[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <61d5c470-a8bf-86d5-d1fe-b4b577a85967@linux.intel.com>
Date: Tue, 30 Aug 2016 14:53:10 +0800
From: Xiao Guangrong <guangrong.xiao@...ux.intel.com>
To: Ross Zwisler <ross.zwisler@...ux.intel.com>
Cc: Dan Williams <dan.j.williams@...el.com>,
Yumei Huang <yuhuang@...hat.com>, KVM <kvm@...r.kernel.org>,
"linux-nvdimm@...ts.01.org" <linux-nvdimm@...ts.01.org>,
"qemu-devel@...gnu.org" <qemu-devel@...gnu.org>,
LKML <linux-kernel@...r.kernel.org>,
Linux ACPI <linux-acpi@...r.kernel.org>,
Stefan Hajnoczi <stefanha@...hat.com>
Subject: Re: DAX can not work on virtual nvdimm device
On 08/30/2016 03:30 AM, Ross Zwisler wrote:
>
> Can you please verify that you are using "usable" memory for your memmap? All
> the details are here:
>
> https://nvdimm.wiki.kernel.org/how_to_choose_the_correct_memmap_kernel_parameter_for_pmem_on_your_system
Sure.
This is the BIOS E820 info in the guest:
e820: BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x00000000bffdefff] usable
BIOS-e820: [mem 0x00000000bffdf000-0x00000000bfffffff] reserved
BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
BIOS-e820: [mem 0x0000000100000000-0x000000083fffffff] usable
NX (Execute Disable) protection: active
e820: user-defined physical RAM map:
user: [mem 0x0000000000000000-0x000000000009fbff] usable
user: [mem 0x000000000009fc00-0x000000000009ffff] reserved
user: [mem 0x00000000000f0000-0x00000000000fffff] reserved
user: [mem 0x0000000000100000-0x00000000bffdefff] usable
user: [mem 0x00000000bffdf000-0x00000000bfffffff] reserved
user: [mem 0x00000000feffc000-0x00000000feffffff] reserved
user: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
user: [mem 0x0000000100000000-0x000000027fffffff] usable
user: [mem 0x0000000280000000-0x00000003ffffffff] persistent (type 12)
user: [mem 0x0000000400000000-0x000000083fffffff] usable
So that the memory we used to emulate PMEM split the 'usable' region.
>
> My guess is that Boaz was correct, and that your memmap is off using addresses
> that don't actually map to memory.
I do not think so. :(
I did mmap-write and mmap-read test, the data written by mmap-write can be
correctly read out, so that the backend memory is really existing.
Thanks!
Powered by blists - more mailing lists