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
this on the branch.
Original commit message:
Initial bhyve native graphics support.
This adds emulations for a raw framebuffer device, PS2 keyboard/mouse,
XHCI USB controller and a USB tablet.
A simple VNC server is provided for keyboard/mouse input, and graphics
output.
A VGA emulation is included, but is currently disconnected until an
additional bhyve change to block out VGA memory is committed.
Credits:
- raw framebuffer, VNC server, XHCI controller, USB bus/device emulation
and UEFI f/w support by Leon Dang
- VGA, console/g, initial VNC server by tychon@
- PS2 keyboard/mouse jointly done by tychon@ and Leon Dang
- hypervisor framebuffer mem support by neel@
Tested by: Michael Dexter, in a number of revisions of this code.
With the appropriate UEFI image, FreeBSD, Windows and Linux guests can
installed and run in graphics mode using the UEFI/GOP framebuffer.
Approved by: re (gjb)
