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From: "Xie, Huawei" <huawei.xie@intel.com>
To: 'Tetsuya Mukawa' <mukawa@igel.co.jp>, "dev@dpdk.org" <dev@dpdk.org>
Thread-Topic: vhost-user technical isssues
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Date: Tue, 11 Nov 2014 21:37:47 +0000
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Subject: [dpdk-dev] vhost-user technical isssues
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Hi Tetsuya:
There are two major technical issues in my mind for vhost-user implementati=
on.

1) memory region map
Vhost-user passes us file fd and offset for each memory region. Unfortunate=
ly the mmap offset is "very" wrong. I discovered this issue long time ago, =
and also found
that I couldn't mmap the huge page file even with correct offset(need doubl=
e check).
Just now I find that people reported this issue on Nov 3.
[Qemu-devel] [PULL 27/29] vhost-user: fix mmap offset calculation
Anyway, I turned to the same idea used in our DPDK vhost-cuse: only use the=
 fd for region(0) to map the  whole file.
I think we should use this way temporarily to support qemu-2.1 as it has th=
at bug.

2) what message is the indicator for vhost start/release?
Previously  for vhost-cuse, it has SET_BACKEND message.
What we should do for vhost-user?
SET_VRING_KICK for start?
What about for release?
Unlike the kernel virtio, the DPDK virtio in guest could be restarted.=20

Thoughts?

-huawei