On Tue, Oct 11, 2016 at 06:18:32PM +0100, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > Convert the sbuf structure to a VMStateDescription. > Note this uses the VMSTATE_WITH_TMP mechanism to calculate > and reload the offsets based on the pointers. > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> slirp/sbuf.h | 4 +-
> slirp/slirp.c | 116
> ++++++++++++++++++++++++++++++++++++++--------------------
> 2 files changed, 78 insertions(+), 42 deletions(-)
>
> diff --git a/slirp/sbuf.h b/slirp/sbuf.h
> index efcec39..a722ecb 100644
> --- a/slirp/sbuf.h
> +++ b/slirp/sbuf.h
> @@ -12,8 +12,8 @@
> #define sbspace(sb) ((sb)->sb_datalen - (sb)->sb_cc)
>
> struct sbuf {
> - u_int sb_cc; /* actual chars in buffer */
> - u_int sb_datalen; /* Length of data */
> + uint32_t sb_cc; /* actual chars in buffer */
> + uint32_t sb_datalen; /* Length of data */
> char *sb_wptr; /* write pointer. points to where the next
> * bytes should be written in the sbuf */
> char *sb_rptr; /* read pointer. points to where the next
> diff --git a/slirp/slirp.c b/slirp/slirp.c
> index 6276315..2f7802e 100644
> --- a/slirp/slirp.c
> +++ b/slirp/slirp.c
> @@ -1185,19 +1185,72 @@ static const VMStateDescription vmstate_slirp_tcp = {
> }
> };
>
> -static void slirp_sbuf_save(QEMUFile *f, struct sbuf *sbuf)
> +/* The sbuf has a pair of pointers that are migrated as offsets;
> + * we calculate the offsets and restore the pointers using
> + * pre_save/post_load on a tmp structure.
> + */
> +struct sbuf_tmp {
> + struct sbuf *parent;
> + uint32_t roff, woff;
> +};
> +
> +static void sbuf_tmp_pre_save(void *opaque)
> +{
> + struct sbuf_tmp *tmp = opaque;
> + tmp->woff = tmp->parent->sb_wptr - tmp->parent->sb_data;
> + tmp->roff = tmp->parent->sb_rptr - tmp->parent->sb_data;
> +}
> +
> +static int sbuf_tmp_post_load(void *opaque, int version)
> {
> - uint32_t off;
> -
> - qemu_put_be32(f, sbuf->sb_cc);
> - qemu_put_be32(f, sbuf->sb_datalen);
> - off = (uint32_t)(sbuf->sb_wptr - sbuf->sb_data);
> - qemu_put_sbe32(f, off);
> - off = (uint32_t)(sbuf->sb_rptr - sbuf->sb_data);
> - qemu_put_sbe32(f, off);
> - qemu_put_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
> + struct sbuf_tmp *tmp = opaque;
> + uint32_t requested_len = tmp->parent->sb_datalen;
> +
> + /* Allocate the buffer space used by the field after the tmp */
> + sbreserve(tmp->parent, tmp->parent->sb_datalen);
> +
> + if (tmp->parent->sb_datalen != requested_len) {
> + return -ENOMEM;
> + }
> + if (tmp->woff >= requested_len ||
> + tmp->roff >= requested_len) {
> + error_report("invalid sbuf offsets r/w=%u/%u len=%u",
> + tmp->roff, tmp->woff, requested_len);
> + return -EINVAL;
> + }
> +
> + tmp->parent->sb_wptr = tmp->parent->sb_data + tmp->woff;
> + tmp->parent->sb_rptr = tmp->parent->sb_data + tmp->roff;
> +
> + return 0;
> }
>
> +
> +static const VMStateDescription vmstate_slirp_sbuf_tmp = {
> + .name = "slirp-sbuf-tmp",
> + .post_load = sbuf_tmp_post_load,
