* Peter Xu (pet...@redhat.com) wrote:
> On Fri, Feb 16, 2018 at 01:16:06PM +0000, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> >
> > Register the UFD that comes in as the response to the 'advise' method
> > with the postcopy code.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > ---
> > hw/virtio/vhost-user.c | 21 ++++++++++++++++++++-
> > migration/postcopy-ram.h | 2 +-
> > 2 files changed, 21 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index 4f59993baa..dd4eb50668 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -24,6 +24,7 @@
> > #include <sys/socket.h>
> > #include <sys/un.h>
> > #include <linux/vhost.h>
> > +#include <linux/userfaultfd.h>
>
> Why this line?
Actually, we don't need this until a few patches later in
'Resolve client address' where we pick apart the message
received from the kernel. I've moved it there.
> >
> > #define VHOST_MEMORY_MAX_NREGIONS 8
> > #define VHOST_USER_F_PROTOCOL_FEATURES 30
> > @@ -155,6 +156,7 @@ struct vhost_user {
> > CharBackend *chr;
> > int slave_fd;
> > NotifierWithReturn postcopy_notifier;
> > + struct PostCopyFD postcopy_fd;
> > };
> >
> > static bool ioeventfd_enabled(void)
> > @@ -780,6 +782,17 @@ out:
> > return ret;
> > }
> >
> > +/*
> > + * Called back from the postcopy fault thread when a fault is received on
> > our
> > + * ufd.
> > + * TODO: This is Linux specific
> > + */
> > +static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
> > + void *ufd)
> > +{
> > + return 0;
> > +}
> > +
> > /*
> > * Called at the start of an inbound postcopy on reception of the
> > * 'advise' command.
> > @@ -819,8 +832,14 @@ static int vhost_user_postcopy_advise(struct vhost_dev
> > *dev, Error **errp)
> > error_setg(errp, "%s: Failed to get ufd", __func__);
> > return -1;
> > }
> > + fcntl(ufd, F_SETFL, O_NONBLOCK);
>
> Only curious: would it work even without this line?
Probably; it's used in a poll() anyway, so it should be fine.
> >
> > - /* TODO: register ufd with userfault thread */
> > + /* register ufd with userfault thread */
> > + u->postcopy_fd.fd = ufd;
> > + u->postcopy_fd.data = dev;
> > + u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
> > + u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
> > + postcopy_register_shared_ufd(&u->postcopy_fd);
> > return 0;
> > }
> >
> > diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
> > index 4bda5aa509..23efbdf346 100644
> > --- a/migration/postcopy-ram.h
> > +++ b/migration/postcopy-ram.h
> > @@ -153,7 +153,7 @@ struct PostCopyFD {
> > /* Handler to be called whenever we get a poll event */
> > pcfdhandler handler;
> > /* A string to use in error messages */
> > - char *idstr;
> > + const char *idstr;
>
> Move to previous patch?
Done.
Dave
> > };
> >
> > /* Register a userfaultfd owned by an external process for
> > --
> > 2.14.3
> >
>
> --
> Peter Xu
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
