Re: [dpdk-dev] [PATCH 06/12] vhost: register new regions with userfaultfd

[Alejandro Lucero <alejandro.lucero@netronome.com>]

On Wed, Sep 26, 2018 at 8:28 AM Maxime Coquelin <maxime.coquelin@redhat.com>
wrote:

> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/librte_vhost/vhost_user.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index d9ef5bca8..cbbfbdf00 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -928,6 +928,28 @@ vhost_user_set_mem_table(struct virtio_net **pdev,
> struct VhostUserMsg *pmsg)
>                         mmap_size,
>                         alignment,
>                         mmap_offset);
> +
> +               if (dev->postcopy_listening) {
> +                       struct uffdio_register reg_struct;
> +
> +                       reg_struct.range.start =
> (uint64_t)(uintptr_t)mmap_addr;
> +                       reg_struct.range.len = mmap_size;
> +                       reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
> +
> +                       if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
> +                                               &reg_struct)) {
> +                               RTE_LOG(ERR, VHOST_CONFIG,
> +                                               "Failed to register ufd
> for region %d: (ufd = %d) %s\n",
> +                                               i, dev->postcopy_ufd,
> +                                               strerror(errno));
> +                               continue;
>

is it not a registration error a serious problem for supporting migration
properly?


> +                       }
> +                       RTE_LOG(INFO, VHOST_CONFIG,
> +                                       "\t userfaultfd registered for
> range : %llx - %llx\n",
> +                                       reg_struct.range.start,
> +                                       reg_struct.range.start +
> +                                       reg_struct.range.len - 1);
> +               }
>         }
>
>         for (i = 0; i < dev->nr_vring; i++) {
> --
> 2.17.1
>
>