From: Stefan Hajnoczi <stefanha@gmail.com>
To: Jingqi Liu <jingqi.liu@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Dan Williams <dan.j.williams@intel.com>,
Xiao Guangrong <xiaoguangrong.eric@gmail.com>,
qemu-devel@nongnu.org
Subject: Re: [PATCH] docs/nvdimm: add 'pmem=on' for the device dax backend file
Date: Wed, 29 Jul 2020 11:42:41 +0100 [thread overview]
Message-ID: <20200729104241.GE37763@stefanha-x1.localdomain> (raw)
In-Reply-To: <20200715025429.28657-1-jingqi.liu@intel.com>
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On Wed, Jul 15, 2020 at 10:54:29AM +0800, Jingqi Liu wrote:
> At the end of live migration, QEMU uses msync() to flush the data to
> the backend storage. When the backend file is a character device dax,
> the pages explicitly avoid the page cache. It will return failure from msync().
> The following warning is output.
>
> "warning: qemu_ram_msync: failed to sync memory range“
>
> So we add 'pmem=on' to avoid calling msync(), use the QEMU command line:
>
> -object memory-backend-file,id=mem1,pmem=on,mem-path=/dev/dax0.0,size=4G
>
> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com>
> ---
> docs/nvdimm.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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next prev parent reply other threads:[~2020-07-29 10:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 2:54 [PATCH] docs/nvdimm: add 'pmem=on' for the device dax backend file Jingqi Liu
2020-07-24 7:15 ` Liu, Jingqi
2020-07-28 1:09 ` Liu, Jingqi
2020-07-29 10:42 ` Stefan Hajnoczi [this message]
2020-07-30 1:02 Jingqi Liu
2020-07-30 5:07 ` Pankaj Gupta
2020-08-03 0:35 Jingqi Liu
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