On Wed, Oct 20, 2021 at 2:19 PM Zhang, Chen <chen.zh...@intel.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Jason Wang <jasow...@redhat.com>
> > Sent: Wednesday, October 20, 2021 11:13 AM
> > To: Zhang, Chen <chen.zh...@intel.com>
> > Cc: Eric Blake <ebl...@redhat.com>; Markus Armbruster
> > <arm...@redhat.com>; qemu-dev <qemu-devel@nongnu.org>; Li Zhijian
> > <lizhij...@cn.fujitsu.com>; Lukas Straub <lukasstra...@web.de>
> > Subject: Re: [PATCH V3] net/colo: check vnet_hdr_support flag when using
> > virtio-net
> >
> > On Wed, Oct 20, 2021 at 10:53 AM Zhang, Chen <chen.zh...@intel.com>
> > wrote:
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Jason Wang <jasow...@redhat.com>
> > > > Sent: Tuesday, October 19, 2021 3:39 PM
> > > > To: Zhang, Chen <chen.zh...@intel.com>; Eric Blake
> > > > <ebl...@redhat.com>; Markus Armbruster <arm...@redhat.com>
> > > > Cc: qemu-dev <qemu-devel@nongnu.org>; Li Zhijian
> > > > <lizhij...@cn.fujitsu.com>; Lukas Straub <lukasstra...@web.de>; Tao
> > > > Xu <tao3...@intel.com>
> > > > Subject: Re: [PATCH V3] net/colo: check vnet_hdr_support flag when
> > > > using virtio-net
> > > >
> > > >
> > > > 在 2021/9/18 上午10:04, Zhang Chen 写道:
> > > > > When COLO use only one vnet_hdr_support parameter between COLO
> > > > network
> > > > > filter(filter-mirror, filter-redirector or filter-rewriter and
> > > > > colo-compare, packet will not be parsed correctly. Acquire network
> > > > > driver related to COLO, if it is nirtio-net,
> > > >
> > > >
> > > > Typo.
> > >
> > > Oh~ will fix in next version.
> > >
> > > >
> > > >
> > > > > check vnet_hdr_support flag of COLO network filter and colo-compare.
> > > > >
> > > > > Signed-off-by: Tao Xu <tao3...@intel.com>
> > > > > Signed-off-by: Zhang Chen <chen.zh...@intel.com>
> > > > > ---
> > > > >
> > > > > Changelog:
> > > > > v3:
> > > > > Fix some typos.
> > > > > Rebased for Qemu 6.2.
> > > > >
> > > > > v2:
> > > > > Detect virtio-net driver and apply vnet_hdr_support
> > > > > automatically. (Jason)
> > > > > ---
> > > > > net/colo-compare.c | 57
> > > > +++++++++++++++++++++++++++++++++++++++++++
> > > > > net/colo.c | 20 +++++++++++++++
> > > > > net/colo.h | 4 +++
> > > > > net/filter-mirror.c | 21 ++++++++++++++++
> > > > > net/filter-rewriter.c | 10 ++++++++
> > > > > qapi/qom.json | 6 +++++
> > > > > qemu-options.hx | 6 +++--
> > > > > 7 files changed, 122 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/net/colo-compare.c b/net/colo-compare.c index
> > > > > b100e7b51f..870bd05a41 100644
> > > > > --- a/net/colo-compare.c
> > > > > +++ b/net/colo-compare.c
> > > > > @@ -110,6 +110,7 @@ struct CompareState {
> > > > > char *sec_indev;
> > > > > char *outdev;
> > > > > char *notify_dev;
> > > > > + char *netdev;
> > > > > CharBackend chr_pri_in;
> > > > > CharBackend chr_sec_in;
> > > > > CharBackend chr_out;
> > > > > @@ -838,6 +839,28 @@ static int compare_chr_can_read(void *opaque)
> > > > > return COMPARE_READ_LEN_MAX;
> > > > > }
> > > > >
> > > > > +static int colo_set_default_netdev(void *opaque, QemuOpts *opts,
> > > > > +Error **errp) {
> > > > > + const char *colo_obj_type, *netdev_from_filter;
> > > > > + char **netdev = (char **)opaque;
> > > > > +
> > > > > + colo_obj_type = qemu_opt_get(opts, "qom-type");
> > > > > +
> > > > > + if (colo_obj_type &&
> > > > > + (strcmp(colo_obj_type, "filter-mirror") == 0 ||
> > > > > + strcmp(colo_obj_type, "filter-redirector") == 0 ||
> > > > > + strcmp(colo_obj_type, "filter-rewriter") == 0)) {
> > > > > + netdev_from_filter = qemu_opt_get(opts, "netdev");
> > > > > + if (*netdev == NULL) {
> > > > > + *netdev = g_strdup(netdev_from_filter);
> > > > > + } else if (strcmp(*netdev, netdev_from_filter) != 0) {
> > > > > + warn_report("%s is using a different netdev from other
> > > > > COLO "
> > > > > + "component", colo_obj_type);
> > > > > + }
> > > > > + }
> > > > > + return 0;
> > > > > +}
> > > > > +
> > > > > /*
> > > > > * Called from the main thread on the primary for packets
> > > > > * arriving over the socket from the primary.
