Re: [Qemu-devel] [PATCH] dump: do not dump non-existent guest memory

[Laurent Vivier]

On 11/09/2017 15:26, Cornelia Huck wrote:
> It does not really make sense to dump memory that is not there.
> 
> Moreover, that fixes a segmentation fault when calling dump-guest-memory
> with no filter for a machine with no memory defined.
> 
> New behaviour is:
> 
> (qemu) dump-guest-memory /dev/null
> dump: no guest memory to dump
> (qemu) dump-guest-memory /dev/null 0 4096
> dump: no guest memory to dump
> 
> Signed-off-by: Cornelia Huck <address@hidden>
> ---
> 
> Another unmaintained file. Joy. cc:ing some more-or-less random folks.
> 
> ---
>  dump.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/dump.c b/dump.c
> index a79773d0f7..d2093e141b 100644
> --- a/dump.c
> +++ b/dump.c
> @@ -1536,6 +1536,12 @@ static void dump_init(DumpState *s, int fd, bool 
> has_format,
>      fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
>  #endif
>  
> +    /* it does not make sense to dump non-existent memory */
> +    if (!s->total_size) {
> +        error_setg(errp, "dump: no guest memory to dump");
> +        goto cleanup;
> +    }
> +
>      s->start = get_start_block(s);
>      if (s->start == -1) {
>          error_setg(errp, QERR_INVALID_PARAMETER, "begin");
> 

We need to update test-hmp, as with this change dump-guest-memory will
do nothing with none machine, as by default memory size is 0 MB (I'm
working on that)

Tested-by: Laurent Vivier <address@hidden>
Reviewed-by: Laurent Vivier <address@hidden>