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From: Ingo Molnar <mingo@kernel.org>
To: Bharata B Rao <bharata@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
	linux-kernel@vger.kernel.org, tglx@linutronix.de,
	mingo@redhat.com, x86@kernel.org, dave.hansen@linux.intel.com,
	nikunj@amd.com, hpa@zytor.com, Abraham.Shaju@amd.com
Subject: Re: [RFC FIX PATCH] x86/e820: Stop kernel boot when RAM resource reservation fails
Date: Thu, 4 Aug 2022 11:46:35 +0200	[thread overview]
Message-ID: <YuuVezQMK/ytzMTe@gmail.com> (raw)
In-Reply-To: <24ccd22f-6708-3265-4012-66f01108ff22@amd.com>


* Bharata B Rao <bharata@amd.com> wrote:

> On 7/18/2022 8:37 PM, Borislav Petkov wrote:
> > 
> > I betcha you can generate a lot of "kernel bugs" with weird qemu
> > options. If it is not a real use case, nobody cares.
> 
> I see that we will hit this problem by default when starting
> a guest with 1T or more memory using QEMU.
> 
> > 
> > And even if it were a real use case, panicking the machine is not the
> > right fix.
> 
> I couldn't see a clean exit/recovery option in 
> setup_arch()->e820__reserve_resources() where this happens. Any 
> suggestions?

I'd emit a low impact, non-fatal WARN()ing to make sure users aren't silent 
victims of an easily detectable firmware (Qemu) misconfiguration.

Thanks,

	Ingo

      parent reply	other threads:[~2022-08-04  9:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-18  8:58 [RFC FIX PATCH] x86/e820: Stop kernel boot when RAM resource reservation fails Bharata B Rao
2022-07-18 10:42 ` Boris Petkov
2022-07-18 14:54   ` Bharata B Rao
2022-07-18 15:07     ` Borislav Petkov
2022-07-19  4:15       ` Bharata B Rao
2022-07-19 17:12         ` Sean Christopherson
2022-08-04  9:46         ` Ingo Molnar [this message]

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