> > > > > @@ -1050,6 +1073,21 @@ static void compare_set_vnet_hdr(Object
> > *obj,
> > > > > s->vnet_hdr = value;
> > > > > }
> > > > >
> > > > > +static char *compare_get_netdev(Object *obj, Error **errp) {
> > > > > + CompareState *s = COLO_COMPARE(obj);
> > > > > +
> > > > > + return g_strdup(s->netdev);
> > > > > +}
> > > > > +
> > > > > +static void compare_set_netdev(Object *obj, const char *value,
> > > > > +Error
> > > > > +**errp) {
> > > > > + CompareState *s = COLO_COMPARE(obj);
> > > > > +
> > > > > + g_free(s->netdev);
> > > > > + s->netdev = g_strdup(value);
> > > > > +}
> > > > > +
> > > > > static char *compare_get_notify_dev(Object *obj, Error **errp)
> > > > > {
> > > > > CompareState *s = COLO_COMPARE(obj); @@ -1274,6 +1312,12
> > @@
> > > > > static void colo_compare_complete(UserCreatable *uc, Error **errp)
> > > > > max_queue_size = MAX_QUEUE_SIZE;
> > > > > }
> > > > >
> > > > > + if (!s->netdev) {
> > > > > + /* Set default netdev as the first colo netfilter found */
> > > > > + qemu_opts_foreach(qemu_find_opts("object"),
> > > > > + colo_set_default_netdev, &s->netdev, NULL);
> > > > > + }
> > > > > +
> > > > > if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
> > > > > !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
> > > > > return;
> > > > > @@ -1289,6 +1333,16 @@ static void
> > > > colo_compare_complete(UserCreatable *uc, Error **errp)
> > > > > return;
> > > > > }
> > > > >
> > > > > + if (!s->vnet_hdr &&
> > > > > + qemu_opts_foreach(qemu_find_opts("device"),
> > > > > + vnet_driver_check, s->netdev, NULL)) {
> > > > > + /*
> > > > > + * colo compare needs 'vnet_hdr_support' when it works on
> > virtio-net,
> > > > > + * add 'vnet_hdr_support' automatically
> > > > > + */
> > > > > + s->vnet_hdr = true;
> > > > > + }
> > > > > +
> > > > > net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s-
> > >vnet_hdr);
> > > > > net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize,
> > > > > s->vnet_hdr);
> > > > >
> > > > > @@ -1400,6 +1454,9 @@ static void colo_compare_init(Object *obj)
> > > > > s->vnet_hdr = false;
> > > > > object_property_add_bool(obj, "vnet_hdr_support",
> > > > compare_get_vnet_hdr,
> > > > > compare_set_vnet_hdr);
> > > > > + /* colo compare can't varify that netdev is correct */
> > > > > + object_property_add_str(obj, "netdev", compare_get_netdev,
> > > > > + compare_set_netdev);
> > > > > }
> > > > >
> > > > > void colo_compare_cleanup(void)
> > > > > diff --git a/net/colo.c b/net/colo.c index 3a3e6e89a0..4a03780f45
> > > > > 100644
> > > > > --- a/net/colo.c
> > > > > +++ b/net/colo.c
> > > > > @@ -243,3 +243,23 @@ bool connection_has_tracked(GHashTable
> > > > > *connection_track_table,
> > > > >
> > > > > return conn ? true : false;
> > > > > }
> > > > > +
> > > > > +/* check the network driver related to COLO, return 1 if it is
> > > > > +virtio-net */ int vnet_driver_check(void *opaque, QemuOpts *opts,
> > > > > +Error **errp) {
> > > > > + const char *driver_type, *netdev_from_driver;
> > > > > + char *netdev_from_filter = (char *)opaque;
> > > > > +
> > > > > + driver_type = qemu_opt_get(opts, "driver");
> > > > > + netdev_from_driver = qemu_opt_get(opts, "netdev");
> > > > > +
> > > > > + if (!driver_type || !netdev_from_driver || !netdev_from_filter) {
> > > > > + return 0;
> > > > > + }
> > > > > +
> > > > > + if (g_str_has_prefix(driver_type, "virtio-net") &&
> > > > > + strcmp(netdev_from_driver, netdev_from_filter) == 0) {
> > > > > + return 1;
> > > > > + }
> > > > > + return 0;
> > > > > +}
> > > > > diff --git a/net/colo.h b/net/colo.h index d91cd245c4..d401fc76b6
> > > > > 100644
> > > > > --- a/net/colo.h
> > > > > +++ b/net/colo.h
> > > > > @@ -18,6 +18,9 @@
> > > > > #include "qemu/jhash.h"
> > > > > #include "qemu/timer.h"
