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Date:   Wed, 24 May 2023 22:33:10 +0200
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Peter Zijlstra" <peterz@infradead.org>,
        "Naresh Kamboju" <naresh.kamboju@linaro.org>
Cc:     "open list" <linux-kernel@vger.kernel.org>,
        linux-stable <stable@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>, "LTP List" <ltp@lists.linux.it>,
        lkft-triage@lists.linaro.org, "X86 ML" <x86@kernel.org>,
        "Thomas Gleixner" <tglx@linutronix.de>,
        "Andy Lutomirski" <luto@kernel.org>,
        "Ingo Molnar" <mingo@redhat.com>,
        "Dave Hansen" <dave.hansen@linux.intel.com>,
        "Andrew Morton" <akpm@linux-foundation.org>,
        "Dan Carpenter" <dan.carpenter@linaro.org>,
        "Anders Roxell" <anders.roxell@linaro.org>
Subject: Re: qemu-x86_64 compat: LTP: controllers: RIP: 0010:__alloc_pages
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On Wed, May 24, 2023, at 19:54, Peter Zijlstra wrote:
> On Wed, May 24, 2023 at 09:39:50PM +0530, Naresh Kamboju wrote:
>> FYI,
>> These are running in AWS cloud as qemu-i386 and qemu-x86_64.
>
> Are these hosted on x86 and using KVM or are they hosted on Graviton and
> using TCG x86 ?
>
> Supposedly TCG x86 is known 'funny' and if that's what you're using it
> would be very good to confirm the problem on x86 hardware.

Even on x86 cloud instances you are likely to run with TCG if
the host does not support nested virtualization. So the question
really is what specific cloud instance type this was running
on, and if KVM was actually used or not.  From what I could
find on the web, Amazon EC2 only supports KVM guests inside of
bare-metal instances but not any of the normal virtualized ones,
while other providers using KVM (Google, Microsoft, ...) do support
nested guests.

      Arnd