VSS stands for "Volume Shadow Copy Service". Unlike virtual machine
snapshot, it only takes snapshot for the virtual disks, so both
filesystem and applications have to aware of it, and cooperate the
whole VSS process.
This driver exposes two device files to the userland:
/dev/hv_fsvss_dev
Normally userland programs should _not_ mess with this device file.
It is currently used by the hv_vss_daemon(8), which freezes and
thaws the filesystem. NOTE: currently only UFS is supported, if
the system mounts _any_ other filesystems, the hv_vss_daemon(8)
will veto the VSS process.
If hv_vss_daemon(8) was disabled, then this device file must be
opened, and proper ioctls must be issued to keep the VSS working.
/dev/hv_appvss_dev
Userland application can opened this device file to receive the
VSS freeze notification, hold the VSS for a while (mainly to flush
application data to filesystem), release the VSS process, and
receive the VSS thaw notification i.e. applications can run again.
The VSS will still work, even if this device file is not opened.
However, only filesystem consistency is promised, if this device
file is not opened or is not operated properly.
hv_vss_daemon(8) is started by devd(8) by default. It can be disabled
by editting /etc/devd/hyperv.conf.
Submitted by: Hongjiang Zhang <honzhan microsoft com>
Reviewed by: kib, mckusick
MFC after: 3 weeks
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8224
While I'm here, move message status codes to hv_utilreg.h, since they
will be used by the upcoming VSS stuffs.
Submitted by: Hongjiang Zhang <honzhan microsoft com>
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8391
And put them under HN_IFSTART_SUPPORT, which is by default on until
we whack the if_start related bits from base system.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8392
- Move the SYSINIT to DRIVER/SECOND, i.e. after the vm_guest becomes
determistic.
- Minor style changes.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8370
Mainly because the host side only set TCPCS and IPCS even for
UDP datagrams.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8369
And use large default temporary channel packer buffer; we really
don't want it to be expanded at run time.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8367
This paves way for more chimney sending buffer reorganization.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8343
And use it for vmbus channel logging, which can log the channel
owner's name properly, instead of vmbus0.
Submitted by: QianYue You <t-youqi microsoft com>
MFC after: 1 week
Sponsored by: Microsoft
Link status check is much more lightweight than network change detection.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8311
This will not happen in real world, since TX consumption of the vmbus
TX bufring is limitted. Better safe than sorry.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8309
All RNDIS control messages have used SG list for a while. This makes
the send context suitable for further refactoring.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8308
Currently the network change is simulated by link status changes.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8295
Submitted by: Hongjiang Zhang <honzhan microsoft com>
Reported by: Lili Deng <v-lide microsoft com>
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8238
