6 Commits

Author SHA1 Message Date
Robert Wing
38dfb0626f bhyve/snapshot: use SOCK_DGRAM instead of SOCK_STREAM
The save/restore feature uses a unix domain socket to send messages
from bhyvectl(8) to a bhyve(8) process. A datagram socket will suffice
for this.

An added benefit of using a datagram socket is simplified code. For
bhyve, the listen/accept calls are dropped; and for bhyvectl, the
connect() call is dropped.

EPRINTLN handles raw mode for bhyve(8), use it to print error messages.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D28983
2021-03-07 15:23:29 -09:00
Robert Wing
5ce2d4a1c2 bhyve/snapshot: drop mkdir when creating the unix domain socket
Add /var/run/bhyve/ to BSD.var.dist so we don't have to call mkdir when
creating the unix domain socket for a given bhyve vm.

The path to the unix domain socket for a bhyve vm will now be
/var/run/bhyve/vmname instead of /var/run/bhyve/checkpoint/vmname

Move BHYVE_RUN_DIR from snapshot.c to snapshot.h so it can be shared
to bhyvectl(8).

Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D28783
2021-02-22 11:31:07 -09:00
Robert Wing
c4df8cbfde Remove bvmconsole and bvmdebug.
Now that bhyve(8) supports UART, bvmconsole and bvmdebug are no longer needed.

This also removes the '-b' and '-g' flag from bhyve(8). These two flags were
marked deprecated in r368519.

Reviewed by:    grehan, kevans
Approved by:    kevans (mentor)
Differential Revision:  https://reviews.freebsd.org/D27490
2020-12-23 17:15:23 -09:00
John Baldwin
1b9c78611d Suspend I/O on ahci-cd devices during a snapshot.
Submitted by:	Vitaliy Gusev <gusev.vitaliy@gmail.com>
2020-11-28 04:21:22 +00:00
John Baldwin
bb481f6718 bhyve: Add snapshot support for virtio-rnd.
This uses the same snapshot routine as other VirtIO devices.

Submitted by:	Vitaliy Gusev <gusev.vitaliy@gmail.com>
Differential Revision:	https://reviews.freebsd.org/D26265
2020-11-28 04:06:09 +00:00
John Baldwin
483d953a86 Initial support for bhyve save and restore.
Save and restore (also known as suspend and resume) permits a snapshot
to be taken of a guest's state that can later be resumed.  In the
current implementation, bhyve(8) creates a UNIX domain socket that is
used by bhyvectl(8) to send a request to save a snapshot (and
optionally exit after the snapshot has been taken).  A snapshot
currently consists of two files: the first holds a copy of guest RAM,
and the second file holds other guest state such as vCPU register
values and device model state.

To resume a guest, bhyve(8) must be started with a matching pair of
command line arguments to instantiate the same set of device models as
well as a pointer to the saved snapshot.

While the current implementation is useful for several uses cases, it
has a few limitations.  The file format for saving the guest state is
tied to the ABI of internal bhyve structures and is not
self-describing (in that it does not communicate the set of device
models present in the system).  In addition, the state saved for some
device models closely matches the internal data structures which might
prove a challenge for compatibility of snapshot files across a range
of bhyve versions.  The file format also does not currently support
versioning of individual chunks of state.  As a result, the current
file format is not a fixed binary format and future revisions to save
and restore will break binary compatiblity of snapshot files.  The
goal is to move to a more flexible format that adds versioning,
etc. and at that point to commit to providing a reasonable level of
compatibility.  As a result, the current implementation is not enabled
by default.  It can be enabled via the WITH_BHYVE_SNAPSHOT=yes option
for userland builds, and the kernel option BHYVE_SHAPSHOT.

Submitted by:	Mihai Tiganus, Flavius Anton, Darius Mihai
Submitted by:	Elena Mihailescu, Mihai Carabas, Sergiu Weisz
Relnotes:	yes
Sponsored by:	University Politehnica of Bucharest
Sponsored by:	Matthew Grooms (student scholarships)
Sponsored by:	iXsystems
Differential Revision:	https://reviews.freebsd.org/D19495
2020-05-05 00:02:04 +00:00