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Date:   Wed, 2 Jun 2021 15:16:12 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Praveen Kumar <kumarpraveen@linux.microsoft.com>
Cc:     Wei Liu <wei.liu@kernel.org>, linux-hyperv@vger.kernel.org,
        linux-kernel@vger.kernel.org, kys@microsoft.com,
        haiyangz@microsoft.com, sthemmin@microsoft.com,
        decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com,
        bp@alien8.de, nunodasneves@linux.microsoft.com,
        viremana@linux.microsoft.com, sunilmut@microsoft.com,
        Michael Kelley <mikelley@microsoft.com>
Subject: Re: [PATCH] x86/hyperv: LP creation with lp_index on same CPU-id
Message-ID: <20210602151612.7wz2ni4iyw7uzufm@liuwe-devbox-debian-v2>
References: <20210531074046.113452-1-kumarpraveen@linux.microsoft.com>
 <20210531105732.muzbpk4yksttsfwz@liuwe-devbox-debian-v2>
 <572da60e-714f-b207-a89e-6dc40209e2da@linux.microsoft.com>
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On Mon, May 31, 2021 at 04:31:04PM +0530, Praveen Kumar wrote:
> 
> 
> On 5/31/2021 4:27 PM, Wei Liu wrote:
> > On Mon, May 31, 2021 at 01:10:46PM +0530, Praveen Kumar wrote:
> >> The hypervisor expects the lp_index to be same as cpu-id during LP creation
> >> This fix correct the same, as cpu_physical_id can give different cpu-id.
> > 
> > Code looks fine to me, but the commit message can be made clearer.
> > 
> > """
> > The hypervisor expects the logical processor index to be the same as
> > CPU's id during logical processor creation. Using cpu_physical_id
> > confuses Microsoft Hypervisor's scheduler. That causes the root
> > partition not boot when core scheduler is used.
> > 
> > This patch removes the call to cpu_physical_id and uses the CPU index
> > directly for bringing up logical processor. This scheme works for both
> > classic scheduler and core scheduler.
> > 
> > Fixes: 333abaf5abb3 (x86/hyperv: implement and use hv_smp_prepare_cpus)
> > """
> > 
> > No action is required from you. If you are fine with this commit message
> > I can incorporate it and update the subject line when committing this
> > patch.
> > 
> 
> Thanks Wei for your comments. I'm fine with your inputs. Please go ahead. Thanks.

Pushed to hyperv-next. Thanks.