Re: [Qemu-devel] Windows Pipe

[Jiahuan Zhang]

I think the reading failure in 2 is because there is no writing to the pipe
from the frontend (serial port).

So i wonder if the windows pipe implementation is complete. I mean dual-way
pipe.

>From the codes, I sense not. If somebody knows please inform me. 🙏 Thanks
a lot!

On 1 March 2017 at 16:12, Jiahuan Zhang <address@hidden> wrote:

> What I have done is two things.
>
> 1. I create a NamedPipeClient.exe to open the pipe and write a string into
> it. QEMU indicates the string is recieved from the pipe.
>
> 2. I create another NamedPipeClient.exe to open the pipe and read the data
> in the pipe. In qemu, I run a test.bin as kernel with versatilepb.
>  test.bin assigns a string to UART0, which is redirected to the pipe.
> (test.bin has been verified by -serial stdio.) The test result is: pipe is
> opened by NamedPipeClient.exe, but nothing on the pipe to read.
>
> the NamedPipeClient.exe is created by visual studio.
>
> On 1 March 2017 at 15:58, Marc-André Lureau <address@hidden>
> wrote:
>
>> Hi
>>
>> On Wed, Mar 1, 2017 at 6:42 PM Jiahuan Zhang <address@hidden>
>> wrote:
>>
>>> Hi,
>>>
>>> I agree with you about win_chr_poll(). But what I wonder is how to write
>>> data into the pipe for the host to get. I see "writeFile()" in
>>> "win_chr_write()", but have no idea how to use it. Or I have to write
>>> something for this writing. In this case, I don't know what the right
>>> buffer pointer for WriteFile() is.
>>>
>>> Any clue is greatly appreciated!
>>>
>>>
>> According to the documentation, it "creates a single duplex pipe at
>> \\.pipe\path", you'll have to open and write to it from a different
>> application. I don't know if there are console applications that can open
>> pipe you can use, you'll have to do some research or write one!
>>
>>
>> On 1 March 2017 at 15:25, Marc-André Lureau <address@hidden>
>>> wrote:
>>>
>>> Hi
>>>
>>> On Wed, Mar 1, 2017 at 5:16 PM Jiahuan Zhang <address@hidden>
>>> wrote:
>>>
>>> Dear QEMU developers,
>>>
>>> I want the host-guest communication for QEMU. I want to achieve
>>> it via serial port redirection to a pipe. My host is windows and guest is
>>> Linux. QEMU is in version 2.8.50
>>>
>>> I looked into char-pipe.c and char-win.c, and find that the current QEMU
>>> only supports reading data on the pipe from host to guest for Windows.
>>> See *win_chr_pipe_init
>>> () *in char-pipe.c
>>>
>>> Is it true?
>>>
>>>
>>> Not exactly, for some reason, the win-chr-pipe uses a poll,
>>> win_chr_poll() that read from the pipe and write to the frontend (the vm
>>> serial).  I haven't tested the windows pipe implementation, only the
>>> console one, but it looks like it should work. Hopefully someone using qemu
>>> on windows can help you.
>>>
>>>
>>> I don't know how to use *win_chr_write() *in char-win.c.
>>> Can you please present an example?
>>>
>>> best regards,
>>> Jiahuan
>>>
>>> --
>>> Marc-André Lureau
>>>
>>>
>>> --
>> Marc-André Lureau
>>
>
>