Re: [dpdk-dev] [PATCH v5] vhost: fix async copy fail on multi-page buffers

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 7/29/20 4:04 AM, Patrick Fu wrote:
> Async copy fails when single ring buffer vector is splited on multiple
> physical pages. This happens because current hpa address translation
> function doesn't handle multi-page buffers. A new gpa to hpa address
> conversion function, which returns the hpa on the first hitting host
> pages, is implemented in this patch. Async data path recursively calls
> this new function to construct a multi-segments async copy descriptor
> for ring buffers crossing physical page boundaries.
> 
> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
> 
> Signed-off-by: Patrick Fu <patrick.fu@intel.com>
> ---
> v2:
>  - change commit message and title
>  - v1 patch used CPU to copy multi-page buffers; v2 patch split the
> copy into multiple async copy segments whenever possible
> 
> v3:
>  - added fixline
> 
> v4:
>  - fix miss translation of the gpa which is the same length with host
>    page size
> v5:
>  - combine redundant "if" statement in async_mbuf_to_desc()
> 
>  lib/librte_vhost/vhost.h      | 50 +++++++++++++++++++++++++++++++++++
>  lib/librte_vhost/virtio_net.c | 39 ++++++++++++++++-----------
>  2 files changed, 74 insertions(+), 15 deletions(-)

Thanks Patrick, it looks better to me now:
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Maxime