Re: [Qemu-devel] [Xen-devel] [PATCH v2 4/4] 9pfs: introduce init_out/in_iov_from_pdu

[Greg Kurz]

On Fri, 2 Dec 2016 11:02:44 -0800 (PST)
Stefano Stabellini <address@hidden> wrote:

> On Fri, 2 Dec 2016, Greg Kurz wrote:
> > On Mon, 28 Nov 2016 13:27:24 -0800
> > Stefano Stabellini <address@hidden> wrote:
> >   
> > > Not all 9pfs transports share memory between request and response. For
> > > those who don't, it is necessary to know how much memory is required in
> > > the response.
> > > 
> > > Split the existing init_iov_from_pdu function in two:
> > > init_out_iov_from_pdu (for writes) and init_in_iov_from_pdu (for reads).
> > > init_in_iov_from_pdu takes an additional size parameter to specify the
> > > memory required for the response message.
> > > 
> > > Signed-off-by: Stefano Stabellini <address@hidden>
> > > ---  
> > 
> > Reviewed-by: Greg Kurz <address@hidden>  
> 
> Thanks Greg! I assume you are going to apply them to your tree, right?
> 

Done.

https://github.com/gkurz/qemu/commits/9p-next

Cheers.

--
Greg

> Thanks again,
> 
> Stefano
> 
> 
> > >  hw/9pfs/9p.c               |  6 +++++-
> > >  hw/9pfs/9p.h               |  6 ++++--
> > >  hw/9pfs/virtio-9p-device.c | 28 ++++++++++++++++++----------
> > >  3 files changed, 27 insertions(+), 13 deletions(-)
> > > 
> > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> > > index 79d7201..ce1f9d9 100644
> > > --- a/hw/9pfs/9p.c
> > > +++ b/hw/9pfs/9p.c
> > > @@ -1652,7 +1652,11 @@ static void v9fs_init_qiov_from_pdu(QEMUIOVector 
> > > *qiov, V9fsPDU *pdu,
> > >      struct iovec *iov;
> > >      unsigned int niov;
> > >  
> > > -    pdu->s->transport->init_iov_from_pdu(pdu, &iov, &niov, is_write);
> > > +    if (is_write) {
> > > +        pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov);
> > > +    } else {
> > > +        pdu->s->transport->init_in_iov_from_pdu(pdu, &iov, &niov, size);
> > > +    }
> > >  
> > >      qemu_iovec_init_external(&elem, iov, niov);
> > >      qemu_iovec_init(qiov, niov);
> > > diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
> > > index c8c9aa8..4c4feaf 100644
> > > --- a/hw/9pfs/9p.h
> > > +++ b/hw/9pfs/9p.h
> > > @@ -349,8 +349,10 @@ struct V9fsTransport {
> > >                                  va_list ap);
> > >      ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const 
> > > char *fmt,
> > >                                    va_list ap);
> > > -    void        (*init_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
> > > -                                     unsigned int *pniov, bool is_write);
> > > +    void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec 
> > > **piov,
> > > +                                        unsigned int *pniov, size_t 
> > > size);
> > > +    void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec 
> > > **piov,
> > > +                                         unsigned int *pniov);
> > >      void        (*push_and_notify)(V9fsPDU *pdu);
> > >  };
> > >  
> > > diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
> > > index 273425b..27a4a32 100644
> > > --- a/hw/9pfs/virtio-9p-device.c
> > > +++ b/hw/9pfs/virtio-9p-device.c
> > > @@ -171,26 +171,34 @@ static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, 
> > > size_t offset,
> > >      return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, 
> > > fmt, ap);
> > >  }
> > >  
> > > -static void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
> > > -                                     unsigned int *pniov, bool is_write)
> > > +/* The size parameter is used by other transports. Do not drop it. */
> > > +static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec 
> > > **piov,
> > > +                                        unsigned int *pniov, size_t size)
> > >  {
> > >      V9fsState *s = pdu->s;
> > >      V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> > >      VirtQueueElement *elem = v->elems[pdu->idx];
> > >  
> > > -    if (is_write) {
> > > -        *piov = elem->out_sg;
> > > -        *pniov = elem->out_num;
> > > -    } else {
> > > -        *piov = elem->in_sg;
> > > -        *pniov = elem->in_num;
> > > -    }
> > > +    *piov = elem->in_sg;
> > > +    *pniov = elem->in_num;
> > > +}
> > > +
> > > +static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec 
> > > **piov,
> > > +                                         unsigned int *pniov)
> > > +{
> > > +    V9fsState *s = pdu->s;
> > > +    V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> > > +    VirtQueueElement *elem = v->elems[pdu->idx];
> > > +
> > > +    *piov = elem->out_sg;
> > > +    *pniov = elem->out_num;
> > >  }
> > >  
> > >  static const struct V9fsTransport virtio_9p_transport = {
> > >      .pdu_vmarshal = virtio_pdu_vmarshal,
> > >      .pdu_vunmarshal = virtio_pdu_vunmarshal,
> > > -    .init_iov_from_pdu = virtio_init_iov_from_pdu,
> > > +    .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu,
> > > +    .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu,
> > >      .push_and_notify = virtio_9p_push_and_notify,
> > >  };
> > >    
> > 
> > 
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