On Mon, 28 Nov 2016 13:27:24 -0800
Stefano Stabellini <sstabell...@kernel.org> 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 <sstabell...@kernel.org>
> ---
Reviewed-by: Greg Kurz <gr...@kaod.org>
> 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,
> };
>
