Re: [PATCH v5 04/18] dump: Rework get_start_block

[Janis Schoetterl-Glausch]

On Thu, 2022-08-11 at 12:10 +0000, Janosch Frank wrote:
> get_start_block() returns the start address of the first memory block
> or -1.
> 
> With the GuestPhysBlock iterator conversion we don't need to set the
> start address and can therefore remove that code and the "start"
> DumpState struct member. The only functionality left is the validation
> of the start block so it only makes sense to re-name the function to
> validate_start_block()

Nit, since you don't return an address anymore, I find retaining the -
1/0 return value instead of true/false weird.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
> ---
>  dump/dump.c           | 20 ++++++--------------
>  include/sysemu/dump.h |  2 --
>  2 files changed, 6 insertions(+), 16 deletions(-)
> 
> diff --git a/dump/dump.c b/dump/dump.c
> index 340de5a1e7..e204912a89 100644
> --- a/dump/dump.c
> +++ b/dump/dump.c
> @@ -1500,30 +1500,22 @@ static void create_kdump_vmcore(DumpState *s, Error 
> **errp)
>      }
>  }
>  
> -static ram_addr_t get_start_block(DumpState *s)
> +static int validate_start_block(DumpState *s)
>  {
>      GuestPhysBlock *block;
>  
>      if (!s->has_filter) {
> -        s->next_block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
>          return 0;
>      }
>  
>      QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
> +        /* This block is out of the range */
>          if (block->target_start >= s->begin + s->length ||
>              block->target_end <= s->begin) {
> -            /* This block is out of the range */
>              continue;
>          }
> -
> -        s->next_block = block;
> -        if (s->begin > block->target_start) {
> -            s->start = s->begin - block->target_start;
> -        } else {
> -            s->start = 0;
> -        }
> -        return s->start;
> -    }
> +        return 0;
> +   }
>  
>      return -1;
>  }
> @@ -1670,8 +1662,8 @@ static void dump_init(DumpState *s, int fd, bool 
> has_format,
>          goto cleanup;
>      }
>  
> -    s->start = get_start_block(s);
> -    if (s->start == -1) {
> +    /* Is the filter filtering everything? */
> +    if (validate_start_block(s) == -1) {
>          error_setg(errp, QERR_INVALID_PARAMETER, "begin");
>          goto cleanup;
>      }
> diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
> index ffc2ea1072..7fce1d4af6 100644
> --- a/include/sysemu/dump.h
> +++ b/include/sysemu/dump.h
> @@ -166,8 +166,6 @@ typedef struct DumpState {
>      hwaddr memory_offset;
>      int fd;
>  
> -    GuestPhysBlock *next_block;
> -    ram_addr_t start;
>      bool has_filter;
>      int64_t begin;
>      int64_t length;