> + .pre_save = sbuf_tmp_pre_save,
> + .version_id = 0,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT32(woff, struct sbuf_tmp),
> + VMSTATE_UINT32(roff, struct sbuf_tmp),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static const VMStateDescription vmstate_slirp_sbuf = {
> + .name = "slirp-sbuf",
> + .version_id = 0,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT32(sb_cc, struct sbuf),
> + VMSTATE_UINT32(sb_datalen, struct sbuf),
> + VMSTATE_WITH_TMP(struct sbuf, struct sbuf_tmp,
> vmstate_slirp_sbuf_tmp),
> + VMSTATE_VBUFFER_UINT32(sb_data, struct sbuf, 0, NULL, 0, sb_datalen),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +
> static void slirp_socket_save(QEMUFile *f, struct socket *so)
> {
> qemu_put_be32(f, so->so_urgc);
> @@ -1225,8 +1278,9 @@ static void slirp_socket_save(QEMUFile *f, struct
> socket *so)
> qemu_put_byte(f, so->so_emu);
> qemu_put_byte(f, so->so_type);
> qemu_put_be32(f, so->so_state);
> - slirp_sbuf_save(f, &so->so_rcv);
> - slirp_sbuf_save(f, &so->so_snd);
> + /* TODO: Build vmstate at this level */
> + vmstate_save_state(f, &vmstate_slirp_sbuf, &so->so_rcv, 0);
> + vmstate_save_state(f, &vmstate_slirp_sbuf, &so->so_snd, 0);
> vmstate_save_state(f, &vmstate_slirp_tcp, so->so_tcpcb, 0);
> }
>
> @@ -1263,31 +1317,9 @@ static void slirp_state_save(QEMUFile *f, void *opaque)
> slirp_bootp_save(f, slirp);
> }
>
> -static int slirp_sbuf_load(QEMUFile *f, struct sbuf *sbuf)
> -{
> - uint32_t off, sb_cc, sb_datalen;
> -
> - sb_cc = qemu_get_be32(f);
> - sb_datalen = qemu_get_be32(f);
> -
> - sbreserve(sbuf, sb_datalen);
> -
> - if (sbuf->sb_datalen != sb_datalen)
> - return -ENOMEM;
> -
> - sbuf->sb_cc = sb_cc;
> -
> - off = qemu_get_sbe32(f);
> - sbuf->sb_wptr = sbuf->sb_data + off;
> - off = qemu_get_sbe32(f);
> - sbuf->sb_rptr = sbuf->sb_data + off;
> - qemu_get_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
> -
> - return 0;
> -}
> -
> static int slirp_socket_load(QEMUFile *f, struct socket *so, int version_id)
> {
> + int ret = 0;
> if (tcp_attach(so) < 0)
> return -ENOMEM;
>
> @@ -1324,11 +1356,15 @@ static int slirp_socket_load(QEMUFile *f, struct
> socket *so, int version_id)
> so->so_emu = qemu_get_byte(f);
> so->so_type = qemu_get_byte(f);
> so->so_state = qemu_get_be32(f);
> - if (slirp_sbuf_load(f, &so->so_rcv) < 0)
> - return -ENOMEM;
> - if (slirp_sbuf_load(f, &so->so_snd) < 0)
> - return -ENOMEM;
> - return vmstate_load_state(f, &vmstate_slirp_tcp, so->so_tcpcb, 0);
> + /* TODO: VMState at this level */
> + ret = vmstate_load_state(f, &vmstate_slirp_sbuf, &so->so_rcv, 0);
> + if (!ret) {
> + ret = vmstate_load_state(f, &vmstate_slirp_sbuf, &so->so_snd, 0);
> + }
> + if (!ret) {
> + ret = vmstate_load_state(f, &vmstate_slirp_tcp, so->so_tcpcb, 0);
> + }
> + return ret;
> }
>
> static void slirp_bootp_load(QEMUFile *f, Slirp *slirp)
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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