Re: [PATCH 24/27] tools/libx{c, l}: [RFC] Introduce restore_callbacks.checkpoint()

[Yang Hongyang <yanghy@cn.fujitsu.com>]

On 06/15/2015 09:44 PM, Andrew Cooper wrote:
> And call it when a checkpoint record is found in the libxc stream.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Ian Campbell <Ian.Campbell@citrix.com>
> CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> CC: Wei Liu <wei.liu2@citrix.com>
> ---
>   tools/libxc/include/xenguest.h     |    3 +++
>   tools/libxc/xc_sr_restore.c        |   15 ++++++++++++++-
>   tools/libxl/libxl_save_msgs_gen.pl |    2 +-
>   3 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libxc/include/xenguest.h b/tools/libxc/include/xenguest.h
> index 7581263..b0d27ed 100644
> --- a/tools/libxc/include/xenguest.h
> +++ b/tools/libxc/include/xenguest.h
> @@ -102,6 +102,9 @@ struct restore_callbacks {
>       int (*toolstack_restore)(uint32_t domid, const uint8_t *buf,
>               uint32_t size, void* data);
>
> +    /* A checkpoint record has been found in the stream */

Describe the return value, e.g:
2 failover
1 success
0 error

> +    int (*checkpoint)(void* data);
> +
>       /* to be provided as the last argument to each callback function */
>       void* data;
>   };
> diff --git a/tools/libxc/xc_sr_restore.c b/tools/libxc/xc_sr_restore.c
> index 9e27dba..5e0f817 100644
> --- a/tools/libxc/xc_sr_restore.c
> +++ b/tools/libxc/xc_sr_restore.c
> @@ -1,5 +1,7 @@
>   #include <arpa/inet.h>
>
> +#include <assert.h>
> +
>   #include "xc_sr_common.h"
>
>   /*
> @@ -472,7 +474,7 @@ static int handle_page_data(struct xc_sr_context *ctx, struct xc_sr_record *rec)
>   static int handle_checkpoint(struct xc_sr_context *ctx)
>   {
>       xc_interface *xch = ctx->xch;
> -    int rc = 0;
> +    int rc = 0, ret;
>       unsigned i;
>
>       if ( !ctx->restore.checkpointed )
> @@ -482,6 +484,13 @@ static int handle_checkpoint(struct xc_sr_context *ctx)
>           goto err;
>       }
>
> +    ret = ctx->restore.callbacks->checkpoint(ctx->restore.callbacks->data);

Should check whether we need to failover.

> +    if ( ret )
> +    {
> +        rc = -1;
> +        goto err;
> +    }
> +
>       if ( ctx->restore.buffer_all_records )
>       {
>           IPRINTF("All records buffered");
> @@ -735,6 +744,10 @@ int xc_domain_restore2(xc_interface *xch, int io_fd, uint32_t dom,
>       ctx.restore.checkpointed = checkpointed_stream;
>       ctx.restore.callbacks = callbacks;
>
> +    /* Sanity checks for callbacks. */
> +    if (checkpointed_stream)
> +        assert(callbacks->checkpoint);
> +
>       IPRINTF("In experimental %s", __func__);
>       DPRINTF("fd %d, dom %u, hvm %u, pae %u, superpages %d"
>               ", checkpointed_stream %d", io_fd, dom, hvm, pae,
> diff --git a/tools/libxl/libxl_save_msgs_gen.pl b/tools/libxl/libxl_save_msgs_gen.pl
> index 6b4b65e..36b279e 100755
> --- a/tools/libxl/libxl_save_msgs_gen.pl
> +++ b/tools/libxl/libxl_save_msgs_gen.pl
> @@ -25,7 +25,7 @@ our @msgs = (
>                                                   'unsigned long', 'total'] ],
>       [  3, 'scxA',   "suspend", [] ],
>       [  4, 'scxA',   "postcopy", [] ],
> -    [  5, 'scxA',   "checkpoint", [] ],
> +    [  5, 'srcxA',   "checkpoint", [] ],
>       [  6, 'scxA',   "switch_qemu_logdirty",  [qw(int domid
>                                                 unsigned enable)] ],
>       #                toolstack_save          done entirely `by hand'
>

-- 
Thanks,
Yang.