Re: [Qemu-devel] [PATCH 12/12 v11] introduce a new monitor command 'dump-guest-memory' to dump guest's memory

[Wen Congyang <wency@cn.fujitsu.com>]

At 03/26/2012 06:06 PM, Wen Congyang Wrote:
> The command's usage:
>    dump [-p] protocol [begin] [length]
> The supported protocol can be file or fd:
> 1. file: the protocol starts with "file:", and the following string is
>    the file's path.
> 2. fd: the protocol starts with "fd:", and the following string is the
>    fd's name.
> 
> Note:
>   1. If you want to use gdb to process the core, please specify -p option.
>      The reason why the -p option is not default is:
>        a. guest machine in a catastrophic state can have corrupted memory,
>           which we cannot trust.
>        b. The guest machine can be in read-mode even if paging is enabled.
>           For example: the guest machine uses ACPI to sleep, and ACPI sleep
>           state goes in real-mode.
>   2. This command doesn't support the fd that is is associated with a pipe,
>      socket, or FIFO(lseek will fail with such fd).
>   3. If you don't want to dump all guest's memory, please specify the start
>      physical address and the length.
> 
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> ---
>  Makefile.target  |    2 +-
>  dump.c           |  827 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  elf.h            |    5 +
>  hmp-commands.hx  |   28 ++
>  hmp.c            |   22 ++
>  hmp.h            |    1 +
>  memory_mapping.c |   27 ++
>  memory_mapping.h |    3 +
>  qapi-schema.json |   34 +++
>  qmp-commands.hx  |   38 +++
>  10 files changed, 986 insertions(+), 1 deletions(-)
>  create mode 100644 dump.c

<cut>

> +/* write the memroy to vmcore. 1 page per I/O. */
> +static int write_memory(DumpState *s, RAMBlock *block, ram_addr_t start,
> +                        target_phys_addr_t *offset, int64_t size)
> +{
> +    int i, ret;

The type of i should be int64_t. Otherwise,  i * TARGET_PAGE_SIZE
may be overflow.

I will resend this patch.

Thanks
Wen Congyang

> +
> +    for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
> +        ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
> +                         TARGET_PAGE_SIZE, offset);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +    }
> +
> +    if ((size % TARGET_PAGE_SIZE) != 0) {
> +        ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
> +                         size % TARGET_PAGE_SIZE, offset);
> +        if (ret < 0) {
> +            return ret;
> +        }
> +    }
> +
> +    return 0;
> +}
> +