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To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
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From: Maxime Coquelin <maxime.coquelin@redhat.com>
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Date: Fri, 23 Sep 2016 09:33:01 +0200
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 (mx1.redhat.com [10.5.110.27]); Fri, 23 Sep 2016 07:33:04 +0000 (UTC)
Subject: Re: [dpdk-dev] [PATCH v2] vhost: Add indirect descriptors support
	to the TX path
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On 09/23/2016 09:29 AM, Yuanhan Liu wrote:
> On Fri, Sep 23, 2016 at 09:16:49AM +0200, Maxime Coquelin wrote:
>> +		if (vq->desc[desc_indexes[i]].flags & VRING_DESC_F_INDIRECT) {
>> +			if (unlikely(!(dev->features &
>> +					(1ULL << VIRTIO_RING_F_INDIRECT_DESC)))) {
>> +				RTE_LOG(ERR, VHOST_DATA,
>> +						"Indirect desc but feature not negotiated.\n");
>> +				break;
>> +			}
>
> I thought the alignment we got before was to follow linux kernel: check
> nested indirect only?
Right... I did the opposite..
Fixing this right now.

>
>> +
>> +			desc = (struct vring_desc *)gpa_to_vva(dev,
>> +					vq->desc[desc_indexes[i]].addr);
>
> I think we should check the desc addr here. Otherwise we may crash here
> if a malicious guest fills some bad addresses.
Good point!

Thanks,
Maxime
>
> 	--yliu
>