From: Linhaifeng <haifeng.lin@huawei.com>
To: "Xie, Huawei" <huawei.xie@intel.com>,
"'Tetsuya Mukawa'" <mukawa@igel.co.jp>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] vhost-user technical isssues
Date: Thu, 13 Nov 2014 14:27:42 +0800 [thread overview]
Message-ID: <54644F5E.8080407@huawei.com> (raw)
In-Reply-To: <C37D651A908B024F974696C65296B57B0F2F19EF@SHSMSX101.ccr.corp.intel.com>
On 2014/11/12 5:37, Xie, Huawei wrote:
> Hi Tetsuya:
> There are two major technical issues in my mind for vhost-user implementation.
>
> 1) memory region map
> Vhost-user passes us file fd and offset for each memory region. Unfortunately 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 double 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 that bug.
>
the size of region 0 is not same as the file size. may be you should mmap the other region.
region 0:
gpa = 0x0
size = 655360
ua = 0x2aaaaac00000
offset = 0
region 1:// use this region to mmap.BTW how to avoid mmap twice when there are two devices?
gpa = 0xC0000
size = 2146697216
ua = 0x2aaaaacc0000
offset = 786432
> 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.
>
> Thoughts?
>
> -huawei
>
>
--
Regards,
Haifeng
next prev parent reply other threads:[~2014-11-13 6:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-11 21:37 Xie, Huawei
2014-11-12 4:12 ` Tetsuya Mukawa
2014-11-13 6:30 ` Linhaifeng
2014-11-14 2:30 ` Tetsuya Mukawa
2014-11-14 3:13 ` Linhaifeng
2014-11-14 3:40 ` Tetsuya Mukawa
2014-11-14 4:05 ` Tetsuya Mukawa
2014-11-14 4:42 ` Linhaifeng
2014-11-14 5:12 ` Tetsuya Mukawa
2014-11-14 5:30 ` Linhaifeng
2014-11-14 6:57 ` Tetsuya Mukawa
2014-11-14 10:59 ` Xie, Huawei
2014-11-17 6:14 ` Tetsuya Mukawa
2014-11-14 0:22 ` Xie, Huawei
2014-11-14 2:52 ` Tetsuya Mukawa
2014-11-15 1:42 ` Xie, Huawei
2014-11-13 6:12 ` Linhaifeng
2014-11-13 6:27 ` Linhaifeng [this message]
2014-11-14 1:28 ` Xie, Huawei
2014-11-14 2:24 ` Linhaifeng
2014-11-14 2:35 ` Tetsuya Mukawa
2014-11-14 6:24 ` Xie, Huawei
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54644F5E.8080407@huawei.com \
--to=haifeng.lin@huawei.com \
--cc=dev@dpdk.org \
--cc=huawei.xie@intel.com \
--cc=mukawa@igel.co.jp \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).