On Thu, Mar 30, 2017 at 11:03:40AM -0400, Vlad Yasevich wrote:
> On 03/30/2017 10:53 AM, Dr. David Alan Gilbert wrote:
> > * Vlad Yasevich (vyase...@redhat.com) wrote:
> >> On 03/30/2017 04:24 AM, Dr. David Alan Gilbert wrote:
> >>> * Vladislav Yasevich (vyase...@redhat.com) wrote:
> >>>> virtio announcements seem to run on its own timer with it's own
> >>>> repetition loop and are invoked separately from qemu_announce_self.
> >>>> This patch consolidates announcements into a single location and
> >>>> allows other nics to provide it's own announcement capabilities, if
> >>>> necessary.
> >>>>
> >>>> This is also usefull in support of exposing qemu_announce_self through
> >>>> qmp/hmp.
> >>>>
> >>>> Signed-off-by: Vladislav Yasevich <vyase...@redhat.com>
> >>>> ---
> >>>> hw/net/virtio-net.c | 30 ++++++++----------------------
> >>>> include/hw/virtio/virtio-net.h | 2 --
> >>>> include/net/net.h | 2 ++
> >>>> migration/savevm.c | 6 ++++++
> >>>> 4 files changed, 16 insertions(+), 24 deletions(-)
> >>>>
> >>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> >>>> index c321680..6e9ce4f 100644
> >>>> --- a/hw/net/virtio-net.c
> >>>> +++ b/hw/net/virtio-net.c
> >>>> @@ -110,14 +110,16 @@ static bool virtio_net_started(VirtIONet *n,
> >>>> uint8_t status)
> >>>> (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
> >>>> }
> >>>>
> >>>> -static void virtio_net_announce_timer(void *opaque)
> >>>> +static void virtio_net_announce(NetClientState *nc)
> >>>> {
> >>>> - VirtIONet *n = opaque;
> >>>> + VirtIONet *n = qemu_get_nic_opaque(nc);
> >>>> VirtIODevice *vdev = VIRTIO_DEVICE(n);
> >>>>
> >>>> - n->announce_counter--;
> >>>> - n->status |= VIRTIO_NET_S_ANNOUNCE;
> >>>> - virtio_notify_config(vdev);
> >>>> + if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
> >>>> + virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
> >>>> + n->status |= VIRTIO_NET_S_ANNOUNCE;
> >>>> + virtio_notify_config(vdev);
> >>>> + }
> >>>> }
> >>>>
> >>>> static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> >>>> @@ -427,8 +429,6 @@ static void virtio_net_reset(VirtIODevice *vdev)
> >>>> n->nobcast = 0;
> >>>> /* multiqueue is disabled by default */
> >>>> n->curr_queues = 1;
> >>>> - timer_del(n->announce_timer);
> >>>> - n->announce_counter = 0;
> >>>> n->status &= ~VIRTIO_NET_S_ANNOUNCE;
> >>>>
> >>>> /* Flush any MAC and VLAN filter table state */
> >>>> @@ -868,11 +868,6 @@ static int virtio_net_handle_announce(VirtIONet *n,
> >>>> uint8_t cmd,
> >>>> if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
> >>>> n->status & VIRTIO_NET_S_ANNOUNCE) {
> >>>> n->status &= ~VIRTIO_NET_S_ANNOUNCE;
> >>>> - if (n->announce_counter) {
> >>>> - timer_mod(n->announce_timer,
> >>>> - qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
> >>>> - self_announce_delay(n->announce_counter));
> >>>> - }
> >>>> return VIRTIO_NET_OK;
> >>>> } else {
> >>>> return VIRTIO_NET_ERR;
> >>>> @@ -1609,12 +1604,6 @@ static int virtio_net_post_load_device(void
> >>>> *opaque, int version_id)
> >>>> qemu_get_subqueue(n->nic, i)->link_down = link_down;
> >>>> }
> >>>>
> >>>> - if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
> >>>> - virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
> >>>> - n->announce_counter = SELF_ANNOUNCE_ROUNDS;
> >>>> - timer_mod(n->announce_timer,
> >>>> qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL));
> >>>> - }
> >>>> -
> >>>> return 0;
> >>>> }
> >>>>
> >>>> @@ -1829,6 +1818,7 @@ static NetClientInfo net_virtio_info = {
> >>>> .receive = virtio_net_receive,
> >>>> .link_status_changed = virtio_net_set_link_status,
> >>>> .query_rx_filter = virtio_net_query_rxfilter,
> >>>> + .announce = virtio_net_announce,
> >>>> };
> >>>>
> >>>> static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int
> >>>> idx)
> >>>> @@ -1934,8 +1924,6 @@ static void virtio_net_device_realize(DeviceState
> >>>> *dev, Error **errp)
> >>>> qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
> >>>> memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
> >>>> n->status = VIRTIO_NET_S_LINK_UP;
> >>>> - n->announce_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
> >>>> - virtio_net_announce_timer, n);
> >>>>
> >>>> if (n->netclient_type) {
> >>>> /*
> >>>> @@ -1997,8 +1985,6 @@ static void
> >>>> virtio_net_device_unrealize(DeviceState *dev, Error **errp)
> >>>> virtio_net_del_queue(n, i);
> >>>> }
> >>>>
> >>>> - timer_del(n->announce_timer);
> >>>> - timer_free(n->announce_timer);
> >>>> g_free(n->vqs);
> >>>> qemu_del_nic(n->nic);
> >>>> virtio_cleanup(vdev);
> >>>> diff --git a/include/hw/virtio/virtio-net.h
> >>>> b/include/hw/virtio/virtio-net.h
> >>>> index 1eec9a2..0c597f4 100644
