[Qemu-devel] [PATCH 0/7 V8] nvdimm: guarantee persistence of QEMU writes to persistent memory

junyan.he@gmx.com posted 7 patches 11 weeks ago
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Test docker-quick@centos7 passed
backends/hostmem-file.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
configure               | 29 +++++++++++++++++++++++++++++
docs/nvdimm.txt         | 23 +++++++++++++++++++++++
exec.c                  | 39 ++++++++++++++-------------------------
hw/mem/nvdimm.c         |  9 ++++++++-
include/exec/memory.h   | 31 +++++++++++++++++++++++++++++--
include/exec/ram_addr.h | 28 ++++++++++++++++++++++++++--
include/qemu/pmem.h     | 24 ++++++++++++++++++++++++
memory.c                |  8 +++++---
migration/ram.c         | 17 +++++++++++++++++
numa.c                  |  2 +-
qemu-options.hx         |  7 +++++++
stubs/Makefile.objs     |  1 +
tubs/pmem.c            | 23 +++++++++++++++++++++++
14 files changed, 249 insertions(+), 35 deletions(-)
create mode 100644 include/qemu/pmem.h
create mode 100644 stubs/pmem.c

[Qemu-devel] [PATCH 0/7 V8] nvdimm: guarantee persistence of QEMU writes to persistent memory

Posted by junyan.he@gmx.com 11 weeks ago
From: Junyan He <junyan.he@intel.com>


QEMU writes to vNVDIMM backends in the vNVDIMM label emulation and
live migration. If the backend is on the persistent memory, QEMU needs
to take proper operations to ensure its writes persistent on the
persistent memory. Otherwise, a host power failure may result in the
loss the guest data on the persistent memory.

This v3 patch series is based on Marcel's patch "mem: add share
parameter to memory-backend-ram" [1] because of the changes in patch 1.

[1] https://lists.gnu.org/archive/html/qemu-devel/2018-02/msg03858.html

Previous versions can be found at:
v7: https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg02997.html
v6: https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg00061.html
v5: https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg02258.html
V4: https://lists.gnu.org/archive/html/qemu-devel/2018-02/msg06993.html
v3: https://lists.gnu.org/archive/html/qemu-devel/2018-02/msg04365.html
v2: https://lists.gnu.org/archive/html/qemu-devel/2018-02/msg01579.html
v1: https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg05040.html

Changs in v8:
* (Patch 3) Report a error when user set 'pmem' to file-backend, while
  the qemu is lack of libpmem support. In this case, we can not ensure
  the persistence of the file-backend, so we choose to fail the build
  rather than contine and make the thing more confused.

Changes in v7:
The v6 patch set has already reviewed by Stefan Hajnoczi <stefanha@redhat.com>
No logic change in this v7 version, just:
* Spelling check and some document words refined.
* Rebase to "ram is migratable" patch set.

Changes in v6:
* (Patch 1) Expose all ram block flags rather than redefine the flags.
* (Patch 4) Use pkg-config rather the hard check when configure. 
* (Patch 7) Sync and flush all the pmem data when migration completes,
  rather than sync pages one by one in previous version.

Changes in v5:
* (Patch 9) Add post copy check and output some messages for nvdimm.

Changes in v4:
* (Patch 2) Fix compilation errors found by patchew.

Changes in v3:
* (Patch 5) Add a is_pmem flag to ram_handle_compressed() and handle
  PMEM writes in it, so we don't need the _common function.
* (Patch 6) Expose qemu_get_buffer_common so we can remove the
  unnecessary qemu_get_buffer_to_pmem wrapper.
* (Patch 8) Add a is_pmem flag to xbzrle_decode_buffer() and handle
  PMEM writes in it, so we can remove the unnecessary
  xbzrle_decode_buffer_{common, to_pmem}.
* Move libpmem stubs to stubs/pmem.c and fix the compilation failures
  of test-{xbzrle,vmstate}.c.

Changes in v2:
* (Patch 1) Use a flags parameter in file ram allocation functions.
* (Patch 2) Add a new option 'pmem' to hostmem-file.
* (Patch 3) Use libpmem to operate on the persistent memory, rather
  than re-implementing those operations in QEMU.
* (Patch 5-8) Consider the write persistence in the migration path.

Junyan:
[1/7] memory, exec: Expose all memory block related flags.
[6/7] migration/ram: Add check and info message to nvdimm post copy.
[7/7] migration/ram: ensure write persistence on loading all date to PMEM.

Haozhong:
[5/7] mem/nvdimm: ensure write persistence to PMEM in label emulation

Haozhong & Junyan:
[2/7] memory, exec: switch file ram allocation functions to 'flags' parameters
[3/7] hostmem-file: add the 'pmem' option
[4/7] configure: add libpmem support


Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Junyan He <junyan.he@intel.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>


backends/hostmem-file.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
configure               | 29 +++++++++++++++++++++++++++++
docs/nvdimm.txt         | 23 +++++++++++++++++++++++
exec.c                  | 39 ++++++++++++++-------------------------
hw/mem/nvdimm.c         |  9 ++++++++-
include/exec/memory.h   | 31 +++++++++++++++++++++++++++++--
include/exec/ram_addr.h | 28 ++++++++++++++++++++++++++--
include/qemu/pmem.h     | 24 ++++++++++++++++++++++++
memory.c                |  8 +++++---
migration/ram.c         | 17 +++++++++++++++++
numa.c                  |  2 +-
qemu-options.hx         |  7 +++++++
stubs/Makefile.objs     |  1 +
tubs/pmem.c            | 23 +++++++++++++++++++++++
14 files changed, 249 insertions(+), 35 deletions(-)
create mode 100644 include/qemu/pmem.h
create mode 100644 stubs/pmem.c

-- 
2.7.4