Re: [PATCH for-4.6 v2 7/8] python/xc: reinstate original implementation of next_bdf

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2015/7/28 1:45, Wei Liu wrote:
> I missed the fact that next_bdf is used to parsed user supplied
> strings when reviewing. The user supplied string is a NULL-terminated
> string separated by comma. User can supply several PCI devices in that
> string. There is, however, no delimiter for different devices, hence
> we can't change the syntax of that string.
>
> This patch reinstate the original implementation of next_bdf to
> preserve the original syntax. The last argument for xc_assign_device
> is always 0.
>
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> ---
> Cc: Tiejun Chen <tiejun.chen@intel.com>
>
> Tiejun, are you actually using this python binding? I don't think we

This change is just following to RMRR series but currently we don't use 
this. So its fine if you think this don't break any other usages.

Thanks
Tiejun

> have in tree user.
>
> If nobody is using it, I propose we remove this binding in next
> release.
>
> I don't have live example of that string. My analysis is based on
> reverse-engineering of original code.
> ---
>   tools/python/xen/lowlevel/xc/xc.c | 30 ++++++++++--------------------
>   1 file changed, 10 insertions(+), 20 deletions(-)
>
> diff --git a/tools/python/xen/lowlevel/xc/xc.c b/tools/python/xen/lowlevel/xc/xc.c
> index c8380d1..2c36eb2 100644
> --- a/tools/python/xen/lowlevel/xc/xc.c
> +++ b/tools/python/xen/lowlevel/xc/xc.c
> @@ -592,8 +592,7 @@ static int token_value(char *token)
>       return strtol(token, NULL, 16);
>   }
>
> -static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func,
> -                    int *flag)
> +static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func)
>   {
>       char *token;
>
> @@ -608,17 +607,8 @@ static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func,
>       *dev  = token_value(token);
>       token = strchr(token, ',') + 1;
>       *func  = token_value(token);
> -    token = strchr(token, ',') + 1;
> -    if ( token ) {
> -        *flag = token_value(token);
> -        *str = token + 1;
> -    }
> -    else
> -    {
> -        /* O means we take "strict" as our default policy. */
> -        *flag = 0;
> -        *str = NULL;
> -    }
> +    token = strchr(token, ',');
> +    *str = token ? token + 1 : NULL;
>
>       return 1;
>   }
> @@ -630,14 +620,14 @@ static PyObject *pyxc_test_assign_device(XcObject *self,
>       uint32_t dom;
>       char *pci_str;
>       int32_t sbdf = 0;
> -    int seg, bus, dev, func, flag;
> +    int seg, bus, dev, func;
>
>       static char *kwd_list[] = { "domid", "pci", NULL };
>       if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
>                                         &dom, &pci_str) )
>           return NULL;
>
> -    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
> +    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
>       {
>           sbdf = seg << 16;
>           sbdf |= (bus & 0xff) << 8;
> @@ -663,21 +653,21 @@ static PyObject *pyxc_assign_device(XcObject *self,
>       uint32_t dom;
>       char *pci_str;
>       int32_t sbdf = 0;
> -    int seg, bus, dev, func, flag;
> +    int seg, bus, dev, func;
>
>       static char *kwd_list[] = { "domid", "pci", NULL };
>       if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
>                                         &dom, &pci_str) )
>           return NULL;
>
> -    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
> +    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
>       {
>           sbdf = seg << 16;
>           sbdf |= (bus & 0xff) << 8;
>           sbdf |= (dev & 0x1f) << 3;
>           sbdf |= (func & 0x7);
>
> -        if ( xc_assign_device(self->xc_handle, dom, sbdf, flag) != 0 )
> +        if ( xc_assign_device(self->xc_handle, dom, sbdf, 0) != 0 )
>           {
>               if (errno == ENOSYS)
>                   sbdf = -1;
> @@ -696,14 +686,14 @@ static PyObject *pyxc_deassign_device(XcObject *self,
>       uint32_t dom;
>       char *pci_str;
>       int32_t sbdf = 0;
> -    int seg, bus, dev, func, flag;
> +    int seg, bus, dev, func;
>
>       static char *kwd_list[] = { "domid", "pci", NULL };
>       if ( !PyArg_ParseTupleAndKeywords(args, kwds, "is", kwd_list,
>                                         &dom, &pci_str) )
>           return NULL;
>
> -    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func, &flag) )
> +    while ( next_bdf(&pci_str, &seg, &bus, &dev, &func) )
>       {
>           sbdf = seg << 16;
>           sbdf |= (bus & 0xff) << 8;
>