ping?
On 01/17/18 16:13 +0800, Haozhong Zhang wrote:
> v3 is based on Eduardo's machine-next tree. Changes of
> memory-backend-file are based on my previous patches in that tree.
>
>
> Linux 4.15 introduces a new mmap flag MAP_SYNC, which can be used to
> guarantee the write persistence to mmap'ed files supporting DAX (e.g.,
> files on ext4/xfs file system mounted with '-o dax').
>
> A description of MAP_SYNC and MAP_SHARED_VALIDATE can be found at
> https://patchwork.kernel.org/patch/10028151/
>
> This patchset enables QEMU to use MAP_SYNC flag for memory-backend-file,
> in order to guarantee the guest write persistence to backend files
> supporting DAX.
>
> A new auto on/off option 'sync' is added to memory-backend-file:
> - on: try to pass MAP_SYNC to mmap(2); if MAP_SYNC is not supported or
> 'share=off', QEMU will abort
> - off: never pass MAP_SYNC to mmap(2)
> - auto (default): if MAP_SYNC is supported and 'share=on', work as if
> 'sync=on'; otherwise, work as if 'sync=off'
>
> Changes in v3:
> * Patch 1: add MAP_SHARED_VALIDATE in both sync=on and sync=auto
> cases, and add back the retry mechanism. MAP_SYNC will be ignored
> by Linux kernel 4.15 if MAP_SHARED_VALIDATE is missed.
> * Patch 1: define MAP_SYNC and MAP_SHARED_VALIDATE as 0 on non-Linux
> platforms in order to make qemu_ram_mmap() compile on those platforms.
> * Patch 2&3: include more information in error messages of
> memory-backend in hope to help user to identify the error.
> (Dr. David Alan Gilbert)
> * Patch 3: fix typo in the commit message. (Dr. David Alan Gilbert)
>
> Changes in v2:
> * Add 'sync' option to control the use of MAP_SYNC. (Eduardo Habkost)
> * Remove the unnecessary set of MAP_SHARED_VALIDATE in some cases and
> the retry mechanism in qemu_ram_mmap(). (Michael S. Tsirkin)
> * Move OS dependent definitions of MAP_SYNC and MAP_SHARED_VALIDATE
> to osdep.h. (Michael S. Tsirkin)
>
> Haozhong Zhang (3):
> util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap()
> hostmem: add hostmem type name and id in error messages
> hostmem-file: add 'sync' option
>
> backends/hostmem-file.c | 49
> +++++++++++++++++++++++++++++++++++++++++++----
> backends/hostmem.c | 11 +++++++----
> docs/nvdimm.txt | 15 ++++++++++++++-
> exec.c | 13 ++++++++-----
> include/exec/memory.h | 4 ++++
> include/exec/ram_addr.h | 6 +++---
> include/qemu/mmap-alloc.h | 3 ++-
> include/qemu/osdep.h | 18 +++++++++++++++++
> memory.c | 6 ++++--
> numa.c | 2 +-
> qemu-options.hx | 21 +++++++++++++++++++-
> util/mmap-alloc.c | 24 +++++++++++++++++++++--
> util/oslib-posix.c | 2 +-
> 13 files changed, 149 insertions(+), 25 deletions(-)
>
> --
> 2.14.1
>
