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

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

On Tue, Oct 08, 2019 at 09:43:48AM +0200, Maxime Coquelin wrote:
> On 10/8/19 9:38 AM, Adrian Moreno wrote:
> > 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",
> 
> I personally prefer not to split error messages even it is is slightly
> above 80 chars. It makes grepping for error messages easier.

+1


> 
> >>> +			iova);
> >>> +		return;
> >>> +	}
> >>> +
> >>> +	gpa = hva_to_gpa(dev, hva, len);
> >>> +	if (gpa)
> >>> +		__vhost_log_cache_write(dev, vq, gpa, len);
> >>> +}
> >>> +
> >