linux-kernel - Re: [PATCH v2] x86/mce: fix wrong no-return-ip logic in do_machine

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Message-ID: <20210222180819.3998fe33@alex-virtual-machine>
Date:   Mon, 22 Feb 2021 18:08:19 +0800
From:   Aili Yao <yaoaili@...gsoft.com>
To:     Borislav Petkov <bp@...en8.de>
CC:     <tony.luck@...el.com>, <mingo@...hat.com>, <tglx@...utronix.de>,
        <hpa@...or.com>, <x86@...nel.org>, <linux-edac@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <yangfeng1@...gsoft.com>
Subject: Re: [PATCH v2] x86/mce: fix wrong no-return-ip logic in
 do_machine_check()

On Mon, 22 Feb 2021 11:03:56 +0100
Borislav Petkov <bp@...en8.de> wrote:

> On Mon, Feb 22, 2021 at 05:31:09PM +0800, Aili Yao wrote:
> > you can inject a memory UE to a VM, it should always be MCG_STATUS_RIPV 0.  
> 
> So the signature you injected is not something the hardware would
> generate - you just didn't set MCG_STATUS_RIPV.
> 
> If so, why should the code handle invalid signatures which the harware
> cannot generate?
> 

So why would intel provide this MCG_STATUS_RIPV flag, it's better to remove it as it will
never be set, and all the related logic for this flag is really needed ?