From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37341) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fSjVZ-0008Fv-Hp for qemu-devel@nongnu.org; Tue, 12 Jun 2018 09:38:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fSjVV-0004qO-FD for qemu-devel@nongnu.org; Tue, 12 Jun 2018 09:38:49 -0400 Received: from mout.gmx.net ([212.227.15.18]:34529) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fSjVV-0004p5-1U for qemu-devel@nongnu.org; Tue, 12 Jun 2018 09:38:45 -0400 From: Junyan He Sender: Junyan He Date: Tue, 12 Jun 2018 13:38:08 +0000 Message-ID: References: <1527840629-18648-1-git-send-email-junyan.he@gmx.com>, <20180612140643.6f6ed34d@redhat.com> In-Reply-To: <20180612140643.6f6ed34d@redhat.com> Content-Language: en-US MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH V6 0/7] nvdimm: guarantee persistence of QEMU writes to persistent memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: Haozhong Zhang , "xiaoguangrong.eric@gmail.com" , "crosthwaite.peter@gmail.com" , "mst@redhat.com" , "qemu-devel@nongnu.org" , "dgilbert@redhat.com" , "quintela@redhat.com" , Junyan He , "stefanha@redhat.com" , "pbonzini@redhat.com" , "rth@twiddle.net" , "ehabkost@redhat.com" He have pmem_persist and pmem_memcpy_persist stub functions. If no libpmem and user really specify pmem=3Don, we just do nothing or just= memcpy. Real persistent memory always require libpmem support its load/save. If pmem=3Don and without libpmem, we can think that user want to imitate pmem=3Don while the HW environment is without real persistent memory existi= ng. It may help debug on some machine without real pmem. ________________________________ From: Qemu-devel on beh= alf of Igor Mammedov Sent: Tuesday, June 12, 2018 12:06:43 PM To: junyan.he@gmx.com Cc: Haozhong Zhang; xiaoguangrong.eric@gmail.com; crosthwaite.peter@gmail.c= om; mst@redhat.com; qemu-devel@nongnu.org; dgilbert@redhat.com; quintela@re= dhat.com; Junyan He; stefanha@redhat.com; pbonzini@redhat.com; rth@twiddle.= net; ehabkost@redhat.com Subject: Re: [Qemu-devel] [PATCH V6 0/7] nvdimm: guarantee persistence of Q= EMU writes to persistent memory On Fri, 1 Jun 2018 16:10:22 +0800 junyan.he@gmx.com wrote: > From: Junyan He > > 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. extra question, what are expected behavior when QEMU is built without libpmem and user specifies pmem=3Don for backend? > > 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 > 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 > > 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' param= eters > [3/7] hostmem-file: add the 'pmem' option > [4/7] configure: add libpmem support > > > Signed-off-by: Haozhong Zhang > Signed-off-by: Junyan He > > --- > backends/hostmem-file.c | 28 +++++++++++++++++++++++++++- > configure | 29 +++++++++++++++++++++++++++++ > docs/nvdimm.txt | 14 ++++++++++++++ > exec.c | 36 ++++++++++++++---------------------- > 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 | 18 ++++++++++++++++++ > numa.c | 2 +- > qemu-options.hx | 7 +++++++ > stubs/Makefile.objs | 1 + > stubs/pmem.c | 23 +++++++++++++++++++++++ > 14 files changed, 226 insertions(+), 32 deletions(-)