Re: [PATCH v12.2 09/15] vpci/header: program p2m with guest BAR view

[Stewart Hildebrand <stewart.hildebrand@xxxxxxx>]

On 1/15/24 14:44, Stewart Hildebrand wrote:
> diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
> index feccd070ddd0..8483404c5e91 100644
> --- a/xen/drivers/vpci/header.c
> +++ b/xen/drivers/vpci/header.c
> @@ -41,13 +42,24 @@ static int cf_check map_range(
>      unsigned long s, unsigned long e, void *data, unsigned long *c)
>  {
>      const struct map_data *map = data;
> +    /* Start address of the BAR as seen by the guest. */
> +    unsigned long start_gfn = PFN_DOWN(map->bar->guest_addr);
> +    /* Physical start address of the BAR. */
> +    unsigned long start_mfn = PFN_DOWN(map->bar->addr);
>      int rc;
>  
>      for ( ; ; )
>      {
>          unsigned long size = e - s + 1;
> +        /*
> +         * Ranges to be mapped don't always start at the BAR start address, 
> as
> +         * there can be holes or partially consumed ranges. Account for the
> +         * offset of the current address from the BAR start.
> +         */
> +        unsigned long map_mfn = start_mfn + s - start_gfn;
> +        unsigned long m_end = map_mfn + size - 1;
>  
> -        if ( !iomem_access_permitted(map->d, s, e) )
> +        if ( !iomem_access_permitted(map->d, map_mfn, m_end) )

Nit: since this check will now use map_mfn and m_end...

>          {
>              printk(XENLOG_G_WARNING
>                     "%pd denied access to MMIO range [%#lx, %#lx]\n",
>                     map->d, s, e);

... I'd like to also update the arguments passed to this print statement.