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Re: [Qemu-devel] [PATCH v6 02/11] dump: Add API to write header of flatt
From: |
Laszlo Ersek |
Subject: |
Re: [Qemu-devel] [PATCH v6 02/11] dump: Add API to write header of flatten format |
Date: |
Mon, 06 Jan 2014 18:15:11 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131118 Thunderbird/17.0.11 |
On 01/05/14 08:27, Qiao Nuohan wrote:
> flatten format may be used when writing kdump-compressed format. The format is
> also used by makedumpfile, you can refer to the following URL to get more
> detailed information about flatten format of kdump-compressed format:
> http://sourceforge.net/projects/makedumpfile/
>
> The two functions here are used to write start flat header and end flat header
> to vmcore, and they will be called later if flatten format is used.
>
> struct MakedumpfileHeader stored at the head of vmcore is used to indicate the
> vmcore is in flatten format.
>
> struct MakedumpfileHeader {
> char signature[16]; /* = "makedumpfile" */
> int64_t type; /* = 1 */
> int64_t version; /* = 1 */
> };
>
> And struct MakedumpfileDataHeader, with offset and buf_size set to -1, is used
> to indicate the end of vmcore in flatten format.
>
> struct MakedumpfileDataHeader {
> int64_t offset; /* = -1 */
> int64_t buf_size; /* = -1 */
> };
>
> Signed-off-by: Qiao Nuohan <address@hidden>
> ---
> dump.c | 40 ++++++++++++++++++++++++++++++++++++++++
> include/sysemu/dump.h | 17 +++++++++++++++++
> 2 files changed, 57 insertions(+), 0 deletions(-)
>
> diff --git a/dump.c b/dump.c
> index 1fa12a2..89baeab 100644
> --- a/dump.c
> +++ b/dump.c
> @@ -686,6 +686,46 @@ static int create_vmcore(DumpState *s)
> return 0;
> }
>
> +static int write_start_flat_header(int fd)
> +{
> + char buf[MAX_SIZE_MDF_HEADER];
> + MakedumpfileHeader mh;
> +
> + memset(&mh, 0, sizeof(mh));
> + strncpy(mh.signature, MAKEDUMPFILE_SIGNATURE,
> + strlen(MAKEDUMPFILE_SIGNATURE));
> +
> + mh.type = cpu_to_be64(TYPE_FLAT_HEADER);
> + mh.version = cpu_to_be64(VERSION_FLAT_HEADER);
> +
> + memset(buf, 0, sizeof(buf));
> + memcpy(buf, &mh, sizeof(mh));
> +
> + size_t written_size;
> + written_size = qemu_write_full(fd, buf, sizeof(buf));
> + if (written_size != sizeof(buf)) {
> + return -1;
> + }
> +
> + return 0;
> +}
I might have coded this in different style (using a union etc), but
that's not your problem :)
> [...]
Reviewed-by: Laszlo Ersek <address@hidden>
- [Qemu-devel] [PATCH v6 05/11] dump: add support for lzo/snappy, (continued)
- [Qemu-devel] [PATCH v6 03/11] dump: Add API to write vmcore, Qiao Nuohan, 2014/01/05
- [Qemu-devel] [PATCH v6 11/11] Add 'query-dump-guest-memory-capability' command, Qiao Nuohan, 2014/01/05
- [Qemu-devel] [PATCH v6 02/11] dump: Add API to write header of flatten format, Qiao Nuohan, 2014/01/05
- Re: [Qemu-devel] [PATCH v6 02/11] dump: Add API to write header of flatten format,
Laszlo Ersek <=
- [Qemu-devel] [PATCH v6 04/11] dump: Add API to write elf notes to buffer, Qiao Nuohan, 2014/01/05
- [Qemu-devel] [PATCH v6 10/11] dump: Make kdump-compressed format available for 'dump-guest-memory', Qiao Nuohan, 2014/01/05
- [Qemu-devel] [PATCH v6 08/11] dump: Add APIs to operate DataCache, Qiao Nuohan, 2014/01/05
- [Qemu-devel] [PATCH v6 09/11] dump: Add API to write dump pages, Qiao Nuohan, 2014/01/05