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[Qemu-devel] [PATCH v6 00/47] Postcopy implementation
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[Qemu-devel] [PATCH v6 00/47] Postcopy implementation |
Date: |
Tue, 14 Apr 2015 18:03:26 +0100 |
From: "Dr. David Alan Gilbert" <address@hidden>
This is the 6th cut of my version of postcopy; it is designed for use with
the Linux kernel additions posted by Andrea Arcangeli here:
git clone --reference linux -b userfault18
git://git.kernel.org/pub/scm/linux/kernel/git/andrea/aa.git
(Note this is a different API from the last version)
This qemu series can be found at:
https://github.com/orbitfp7/qemu.git
on the wp3-postcopy-v6 tag.
It addresses some but not yet all of the previous review comments;
however there are a couple of large simplifications, so it seems
worth posting to meet the new kernel API and to stop people
reviewing deadcode.
Note: That the userfaultfd.h header is no longer included in this
tree:
- if you're building with the appropriate kernel headers it should find it
- if you're building on a host that doesn't have the kernel headers
installed in the right place then:
configure with: --extra-cflags="-D__NR_userfaultfd=323"
cp include/uapi/linux/userfaultfd.h into somewhere in the include
path, e.g. /usr/local/include/linux
v6
Removed the PMI bitmaps
- Andrea updated the kernel API so that userspace doesn't
need to do wakeups, and thus QEMU doesn't need to keep
track of which pages it's received; there is a price - which
is we end up sending more dupes to the source, but it simplifies
stuff a lot and makes the normal paths a lot quicker.
(10s of line change in kernel, 10%-ish simplification in this code!)
Changed discard message format to a simpler start/end address scheme
and rework discard and chunking code to work in long's to match bitmap
'qemu_get_buffer_less_copy' for postcopy pages
- avoids a userspace copy since the kernel now does it
- the new qemufile interface might also be useful for other places that
don't need a copy (maybe xbzrle?)
Changed the blockingness of the incoming fd
it was incorrectly blocking during the precopy phase after a postcopy was
enabled, causing the HMP to be unavailable. It's now blocking only once
the postcopy thread starts up, since it's not a coroutine it can't deal
with the yields in qemu_file.
An error on the return-path now marks the migration as failed
Fixups from Dave Gibson's comments
Removed can_postcopy, renamed save_complete to save_complete_precopy
added save_complete_postcopy
Simplified loadvm loop exits
discard message format changes above
and many more smaller changes.
small fixups for RCU
This work has been partially funded by the EU Orbit project:
see http://www.orbitproject.eu/about/
TODO:
The major work is to rework the page send/receive loops so that supporting
larger host pages doesn't make it quite as messy.
Dr. David Alan Gilbert (47):
Start documenting how postcopy works.
Split header writing out of qemu_savevm_state_begin
qemu_ram_foreach_block: pass up error value, and down the ramblock
name
Add qemu_get_counted_string to read a string prefixed by a count byte
Create MigrationIncomingState
Provide runtime Target page information
Move copy out of qemu_peek_buffer
Add qemu_get_buffer_less_copy to avoid copies some of the time
Add wrapper for setting blocking status on a QEMUFile
Rename save_live_complete to save_live_complete_precopy
Return path: Open a return path on QEMUFile for sockets
Return path: socket_writev_buffer: Block even on non-blocking fd's
Migration commands
Return path: Control commands
Return path: Send responses from destination to source
Return path: Source handling of return path
ram_debug_dump_bitmap: Dump a migration bitmap as text
Move loadvm_handlers into MigrationIncomingState
Rework loadvm path for subloops
Add migration-capability boolean for postcopy-ram.
Add wrappers and handlers for sending/receiving the postcopy-ram
migration messages.
MIG_CMD_PACKAGED: Send a packaged chunk of migration stream
migrate_init: Call from savevm
Modify save_live_pending for postcopy
postcopy: OS support test
migrate_start_postcopy: Command to trigger transition to postcopy
MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state
Add qemu_savevm_state_complete_postcopy
Postcopy: Maintain sentmap and calculate discard
postcopy: Incoming initialisation
postcopy: ram_enable_notify to switch on userfault
Postcopy: Postcopy startup in migration thread
Postcopy end in migration_thread
Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
Page request: Process incoming page request
Page request: Consume pages off the post-copy queue
postcopy_ram.c: place_page and helpers
Postcopy: Use helpers to map pages during migration
qemu_ram_block_from_host
Don't sync dirty bitmaps in postcopy
Host page!=target page: Cleanup bitmaps
Postcopy; Handle userfault requests
Start up a postcopy/listener thread ready for incoming page data
postcopy: Wire up loadvm_postcopy_handle_ commands
End of migration for postcopy
Disable mlock around incoming postcopy
Inhibit ballooning during postcopy
arch_init.c | 868 ++++++++++++++++++++++++++++++++++++---
balloon.c | 11 +
docs/migration.txt | 167 ++++++++
exec.c | 74 +++-
hmp-commands.hx | 15 +
hmp.c | 7 +
hmp.h | 1 +
hw/ppc/spapr.c | 2 +-
hw/virtio/virtio-balloon.c | 4 +-
include/exec/cpu-all.h | 2 -
include/exec/cpu-common.h | 7 +-
include/migration/migration.h | 126 +++++-
include/migration/postcopy-ram.h | 88 ++++
include/migration/qemu-file.h | 15 +-
include/migration/vmstate.h | 10 +-
include/qemu/typedefs.h | 5 +
include/sysemu/balloon.h | 2 +
include/sysemu/sysemu.h | 45 +-
migration/Makefile.objs | 2 +-
migration/block.c | 9 +-
migration/migration.c | 743 +++++++++++++++++++++++++++++++--
migration/postcopy-ram.c | 715 ++++++++++++++++++++++++++++++++
migration/qemu-file-unix.c | 106 ++++-
migration/qemu-file.c | 100 ++++-
migration/rdma.c | 4 +-
migration/vmstate.c | 5 +-
qapi-schema.json | 19 +-
qmp-commands.hx | 19 +
savevm.c | 809 ++++++++++++++++++++++++++++++++----
trace-events | 77 +++-
30 files changed, 3832 insertions(+), 225 deletions(-)
create mode 100644 include/migration/postcopy-ram.h
create mode 100644 migration/postcopy-ram.c
--
2.1.0
- [Qemu-devel] [PATCH v6 00/47] Postcopy implementation,
Dr. David Alan Gilbert (git) <=
- [Qemu-devel] [PATCH v6 02/47] Split header writing out of qemu_savevm_state_begin, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 01/47] Start documenting how postcopy works., Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 04/47] Add qemu_get_counted_string to read a string prefixed by a count byte, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 03/47] qemu_ram_foreach_block: pass up error value, and down the ramblock name, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 05/47] Create MigrationIncomingState, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 06/47] Provide runtime Target page information, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 09/47] Add wrapper for setting blocking status on a QEMUFile, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 07/47] Move copy out of qemu_peek_buffer, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 13/47] Migration commands, Dr. David Alan Gilbert (git), 2015/04/14
- [Qemu-devel] [PATCH v6 10/47] Rename save_live_complete to save_live_complete_precopy, Dr. David Alan Gilbert (git), 2015/04/14