Re: [PATCH v3 4/4] x86/hyperv: Mark "hv_nopvspin" parameter obsolete and map it to "nopvspin"

From: Zhenzhong Duan <zhenzhong.duan@oracle.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-kernel@vger.kernel.org, vkuznets@redhat.com,
	linux-hyperv@vger.kernel.org, kvm@vger.kernel.org,
	Jonathan Corbet <corbet@lwn.net>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Sasha Levin <sashal@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v3 4/4] x86/hyperv: Mark "hv_nopvspin" parameter obsolete and map it to "nopvspin"
Date: Thu, 3 Oct 2019 19:22:17 +0800	[thread overview]
Message-ID: <f52083d6-9964-c995-1acf-a11ed1dbf935@oracle.com> (raw)
In-Reply-To: <20191002171952.GE9615@linux.intel.com>

On 2019/10/3 1:19, Sean Christopherson wrote:
> On Mon, Sep 30, 2019 at 08:44:39PM +0800, Zhenzhong Duan wrote:
>> Includes asm/hypervisor.h in order to reference x86_hyper_type.
>>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.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>
>> ---
...snip
>> @@ -64,7 +63,7 @@ __visible bool hv_vcpu_is_preempted(int vcpu)
>>   
>>   void __init hv_init_spinlocks(void)
>>   {
>> -	if (!hv_pvspin || !apic ||
>> +	if (!pvspin || !apic ||
>>   	    !(ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) ||
>>   	    !(ms_hyperv.features & HV_X64_MSR_GUEST_IDLE_AVAILABLE)) {
>>   		pr_info("PV spinlocks disabled\n");
>> @@ -82,7 +81,9 @@ void __init hv_init_spinlocks(void)
>>   
>>   static __init int hv_parse_nopvspin(char *arg)
>>   {
>> -	hv_pvspin = false;
>> +	pr_notice("\"hv_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");
>> +	if (x86_hyper_type == X86_HYPER_MS_HYPERV)
>> +		pvspin = false;
> Personal preference would be to keep the hv_pvspin variable and add the
> extra check in hv_init_spinlocks().

OK, will do that way. Thanks

Zhenzhong