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

[Ketan Nilangekar]

On 2/3/17, 1:45 AM, "Daniel P. Berrange" <address@hidden> wrote:

    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.

[Ketan]
Ok I see that.
    
    > 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.

[Ketan]
We do expect non-qemu applications to use libqnio. 
However, if this is a "nice to have" from QEMU perspective, I'd like to take 
this up later.


Regards,
    Daniel
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