a0..47c7d6c 100644
--- a/arch/x86/hyperv/hv_spinlock.c
+++ b/arch/x86/hyperv/hv_spinlock.c
@@ -64,6 +64,9 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
 
 void __init hv_init_spinlocks(void)
 {
+	if (nopvspin)
+		hv_pvspin = false;
+
 	if (!hv_pvspin || !apic ||
 	    !(ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) ||
 	    !(ms_hyperv.features & HV_X64_MSR_GUEST_IDLE_AVAILABLE)) {
@@ -82,6 +85,7 @@ void __init hv_init_spinlocks(void)
 
 static __init int hv_parse_nopvspin(char *arg)
 {
+	pr_notice("\"hv_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");
 	hv_pvspin = false;
 	return 0;
 }
-- 
1.8.3.1