diff options
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/migration.json | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/qapi/migration.json b/qapi/migration.json index a605dc26db..43babd1df4 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -158,8 +158,11 @@ # # @pre-switchover: Paused before device serialisation. (since 2.11) # -# @device: During device serialisation when pause-before-switchover is -# enabled (since 2.11) +# @device: During device serialisation (also known as switchover phase). +# Before 9.2, this is only used when (1) in precopy, and (2) when +# pre-switchover capability is enabled. After 10.0, this state will +# always be present for every migration procedure as the switchover +# phase. (since 2.11) # # @wait-unplug: wait for device unplug request by guest OS to be # completed. (since 4.2) @@ -614,9 +617,48 @@ # or COLO. # # (since 8.2) +# +# @cpr-transfer: This mode allows the user to transfer a guest to a +# new QEMU instance on the same host with minimal guest pause +# time by preserving guest RAM in place. Devices and their pinned +# pages will also be preserved in a future QEMU release. +# +# The user starts new QEMU on the same host as old QEMU, with +# command-line arguments to create the same machine, plus the +# -incoming option for the main migration channel, like normal +# live migration. In addition, the user adds a second -incoming +# option with channel type "cpr". This CPR channel must support +# file descriptor transfer with SCM_RIGHTS, i.e. it must be a +# UNIX domain socket. +# +# To initiate CPR, the user issues a migrate command to old QEMU, +# adding a second migration channel of type "cpr" in the channels +# argument. Old QEMU stops the VM, saves state to the migration +# channels, and enters the postmigrate state. Execution resumes +# in new QEMU. +# +# New QEMU reads the CPR channel before opening a monitor, hence +# the CPR channel cannot be specified in the list of channels for +# a migrate-incoming command. It may only be specified on the +# command line. +# +# The main channel address cannot be a file type, and for an +# inet socket, the port cannot be 0 (meaning dynamically choose +# a port). +# +# Memory-backend objects must have the share=on attribute, but +# memory-backend-epc is not supported. The VM must be started +# with the '-machine aux-ram-share=on' option. +# +# When using -incoming defer, you must issue the migrate command +# to old QEMU before issuing any monitor commands to new QEMU. +# However, new QEMU does not open and read the migration stream +# until you issue the migrate incoming command. +# +# (since 10.0) ## { 'enum': 'MigMode', - 'data': [ 'normal', 'cpr-reboot' ] } + 'data': [ 'normal', 'cpr-reboot', 'cpr-transfer' ] } ## # @ZeroPageDetection: @@ -1578,11 +1620,12 @@ # The migration channel-type request options. # # @main: Main outbound migration channel. +# @cpr: Checkpoint and restart state channel. # # Since: 8.1 ## { 'enum': 'MigrationChannelType', - 'data': [ 'main' ] } + 'data': [ 'main', 'cpr' ] } ## # @MigrationChannel: |