Re: [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size

From: Marc Zyngier <maz@kernel.org>
To: Andrew Jones <drjones@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Will Deacon <will@kernel.org>, Eric Auger <eric.auger@redhat.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com, stable@vger.kernel.org
Subject: Re: [PATCH v3 2/2] KVM: arm64: Fix exclusive limit for IPA size
Date: Fri, 12 Mar 2021 15:44:38 +0000	[thread overview]
Message-ID: <7ce8f57d2bcc19a77993fc01845ac6cb@kernel.org> (raw)
In-Reply-To: <20210311111500.uqy4lolxtp7t4xd4@kamzik.brq.redhat.com>

On 2021-03-11 11:15, Andrew Jones wrote:
> On Thu, Mar 11, 2021 at 10:00:16AM +0000, Marc Zyngier wrote:
>> When registering a memslot, we check the size and location of that
>> memslot against the IPA size to ensure that we can provide guest
>> access to the whole of the memory.
>> 
>> Unfortunately, this check rejects memslot that end-up at the exact
>> limit of the addressing capability for a given IPA size. For example,
>> it refuses the creation of a 2GB memslot at 0x8000000 with a 32bit
>> IPA space.
>> 
>> Fix it by relaxing the check to accept a memslot reaching the
>> limit of the IPA space.
>> 
>> Fixes: e55cac5bf2a9 ("kvm: arm/arm64: Prepare for VM specific stage2 
>> translations")
> 
> Isn't this actually fixing commit c3058d5da222 ("arm/arm64: KVM: Ensure
> memslots are within KVM_PHYS_SIZE") ?

Ah, yes, that's indeed better (more backport work... ;-)

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...