> > > > > #include "net/eth.h"
> > > > > +#include "qemu/option.h"
> > > > > +#include "qemu/option_int.h"
> > > > > +#include "qemu/config-file.h"
> > > > >
> > > > > #define HASHTABLE_MAX_SIZE 16384
> > > > >
> > > > > @@ -104,5 +107,6 @@ Packet *packet_new(const void *data, int size,
> > > > > int
> > > > vnet_hdr_len);
> > > > > Packet *packet_new_nocopy(void *data, int size, int vnet_hdr_len);
> > > > > void packet_destroy(void *opaque, void *user_data);
> > > > > void packet_destroy_partial(void *opaque, void *user_data);
> > > > > +int vnet_driver_check(void *opaque, QemuOpts *opts, Error
> > > > > +**errp);
> > > > >
> > > > > #endif /* NET_COLO_H */
> > > > > diff --git a/net/filter-mirror.c b/net/filter-mirror.c index
> > > > > f20240cc9f..69ca9c9839 100644
> > > > > --- a/net/filter-mirror.c
> > > > > +++ b/net/filter-mirror.c
> > > > > @@ -12,6 +12,7 @@
> > > > > #include "qemu/osdep.h"
> > > > > #include "net/filter.h"
> > > > > #include "net/net.h"
> > > > > +#include "net/colo.h"
> > > > > #include "qapi/error.h"
> > > > > #include "qom/object.h"
> > > > > #include "qemu/main-loop.h"
> > > > > @@ -224,6 +225,16 @@ static void
> > > > > filter_mirror_setup(NetFilterState *nf,
> > > > Error **errp)
> > > > > return;
> > > > > }
> > > > >
> > > > > + if (!s->vnet_hdr &&
> > > > > + qemu_opts_foreach(qemu_find_opts("device"),
> > > > > + vnet_driver_check, nf->netdev_id, NULL)) {
> > > > > + /*
> > > > > + * filter mirror needs 'vnet_hdr_support' when colo filter
> > > > > modules
> > > > > + * work on virtio-net, add 'vnet_hdr_support' automatically
> > > > > + */
> > > > > + s->vnet_hdr = true;
> > > > > + }
> > > > > +
> > > > > qemu_chr_fe_init(&s->chr_out, chr, errp);
> > > > > }
> > > > >
> > > > > @@ -252,6 +263,16 @@ static void
> > > > > filter_redirector_setup(NetFilterState
> > > > *nf, Error **errp)
> > > > > }
> > > > > }
> > > > >
> > > > > + if (!s->vnet_hdr &&
> > > > > + qemu_opts_foreach(qemu_find_opts("device"),
> > > > > + vnet_driver_check, nf->netdev_id, NULL)) {
> > > > > + /*
> > > > > + * filter redirector needs 'vnet_hdr_support' when colo
> > > > > filter
> > modules
> > > > > + * work on virtio-net, add 'vnet_hdr_support' automatically
> > > > > + */
> > > > > + s->vnet_hdr = true;
> > > > > + }
> > > > > +
> > > > > net_socket_rs_init(&s->rs, redirector_rs_finalize,
> > > > > s->vnet_hdr);
> > > > >
> > > > > if (s->indev) {
> > > > > diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c index
> > > > > cb3a96cde1..637ef4ce71 100644
> > > > > --- a/net/filter-rewriter.c
> > > > > +++ b/net/filter-rewriter.c
> > > > > @@ -388,6 +388,16 @@ static void
> > > > > colo_rewriter_setup(NetFilterState *nf,
> > > > Error **errp)
> > > > > {
> > > > > RewriterState *s = FILTER_REWRITER(nf);
> > > > >
> > > > > + if (!s->vnet_hdr &&
> > > > > + qemu_opts_foreach(qemu_find_opts("device"),
> > > > > + vnet_driver_check, nf->netdev_id, NULL)) {
> > > > > + /*
> > > > > + * filter rewriter needs 'vnet_hdr_support' when colo filter
> > modules
> > > > > + * work on virtio-net, add 'vnet_hdr_support' automatically
> > > > > + */
> > > > > + s->vnet_hdr = true;
> > > > > + }
> > > > > +
> > > > > s->connection_track_table =
> > > > g_hash_table_new_full(connection_key_hash,
> > > > >
> > > > > connection_key_equal,
> > > > > g_free,
> > > > > diff --git a/qapi/qom.json b/qapi/qom.json index
> > > > > a25616bc7a..5760107160
> > > > > 100644
> > > > > --- a/qapi/qom.json
> > > > > +++ b/qapi/qom.json
> > > > > @@ -241,6 +241,11 @@
> > > > > # @notify_dev: name of the character device backend to be used
> > > > > to
> > > > communicate
> > > > > # with the remote colo-frame (only for Xen COLO)
> > > > > #
> > > > > +# @netdev: id of the network device backend to colo-compare.
