Re: [Qemu-devel] [PATCH v7 RFC] block/vxhs: Initial commit to add Veritas HyperScale VxHS block device support

[Daniel P. Berrange]

On Thu, Feb 02, 2017 at 09:22:46PM +0000, Ketan Nilangekar wrote:
> 
> On 2/2/17, 12:57 PM, "Ketan Nilangekar" <address@hidden> wrote:
>         
>     [Ketan]
>     Does the QIO interface allow for readv/writev over network for unsecure 
> sockets?
>     
> [Ketan]
> I checked the qio implementation and it seems that there is a pseudo
> implementation of readv/writev which iterates over the individual
> iovecs to make send/recv syscalls. This can’t be too good for performance.

I think you looked at the Win32 code - the qio_channel_socket_writev
and qio_channel_socket_readv methods which are built on non-Win32
platforms use recvmsg/sendmsg to handle iovecs in a single operation.

> Are you suggesting we use the qio interface for secure communication only
> and leave the unsecure communication to libqnio?

If you expect non-QEMU apps to use libqnio, then you could keep support
for plain & TLS sockets in libqnio. Just provide the I/O callbacks facility
as an alternative approach which can be used by QEMU for secure & insecure
I/O handling.

Regards,
Daniel
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