Re: [Qemu-devel] [PATCH V8 2/5] Adding utility function net_checksum_add_iov() for iovec checksum calculation

[Stefan Hajnoczi <stefanha@gmail.com>]

On Fri, Dec 07, 2012 at 01:15:06PM +0200, Dmitry Fleytman wrote:
> Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
> Signed-off-by: Yan Vugenfirer <yan@daynix.com>
> ---
>  iov.h          |  5 +++++
>  net/checksum.c | 28 ++++++++++++++++++++++++++++
>  net/checksum.h |  8 ++++++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/iov.h b/iov.h
> index 34c8ec9..c184a80 100644
> --- a/iov.h
> +++ b/iov.h
> @@ -11,6 +11,9 @@

This file has been moved in qemu.git/master.  It is now
include/qemu/iov.h.

>   * the COPYING file in the top-level directory.
>   */
>  
> +#ifndef QEMU_IOV_H
> +#define QEMU_IOV_H
> +

This is already present in qemu.git/master.

>  #include "qemu-common.h"
>  
>  /**
> @@ -95,3 +98,5 @@ void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt,
>  unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt,
>                   const struct iovec *iov, unsigned int iov_cnt,
>                   size_t offset, size_t bytes);
> +
> +#endif /* QEMU_IOV_H */

Same here.  Just pointing out expected rebase conflicts you'll see for
the next revision of this series.

> diff --git a/net/checksum.c b/net/checksum.c
> index 4fa5563..9c813ff 100644
> --- a/net/checksum.c
> +++ b/net/checksum.c
> @@ -84,3 +84,31 @@ void net_checksum_calculate(uint8_t *data, int length)
>      data[14+hlen+csum_offset]   = csum >> 8;
>      data[14+hlen+csum_offset+1] = csum & 0xff;
>  }
> +
> +uint32_t
> +net_checksum_add_iov(const struct iovec *iov, const unsigned int iov_cnt,
> +                     uint32_t iov_off, uint32_t size)
> +{
> +    size_t iovec_off, buf_off;
> +    unsigned int i;
> +    uint32_t res = 0;
> +    uint32_t seq = 0;
> +
> +    iovec_off = 0;
> +    buf_off = 0;
> +    for (i = 0; i < iov_cnt && size; i++) {
> +        if (iov_off < (iovec_off + iov[i].iov_len)) {
> +            size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size);
> +            void *chunk_buf = iov[i].iov_base + (iov_off - iovec_off);
> +
> +            res += net_checksum_add_cont(len, chunk_buf, seq);
> +            seq += len;
> +
> +            buf_off += len;
> +            iov_off += len;
> +            size -= len;
> +        }
> +        iovec_off += iov[i].iov_len;
> +    }
> +    return res;
> +}
> diff --git a/net/checksum.h b/net/checksum.h
> index 171924c..e63c482 100644
> --- a/net/checksum.h
> +++ b/net/checksum.h
> @@ -19,6 +19,7 @@
>  #define QEMU_NET_CHECKSUM_H
>  
>  #include <stdint.h>
> +#include "iov.h"

iov.h is the wrong header file, you need struct iovec from
qemu-common.h.