Re: [Qemu-devel] Guest application reading from pl011 without device driver

[Jiahuan Zhang]

On 22 March 2017 at 09:40, Paolo Bonzini <address@hidden> wrote:

>
> > > I am using a windows named pipe to get the data from a window
> > > host program, which uses ReadFile () in char_win.c
> >
> > OK, bugs in the windows-specific char backend would be
> > unsurprising.
> >
> > I'm not entirely sure how the chardev layer works, but
> > at the pl011 end if we return 0 from our can_receive
> > function then the chardev layer should decide it has
> > nothing to do until the pl011 later calls
> > qemu_chr_fe_accept_input(), I think.
> >
> > I've cc'd Paolo and Marc-André Lureau as the chardev
> > maintainers.
>
> Windows named pipes do not support the equivalent of "select",
> so it's possible that they cause a busy wait.  Try using a
> TCP socket instead and see if the bug goes away.
>

Hi, I am trying to use a Windows socket for serial redirection instead of
Windows named pipe.
What do you mean "the equivalent of 'select'"?


>
> Paolo
>