> >>>> --- a/include/hw/virtio/virtio-net.h
> >>>> +++ b/include/hw/virtio/virtio-net.h
> >>>> @@ -94,8 +94,6 @@ typedef struct VirtIONet {
> >>>> char *netclient_name;
> >>>> char *netclient_type;
> >>>> uint64_t curr_guest_offloads;
> >>>> - QEMUTimer *announce_timer;
> >>>> - int announce_counter;
> >>>> bool needs_vnet_hdr_swap;
> >>>> } VirtIONet;
> >>>>
> >>>> diff --git a/include/net/net.h b/include/net/net.h
> >>>> index 99b28d5..598f523 100644
> >>>> --- a/include/net/net.h
> >>>> +++ b/include/net/net.h
> >>>> @@ -64,6 +64,7 @@ typedef int (SetVnetLE)(NetClientState *, bool);
> >>>> typedef int (SetVnetBE)(NetClientState *, bool);
> >>>> typedef struct SocketReadState SocketReadState;
> >>>> typedef void (SocketReadStateFinalize)(SocketReadState *rs);
> >>>> +typedef void (NetAnnounce)(NetClientState *);
> >>>>
> >>>> typedef struct NetClientInfo {
> >>>> NetClientDriver type;
> >>>> @@ -84,6 +85,7 @@ typedef struct NetClientInfo {
> >>>> SetVnetHdrLen *set_vnet_hdr_len;
> >>>> SetVnetLE *set_vnet_le;
> >>>> SetVnetBE *set_vnet_be;
> >>>> + NetAnnounce *announce;
> >>>> } NetClientInfo;
> >>>>
> >>>> struct NetClientState {
> >>>> diff --git a/migration/savevm.c b/migration/savevm.c
> >>>> index 3b19a4a..5c1d8dc 100644
> >>>> --- a/migration/savevm.c
> >>>> +++ b/migration/savevm.c
> >>>> @@ -113,9 +113,15 @@ static void qemu_announce_self_iter(NICState *nic,
> >>>> void *opaque)
> >>>> int len;
> >>>>
> >>>> trace_qemu_announce_self_iter(qemu_ether_ntoa(&nic->conf->macaddr));
> >>>> +
> >>>> len = announce_self_create(buf, nic->conf->macaddr.a);
> >>>>
> >>>> qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
> >>>> +
> >>>> + /* if the NIC provides it's own announcement support, use it as
> >>>> well */
> >>>> + if (nic->ncs->info->announce) {
> >>>> + nic->ncs->info->announce(nic->ncs);
> >>>> + }
> >>>> }
> >>>
> >>> Combining them doesn't necessarily seem like a bad thing; but
> >>> it does change the timing quite a bit - at the moment the QEMU RARPs
> >>> are sent at the end of migration, while the Virtio ARPs are sent
> >>> when the guest starts running which is quite a bit later.
> >>>
> >>> In many ways the 'when the guest starts' is better, given that libvirt
> >>> etc has had a chance to reconfigure the networking, but I'm not that
> >>> sure if it's safe to move the existing one - I had considered *adding*
> >>> another shot of the current mechanism after the guest is started.
> >>>
> >>
> >> Yes, the timing of things have been giving me some issues, but I wanted to
> >> post
> >> this patch to get some comments just like this one..
> >>
> >> I've wondered why they qemu one happens before the guest starts running.
> >>
> >>> I certainly think it's wrong to do the virtio announce at the earlier
> >>> point.
> >>>
> >>
> >> I see.
> >
> > The problem with moving it earlier is that it won't really happen.
> > The guest wont be running at all at the earlier point so it wont consume
> > your requests to the guest to do the announce.
> >
> >
> >
> >>> See also Germano's thread of being able to retrigger the announce
> >>> at arbitrary points, and the series I posted a couple of days ago
> >>> to extend the length/timing of the announce.
> >>>
> >>
> >> That's kind of what prompted me to do try this. The issue with just
> >> exposing qemu_announce_self() is that RARPS just aren't enough in
> >> some cases (vlans, multicast). This attempts to add the callback
> >> like Jason mentioned, but then we get timer interactions between the
> >> virtio-net timers and qemu one.
> >
> > Yes, and I think it would be a good idea to add the virtio stuff
> > to germano's announces; however I don't think we can move those
> > announces earlier in the normal migration case.
> >
>
> So, I am taking a different approach. I am going to expose device specific
> announcement capabilities, and once that's done, the qmp API can directly
> tell the device to self-announce if it supports it, or tell qemu to announce
> itself in the old-fashioned method.
>
> That seems to provide the most flexibility. An additional thought is for the
> qmp
> command to optionally specify the number of announcement retries (like your
> set
> allows for migration).
>
> -vlad
It's worth thinking about whether qemu announcements should run
when VM is not running. It certainly exposes a bunch of theoretical
issues e.g. if you try to run the VM on another host at the same time.
Are there advantages in doing it like this?
> > Dave
> >
> >> -vlad
> >>
> >>> Dave
> >>>
> >>>> --
> >>>> 2.7.4
> >>>>
> >>>>
> >>> --
> >>> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> >>>
> >>
> > --
> > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> >
