linux-kernel - Re: [PATCH] hyperv: root partition faults writing to VP ASSIST MSR PAGE

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Message-ID: <20210720133514.lurmus2lgffcldnq@liuwe-devbox-debian-v2>
Date:   Tue, 20 Jul 2021 13:35:14 +0000
From:   Wei Liu <wei.liu@...nel.org>
To:     Praveen Kumar <kumarpraveen@...ux.microsoft.com>
Cc:     Wei Liu <wei.liu@...nel.org>, linux-hyperv@...r.kernel.org,
        linux-kernel@...r.kernel.org, kys@...rosoft.com,
        haiyangz@...rosoft.com, sthemmin@...rosoft.com,
        decui@...rosoft.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, x86@...nel.org, hpa@...or.com,
        viremana@...ux.microsoft.com, sunilmut@...rosoft.com,
        nunodasneves@...ux.microsoft.com
Subject: Re: [PATCH] hyperv: root partition faults writing to VP ASSIST MSR
 PAGE

On Tue, Jul 20, 2021 at 06:55:56PM +0530, Praveen Kumar wrote:
[...]
> > 
> >> +	if (hv_root_partition &&
> >> +	    ms_hyperv.features & HV_MSR_APIC_ACCESS_AVAILABLE) {
> > 
> > Is HV_MSR_APIC_ACCESS_AVAILABLE a root only flag? Shouldn't non-root
> > kernel check this too?
> 
> Yes, you are right. Will update this in v2. thanks.

Please split adding this check to its own patch.

Ideally one patch only does one thing.

Wei.

> 
> > 
> > Wei.
> > 
> 
> Regards,
> 
> ~Praveen.