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

[Tiwei Bie <tiwei.bie@intel.com>]

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.


>  			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 '.'


> +			"No IOTLB entry found\n",
> +			iova);
> +		return;
> +	}
> +
> +	gpa = hva_to_gpa(dev, hva, len);
> +	if (gpa)
> +		__vhost_log_cache_write(dev, vq, gpa, len);
> +}
> +