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Subject: Re: [PATCH v1 2/8] virtio: Add boundary checks to virtio ring
To:     Jason Wang <jasowang@redhat.com>, mst@redhat.com
Cc:     virtualization@lists.linux-foundation.org, hch@lst.de,
        m.szyprowski@samsung.com, robin.murphy@arm.com,
        iommu@lists.linux-foundation.org, x86@kernel.org,
        sathyanarayanan.kuppuswamy@linux.intel.com, jpoimboe@redhat.com,
        linux-kernel@vger.kernel.org
References: <20210603004133.4079390-1-ak@linux.intel.com>
 <20210603004133.4079390-3-ak@linux.intel.com>
 <4be00b3a-a15f-7fee-317b-ddabed3c1347@redhat.com>
From:   Andi Kleen <ak@linux.intel.com>
Message-ID: <ccf32bdc-a487-040b-5fe6-fcc8e71a57da@linux.intel.com>
Date:   Wed, 2 Jun 2021 19:18:20 -0700
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> It looks to me all the evils came from the fact that we depends on the 
> descriptor ring.
>
> So the checks in this patch could is unnecessary if we don't even read 
> from the descriptor ring which could be manipulated by the device.
>
> This is what my series tries to achieve:
>
> https://www.spinics.net/lists/kvm/msg241825.html

I would argue that you should boundary check in any case. It was always 
a bug to not have boundary checks in such a data structure with multiple 
users, trust or not.

But yes your patch series is interesting and definitely makes sense for 
TDX too.

Best would be to have both I guess, and always check the boundaries 
everywhere.

So what's the merge status of your series?

-Andi