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Date:   Thu, 18 Jul 2019 09:56:16 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Dexuan Cui <decui@microsoft.com>
cc:     Haiyang Zhang <haiyangz@microsoft.com>,
        KY Srinivasan <kys@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Sasha Levin <Alexander.Levin@microsoft.com>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        Michael Kelley <mikelley@microsoft.com>,
        Long Li <longli@microsoft.com>, vkuznets <vkuznets@redhat.com>,
        Ingo Molnar <mingo@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Borislav Petkov <bp@alien8.de>,
        "x86@kernel.org" <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>,
        "driverdev-devel@linuxdriverproject.org" 
        <driverdev-devel@linuxdriverproject.org>,
        "olaf@aepfle.de" <olaf@aepfle.de>,
        "apw@canonical.com" <apw@canonical.com>,
        "jasowang@redhat.com" <jasowang@redhat.com>
Subject: RE: [PATCH] x86/hyper-v: Zero out the VP assist page to fix CPU
 offlining
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On Thu, 18 Jul 2019, Dexuan Cui wrote:
> 
> The concept of the "overlay page" seems weird, and frankly speaking, 
> I don't really understand why the Hyper-V guys invented it, but as far
> as this patch here is concerned, I think the patch is safe and it can
> indeed fix the CPU offlining issue I described.

Then this needs some really good explanation and in the change log because
that's really obscure behaviour.

Thanks,

	tglx