Re: [dpdk-stable] [PATCH v3 2/3] vhost: convert buffer addresses to GPA for logging

[Adrian Moreno <amorenoz@redhat.com>]

On 10/8/19 8:30 AM, Tiwei Bie wrote:
> On Fri, Sep 27, 2019 at 08:37:58PM +0200, Adrian Moreno wrote:
>> Note that the API facing rte_vhost_log_write is not modified.
>> So, make explicit that it expects the address in GPA space.
>>
>> Fixes: 69c90e98f483 ("vhost: enable IOMMU support")
>> Cc: maxime.coquelin@redhat.com
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
>> ---
>>  lib/librte_vhost/rte_vhost.h  |  2 +-
>>  lib/librte_vhost/vdpa.c       |  4 +++-
>>  lib/librte_vhost/vhost.c      | 21 +++++++++++++++++++++
>>  lib/librte_vhost/vhost.h      | 16 ++++++++++++++++
>>  lib/librte_vhost/virtio_net.c | 12 +++++++-----
>>  5 files changed, 48 insertions(+), 7 deletions(-)
>>
>> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
>> index 7fb172912..16c7e4243 100644
>> --- a/lib/librte_vhost/rte_vhost.h
>> +++ b/lib/librte_vhost/rte_vhost.h
>> @@ -265,7 +265,7 @@ rte_vhost_va_from_guest_pa(struct rte_vhost_memory *mem,
>>   * @param vid
>>   *  vhost device ID
>>   * @param addr
>> - *  the starting address for write
>> + *  the starting address for write (in guest physical address space)
>>   * @param len
>>   *  the length to write
>>   */
>> diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
>> index 8e45ce9f8..11fd5aede 100644
>> --- a/lib/librte_vhost/vdpa.c
>> +++ b/lib/librte_vhost/vdpa.c
>> @@ -201,7 +201,9 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
>>  				goto fail;
>>  			desc = desc_ring[desc_id];
>>  			if (desc.flags & VRING_DESC_F_WRITE)
>> -				vhost_log_write(dev, desc.addr, desc.len);
>> +				vhost_log_cache_write_iova(dev, vq,
>> +							   desc.addr,
>> +							   desc.len);
> 
> This will only log the dirty pages in cache.
You're right. Thanks for spotting it. I will change it in the next version.
> 
> 
>>  			desc_id = desc.next;
>>  		} while (desc.flags & VRING_DESC_F_NEXT);
>>  
>> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
>> index e57dda22f..78457a77c 100644
>> --- a/lib/librte_vhost/vhost.c
>> +++ b/lib/librte_vhost/vhost.c
>> @@ -200,6 +200,27 @@ __vhost_log_cache_write(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>  	}
>>  }
>>  
>> +void
>> +__vhost_log_cache_write_iova(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> +			     uint64_t iova, uint64_t len)
>> +{
>> +	uint64_t hva, gpa, map_len;
>> +	map_len = len;
>> +
>> +	hva = __vhost_iova_to_vva(dev, vq, iova, &map_len, VHOST_ACCESS_RW);
>> +	if (map_len != len) {
>> +		RTE_LOG(ERR, VHOST_CONFIG,
>> +			"Failed to write log for IOVA 0x%0lx."
> 
> PRIx64 should be used here, otherwise the build will be
> broken on i686.
> 
> It's better to add a space after '.'
Thank you. Will do.
> 
> 
>> +			"No IOTLB entry found\n",
>> +			iova);
>> +		return;
>> +	}
>> +
>> +	gpa = hva_to_gpa(dev, hva, len);
>> +	if (gpa)
>> +		__vhost_log_cache_write(dev, vq, gpa, len);
>> +}
>> +