From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
Hi,
This is a RFC/WIP series that enables postcopy migration
with shared memory to a vhost-user process.
It's based off current-head + Alexey's bitmap series
It's tested with vhost-user-bridge and a dpdk (modified by Maxime
that will get posted separately) - both very lightly.
It's still got a few very rough edges, but it succesfully migrates
with both normal and huge pages (2M).
The major difference over v1 is that there's a set of code
that merges vhost regions together on the qemu side so that
we get a single hugepage region on the PC spanning the 640k
hole (the hole hopefully isn't accessed by the client,
but the client used to align around it anyway).
It's also got a lot of cleanups from the comments from v1
but there's still a few things that need work.
In particular, there's still the hack around qemu waiting
for the set_mem_table to come back; I also worry what would
happen if a set-mem-table was triggered during a migrate;
I suspect it would break badly.
One problem that didn't cause a problem was madvises for hugepages;
because we register userfault directly after mmap'ing the
region in the client, we have no pages mapped and hence
the madvise's/fallocate's are fortunately not compulsary.
Still, I'd like a way to do it, it would feel safer.
A copy of this code, based off the current 2.10.0-rc4
together with Alexey's bitmap code is available here:
https://github.com/dagrh/qemu/tree/vhost-wipv2
Dave
Dr. David Alan Gilbert (32):
vhu: vu_queue_started
vhub: Only process received packets on started queues
migrate: Update ram_block_discard_range for shared
qemu_ram_block_host_offset
migration/ram: ramblock_recv_bitmap_test_byte_offset
postcopy: use UFFDIO_ZEROPAGE only when available
postcopy: Add notifier chain
postcopy: Add vhost-user flag for postcopy and check it
vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message
vhub: Support sending fds back to qemu
vhub: Open userfaultfd
postcopy: Allow registering of fd handler
vhost+postcopy: Register shared ufd with postcopy
vhost+postcopy: Transmit 'listen' to client
vhost+postcopy: Register new regions with the ufd
vhost+postcopy: Send address back to qemu
vhost+postcopy: Stash RAMBlock and offset
vhost+postcopy: Send requests to source for shared pages
vhost+postcopy: Resolve client address
postcopy: wake shared
postcopy: postcopy_notify_shared_wake
vhost+postcopy: Add vhost waker
vhost+postcopy: Call wakeups
vub+postcopy: madvises
vhost+postcopy: Lock around set_mem_table
vhost: Add VHOST_USER_POSTCOPY_END message
vhost+postcopy: Wire up POSTCOPY_END notify
postcopy: Allow shared memory
vhost-user: Claim support for postcopy
vhost: Merge neighbouring hugepage regions where appropriate
vhost: Don't break merged regions on small remove/non-adds
postcopy shared docs
contrib/libvhost-user/libvhost-user.c | 226 ++++++++++++++++++++-
contrib/libvhost-user/libvhost-user.h | 22 ++-
docs/devel/migration.txt | 39 ++++
docs/interop/vhost-user.txt | 39 ++++
exec.c | 60 ++++--
hw/virtio/trace-events | 27 +++
hw/virtio/vhost-user.c | 326 +++++++++++++++++++++++++++++-
hw/virtio/vhost.c | 121 +++++++++++-
include/exec/cpu-common.h | 4 +
migration/migration.c | 3 +
migration/migration.h | 4 +
migration/postcopy-ram.c | 359 +++++++++++++++++++++++++++-------
migration/postcopy-ram.h | 69 +++++++
migration/ram.c | 5 +
migration/ram.h | 1 +
migration/savevm.c | 13 ++
migration/trace-events | 6 +
tests/vhost-user-bridge.c | 1 +
trace-events | 3 +
vl.c | 2 +
20 files changed, 1241 insertions(+), 89 deletions(-)
--
2.13.5
