Re: [Qemu-devel] [PATCH v4 09/11] DumpState: adding total_size and written_size fields

[Fam Zheng <famz@redhat.com>]

On Tue, 12/01 21:28, Peter Xu wrote:
> Here, total_size is the size in bytes to be dumped (raw data, which
> means before compression), while written_size are bytes handled (raw
> size too).
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  dump.c                | 32 ++++++++++++++++++++++++++++++++
>  include/sysemu/dump.h |  9 +++++++++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/dump.c b/dump.c
> index 5b040b7..daa1f2c 100644
> --- a/dump.c
> +++ b/dump.c
> @@ -333,6 +333,8 @@ static void write_data(DumpState *s, void *buf, int length, Error **errp)
>      if (ret < 0) {
>          error_setg(errp, "dump: failed to save memory");
>      }
> +
> +    s->written_size += length;

If (ret < 0), the incremental is inaccurate, do we want an accurate
written_size in that case? I.e. put this in "else" branch?

>  }
>  
>  /* write the memory to vmcore. 1 page per I/O. */
> @@ -1301,6 +1303,7 @@ static void write_dump_pages(DumpState *s, Error **errp)
>                  goto out;
>              }
>          }
> +        s->written_size += TARGET_PAGE_SIZE;

The same question applies here.

>      }
>  
>      ret = write_cache(&page_desc, NULL, 0, true);
> @@ -1433,6 +1436,30 @@ bool dump_in_progress(void)
>      return (state->status == DUMP_STATUS_ACTIVE);
>  }
>  
> +/* calculate total size of memory to be dumped (taking filter into
> + * acoount.) */
> +static size_t dump_calculate_size(DumpState *s)

Is size_t big enough for 64 bit guest on 32 bit host (with 4 bytes size_t)?

> +{
> +    GuestPhysBlock *block;
> +    int64_t size = 0, total = 0, left = 0, right = 0;
> +
> +    QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
> +        if (s->has_filter) {
> +            /* calculate the overlapped region. */
> +            left = MAX(s->begin, block->target_start);
> +            right = MIN(s->begin + s->length, block->target_end);
> +            size = right - left;
> +            size = size > 0 ? size : 0;
> +        } else {
> +            /* count the whole region in */
> +            size = (block->target_end - block->target_start);
> +        }
> +        total += size;
> +    }
> +
> +    return total;
> +}
> +
>  static void dump_init(DumpState *s, int fd, bool has_format,
>                        DumpGuestMemoryFormat format, bool paging, bool has_filter,
>                        int64_t begin, int64_t length, Error **errp)
> @@ -1444,6 +1471,7 @@ static void dump_init(DumpState *s, int fd, bool has_format,
>  
>      s->has_format = has_format;
>      s->format = format;
> +    s->written_size = 0;
>  
>      /* kdump-compressed is conflict with paging and filter */
>      if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
> @@ -1475,6 +1503,10 @@ static void dump_init(DumpState *s, int fd, bool has_format,
>  
>      guest_phys_blocks_init(&s->guest_phys_blocks);
>      guest_phys_blocks_append(&s->guest_phys_blocks);
> +    s->total_size = dump_calculate_size(s);
> +#ifdef DEBUG_DUMP_GUEST_MEMORY
> +    fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
> +#endif
>  
>      s->start = get_start_block(s);
>      if (s->start == -1) {
> diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
> index 31930c6..9c5a46b 100644
> --- a/include/sysemu/dump.h
> +++ b/include/sysemu/dump.h
> @@ -189,6 +189,15 @@ typedef struct DumpState {
>      bool has_format;              /* whether format is provided */
>      DumpGuestMemoryFormat format; /* valid only if has_format == true */
>      QemuThread dump_thread;       /* thread for detached dump */
> +
> +    size_t total_size;          /* total memory size (in bytes) to
> +                                 * be dumped. When filter is
> +                                 * enabled, this will only count
> +                                 * those to be written. */
> +    size_t written_size;        /* written memory size (in bytes),
> +                                 * this could be used to calculate
> +                                 * how many work we have

s/many/much/

> +                                 * finished. */
>  } DumpState;
>  
>  uint16_t cpu_to_dump16(DumpState *s, uint16_t val);
> -- 
> 2.4.3
>