> > Although
> > > > > +# colo-compare doesn't depend on network device directly,
> > > > > this
> > > > > +# parameter helps colo-compare know what network driver it
> > > > > is
> > > > > +# working on.(since 6.2)
> > > >
> > > >
> > > > This looks kind of not elegant. We don't want to couple COLO with
> > > > netdev.
> > > >
> > > > I wonder if we can do this without adding netdev.
> > >
> > > Yes, current COLO is not bind to netdev, but here we want to auto fix
> > configuration issue.
> >
> > If my memory is correct, the current design allows an external comparing
> > module to work.
>
> Yes, this netdev used by identify a series of comparing modules (include
> filters).
>
> >
> > > To avoid wrong setting other non-colo related existing filter, COLO need
> > know the colo-effect netdev to setup.
> > > And this parameter is optional, this patch will setup default colo-effect
> > netdev in colo_set_default_netdev().
> > > Or any good idea?
> >
> > How about
> >
> > 1) adding a handshake in the protocol before receiving packets or
> > 2) add a header to the payload to show if it contains a vnet header or
> > 3) go back to let mgmt set vnet_hdr=on/off (looks like the first proposal
> > but
> > it avoids the coupling).
>
> Current code already have a header to the payload to show the vnet header(in
> net/filter-mirror.c filter_send()).
> But the vnet_hdr_len is not necessary:
> Disabled vnet_hdr payload:
> 1. size ---> 2. Real network payload.
> Enbaled vnet_hdr payload:
> 1. size ---> 2. Vnet_hdr_len ----> 3. Real network payload.
>
> It looks we can define the vnet_hdr_len as necessary part of protocol.
> If no vnet_hdr, we set the vnet_hdr_len to 0.
> 1. size ---> 2. Vnet_hdr_len ----> 3. Real network payload.
>
> How about this proposal?
I think it should work.
Thanks
>
> Thanks
> Chen
>
>
> >
> > Thanks
> >
> > >
> > > Thanks
> > > Chen
> > >
> > > >
> > > > Thanks
> > > >
> > > >
> > > > > +#
> > > > > # @compare_timeout: the maximum time to hold a packet from
> > > > @primary_in for
> > > > > # comparison with an incoming packet on
> > > > > @secondary_in in
> > > > > # milliseconds (default: 3000)
> > > > > @@ -264,6 +269,7 @@
> > > > > 'outdev': 'str',
> > > > > 'iothread': 'str',
> > > > > '*notify_dev': 'str',
> > > > > + '*netdev': 'str',
> > > > > '*compare_timeout': 'uint64',
> > > > > '*expired_scan_cycle': 'uint32',
> > > > > '*max_queue_size': 'uint32', diff --git
> > > > > a/qemu-options.hx b/qemu-options.hx index 8f603cc7e6..250937fbbf
> > > > > 100644
> > > > > --- a/qemu-options.hx
> > > > > +++ b/qemu-options.hx
> > > > > @@ -4964,12 +4964,14 @@ SRST
> > > > > stored. The file format is libpcap, so it can be analyzed
> > > > > with
> > > > > tools such as tcpdump or Wireshark.
> > > > >
> > > > > - ``-object colo-
> > > >
> > compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=cha
> > > > rd
> > > > evid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout
> > > > =@
> > > >
> > var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
> > > > > + ``-object
> > > > > + colo-
> > > > compare,id=id,primary_in=chardevid,secondary_in=chardevid,outde
> > > > > + v=chardevid,iothread=id[,netdev=netdevid][,vnet_hdr_support][,no
> > > > > + tify
> > > > > +
> > > >
> > _dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,
> > > > m
> > > > > + ax_queue_size=@var{size}]``
> > > > > Colo-compare gets packet from primary\_in chardevid and
> > > > > secondary\_in, then compare whether the payload of primary
> > packet
> > > > > and secondary packet are the same. If same, it will output
> > > > > primary packet to out\_dev, else it will notify
> > > > > COLO-framework to
> > do
> > > > > - checkpoint and send primary packet to out\_dev. In order to
> > > > > + checkpoint and send primary packet to out\_dev. Although
> > > > > + colo-
> > > > compare
> > > > > + does not depend on network device directly, netdevid helps
> > > > > + colo-compare know what network driver it is working on.
> > > > > + In order to
> > > > > improve efficiency, we need to put the task of comparison in
> > > > > another iothread. If it has the vnet\_hdr\_support flag,
> > > > > colo compare will send/recv packet with vnet\_hdr\_len.
> > >
>
