Re: [Qemu-devel] DAX can not work on virtual nvdimm device

[Xiao Guangrong]

On 08/31/2016 01:09 AM, Dan Williams wrote:

> Can you post your exact reproduction steps?  This test is not failing for me.

Sure.

1. make the guest kernel based on your tree, the top commit is
   10d7902fa0e82b (dax: unmap/truncate on device shutdown) and
   the config file can be found in this thread.

2. add guest kernel command line: memmap=6G!10G

3: start the guest:
   x86_64-softmmu/qemu-system-x86_64 -machine pc,nvdimm --enable-kvm \
   -smp 16 -m 32G,maxmem=100G,slots=100 /other/VMs/centos6.img -monitor stdio

4: in guest:
   mkfs.ext4 /dev/pmem0
   mount -o dax /dev/pmem0  /mnt/pmem/
   echo > /mnt/pmem/xxx
   ./mmap /mnt/pmem/xxx
   ./read /mnt/pmem/xxx

  The source code of mmap and read has been attached in this mail.

  Hopefully, you can detect the error triggered by read test.

Thanks!

read.c
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mmap.c
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