Re: [PATCH v4 13/23] libxl: use COMPARE_PCI() macro is_pci_in_array()...

[Oleksandr Andrushchenko <Oleksandr_Andrushchenko@epam.com>]

Hi, Paul!

On 11/24/20 10:01 AM, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@amazon.com>
>
> ... rather than an open-coded equivalent.
>
> This patch tidies up the is_pci_in_array() function, making it take a single
> 'libxl_device_pci' argument rather than separate domain, bus, device and
> function arguments. The already-available COMPARE_PCI() macro can then be
> used and it is also modified to return 'bool' rather than 'int'.
>
> The patch also modifies libxl_pci_assignable() to use is_pci_in_array() rather
> than a separate open-coded equivalent, and also modifies it to return a
> 'bool' rather than an 'int'.
>
> NOTE: The COMPARE_PCI() macro is also fixed to include the 'domain' in its
>        comparison, which should always have been the case.
>
> Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Thank you,

Oleksandr

> ---
> Cc: Ian Jackson <iwj@xenproject.org>
> Cc: Wei Liu <wl@xen.org>
> ---
>   tools/libs/light/libxl_internal.h |  7 ++++---
>   tools/libs/light/libxl_pci.c      | 38 +++++++++++++-------------------------
>   2 files changed, 17 insertions(+), 28 deletions(-)
>
> diff --git a/tools/libs/light/libxl_internal.h b/tools/libs/light/libxl_internal.h
> index ecee61b541..02f8a3179c 100644
> --- a/tools/libs/light/libxl_internal.h
> +++ b/tools/libs/light/libxl_internal.h
> @@ -4746,9 +4746,10 @@ void libxl__xcinfo2xlinfo(libxl_ctx *ctx,
>    * devices have same identifier. */
>   #define COMPARE_DEVID(a, b) ((a)->devid == (b)->devid)
>   #define COMPARE_DISK(a, b) (!strcmp((a)->vdev, (b)->vdev))
> -#define COMPARE_PCI(a, b) ((a)->func == (b)->func &&    \
> -                           (a)->bus == (b)->bus &&      \
> -                           (a)->dev == (b)->dev)
> +#define COMPARE_PCI(a, b) ((a)->domain == (b)->domain && \
> +                           (a)->bus == (b)->bus &&       \
> +                           (a)->dev == (b)->dev &&       \
> +                           (a)->func == (b)->func)
>   #define COMPARE_USB(a, b) ((a)->ctrl == (b)->ctrl && \
>                              (a)->port == (b)->port)
>   #define COMPARE_USBCTRL(a, b) ((a)->devid == (b)->devid)
> diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
> index 5a3352c2ec..e0b616fe18 100644
> --- a/tools/libs/light/libxl_pci.c
> +++ b/tools/libs/light/libxl_pci.c
> @@ -336,24 +336,17 @@ retry_transaction2:
>       return 0;
>   }
>   
> -static int is_pci_in_array(libxl_device_pci *assigned, int num_assigned,
> -                           int dom, int bus, int dev, int func)
> +static bool is_pci_in_array(libxl_device_pci *pcis, int num,
> +                            libxl_device_pci *pci)
>   {
>       int i;
>   
> -    for(i = 0; i < num_assigned; i++) {
> -        if ( assigned[i].domain != dom )
> -            continue;
> -        if ( assigned[i].bus != bus )
> -            continue;
> -        if ( assigned[i].dev != dev )
> -            continue;
> -        if ( assigned[i].func != func )
> -            continue;
> -        return 1;
> +    for (i = 0; i < num; i++) {
> +        if (COMPARE_PCI(pci, &pcis[i]))
> +            break;
>       }
>   
> -    return 0;
> +    return i < num;
>   }
>   
>   /* Write the standard BDF into the sysfs path given by sysfs_path. */
> @@ -1487,21 +1480,17 @@ int libxl_device_pci_add(libxl_ctx *ctx, uint32_t domid,
>       return AO_INPROGRESS;
>   }
>   
> -static int libxl_pci_assignable(libxl_ctx *ctx, libxl_device_pci *pci)
> +static bool libxl_pci_assignable(libxl_ctx *ctx, libxl_device_pci *pci)
>   {
>       libxl_device_pci *pcis;
> -    int num, i;
> +    int num;
> +    bool assignable;
>   
>       pcis = libxl_device_pci_assignable_list(ctx, &num);
> -    for (i = 0; i < num; i++) {
> -        if (pcis[i].domain == pci->domain &&
> -            pcis[i].bus == pci->bus &&
> -            pcis[i].dev == pci->dev &&
> -            pcis[i].func == pci->func)
> -            break;
> -    }
> +    assignable = is_pci_in_array(pcis, num, pci);
>       libxl_device_pci_assignable_list_free(pcis, num);
> -    return i != num;
> +
> +    return assignable;
>   }
>   
>   static void device_pci_add_stubdom_wait(libxl__egc *egc,
> @@ -1834,8 +1823,7 @@ static void do_pci_remove(libxl__egc *egc, pci_remove_state *prs)
>           goto out_fail;
>       }
>   
> -    attached = is_pci_in_array(pcis, num, pci->domain,
> -                               pci->bus, pci->dev, pci->func);
> +    attached = is_pci_in_array(pcis, num, pci);
>       libxl_device_pci_list_free(pcis, num);
>   
>       rc = ERROR_INVAL;