* Kashyap Chamarthy (kcham...@redhat.com) wrote:
> On Wed, May 03, 2017 at 11:42:57AM +0100, Dr. David Alan Gilbert (git) wrote:
>
> A small comment inline, in the 'ifndef' section.
>
> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> >
> > Many users now prefer to use drive_mirror over NBD as an
> > alternative to the older migrate -b option; drive_mirror is
> > more complex to setup but gives you more options (e.g. only
> > migrating some of the disks if some of them are shared).
> >
> > Allow the large chunk of block migration code to be compiled
> > out for those who don't use it.
> >
> > Based on a downstream-patch we've had for a while by Jeff Cody.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > ---
> > configure | 11 +++++++++++
> > migration/Makefile.objs | 2 +-
> > migration/migration.c | 12 ++++++++++++
> > vl.c | 2 ++
> > 4 files changed, 26 insertions(+), 1 deletion(-)
> >
> > diff --git a/configure b/configure
> > index 48a9370cc6..69eed5fb8d 100755
> > --- a/configure
> > +++ b/configure
> > @@ -316,6 +316,7 @@ vte=""
> > virglrenderer=""
> > tpm="yes"
> > libssh2=""
> > +live_block_migration="yes"
> > numa=""
> > tcmalloc="no"
> > jemalloc="no"
> > @@ -1168,6 +1169,10 @@ for opt do
> > ;;
> > --enable-libssh2) libssh2="yes"
> > ;;
> > + --disable-live-block-migration) live_block_migration="no"
> > + ;;
> > + --enable-live-block-migration) live_block_migration="yes"
> > + ;;
> > --disable-numa) numa="no"
> > ;;
> > --enable-numa) numa="yes"
> > @@ -1400,6 +1405,7 @@ disabled with --disable-FEATURE, default is enabled
> > if available:
> > libnfs nfs support
> > smartcard smartcard support (libcacard)
> > libusb libusb (for usb passthrough)
> > + live-block-migration Block migration in the main migration stream
> > usb-redir usb network redirection support
> > lzo support of lzo compression library
> > snappy support of snappy compression library
> > @@ -5210,6 +5216,7 @@ echo "TPM support $tpm"
> > echo "libssh2 support $libssh2"
> > echo "TPM passthrough $tpm_passthrough"
> > echo "QOM debugging $qom_cast_debug"
> > +echo "Live block migration $live_block_migration"
> > echo "lzo support $lzo"
> > echo "snappy support $snappy"
> > echo "bzip2 support $bzip2"
> > @@ -5776,6 +5783,10 @@ if test "$libssh2" = "yes" ; then
> > echo "LIBSSH2_LIBS=$libssh2_libs" >> $config_host_mak
> > fi
> >
> > +if test "$live_block_migration" = "yes" ; then
> > + echo "CONFIG_LIVE_BLOCK_MIGRATION=y" >> $config_host_mak
> > +fi
> > +
> > # USB host support
> > if test "$libusb" = "yes"; then
> > echo "HOST_USB=libusb legacy" >> $config_host_mak
> > diff --git a/migration/Makefile.objs b/migration/Makefile.objs
> > index 480dd493a9..200b5e0c67 100644
> > --- a/migration/Makefile.objs
> > +++ b/migration/Makefile.objs
> > @@ -9,5 +9,5 @@ common-obj-y += qjson.o
> >
> > common-obj-$(CONFIG_RDMA) += rdma.o
> >
> > -common-obj-y += block.o
> > +common-obj-$(CONFIG_LIVE_BLOCK_MIGRATION) += block.o
> >
> > diff --git a/migration/migration.c b/migration/migration.c
> > index 353f2728cf..ffce72aabc 100644
> > --- a/migration/migration.c
> > +++ b/migration/migration.c
> > @@ -692,6 +692,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> >
> > populate_ram_info(info, s);
> >
> > +#ifdef CONFIG_LIVE_BLOCK_MIGRATION
> > if (blk_mig_active()) {
> > info->has_disk = true;
> > info->disk = g_malloc0(sizeof(*info->disk));
> > @@ -699,6 +700,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> > info->disk->remaining = blk_mig_bytes_remaining();
> > info->disk->total = blk_mig_bytes_total();
> > }
> > +#endif
> >
> > if (cpu_throttle_active()) {
> > info->has_cpu_throttle_percentage = true;
> > @@ -720,6 +722,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> >
> > populate_ram_info(info, s);
> >
> > +#ifdef CONFIG_LIVE_BLOCK_MIGRATION
> > if (blk_mig_active()) {
> > info->has_disk = true;
> > info->disk = g_malloc0(sizeof(*info->disk));
> > @@ -727,6 +730,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
> > info->disk->remaining = blk_mig_bytes_remaining();
> > info->disk->total = blk_mig_bytes_total();
> > }
> > +#endif
> >
> > get_xbzrle_cache_stats(info);
> > break;
> > @@ -1222,6 +1226,14 @@ void qmp_migrate(const char *uri, bool has_blk, bool
> > blk,
> > params.blk = has_blk && blk;
> > params.shared = has_inc && inc;
> >
> > +#ifndef CONFIG_LIVE_BLOCK_MIGRATION
> > + if (params.blk || params.shared) {
> > + error_setg(errp, "QEMU compiled without old-style block migration.
> > "
> > + "Use drive_mirror+NBD.");
>
> Is it worth spelling out briefly what the "old-style block migration"
> is? Something like:
>
> "QEMU compiled without old-style (i.e. QMP `migrate` with
> "inc":true) block migration. Use `drive-mirror`+NBD")
>
> But I also wonder if it's needlessly wordy, so your call to incorporate
> it or not.
I was trying to find a short way to say it, and that's the closest I got to.
> I spelled out the QMP equivalent (as opposed to HMP: 'migrate -b')
> because, that's what users of higher layers (libvirt, OpenStack etc) see
> in their QMP interactions with QEMU, when the old-style approach is
> used:
>
>
> {"execute":"migrate","arguments":{{"detach":true,"blk":false,"inc":true,"uri":"fd:migrate"}
But would openstack users even know about QMP?
Dave
>
> [...]
>
> --
> /kashyap
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
