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From: James Clark <james.clark@linaro.org>
To: Oliver Upton <oliver.upton@linux.dev>
Cc: kvmarm@lists.linux.dev,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	will@kernel.org, tabba@google.com, maz@kernel.org
Subject: Re: [bug report] KVM: arm64: BUG when reading kcore with kvm-arm.mode=protected
Date: Fri, 4 Oct 2024 16:41:10 +0100	[thread overview]
Message-ID: <cd1dda81-e23d-4f97-96b2-bf6e2002ea99@linaro.org> (raw)
In-Reply-To: <Zv1qeOOHjF0mv5Su@linux.dev>



On 02/10/2024 16:44, Oliver Upton wrote:
> +cc relevant folks
> 
> Hi James,
> 
> On Wed, Oct 02, 2024 at 02:23:32PM +0100, James Clark wrote:
>> Hi,
>>
>> I noticed this when running the Perf tests so I'm reporting it here (I don't
>> actually need kcore FWIW). I tested from 6.1 to 6.11 with the same results:
> 
> Yeah, this is (somewhat) intended behavior. By reading kcore you wind up
> reading from memory that isn't in a visible state for the host (e.g. hyp
> text).
> 
> Protected mode is very much a WIP, and is expected to be rough around the
> edges like this. Eventually the hypervisor will inject an abort into the
> host for disallowed memory accesses instead of tripping a BUG_ON(). We
> don't have that upstream right now.
> 

Thanks for the confirmation. I assumed as much but just wanted to be sure.


      reply	other threads:[~2024-10-04 17:10 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-02 13:23 [bug report] KVM: arm64: BUG when reading kcore with kvm-arm.mode=protected James Clark
2024-10-02 15:44 ` Oliver Upton
2024-10-04 15:41   ` James Clark [this message]

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