Re: [RFC][v3][PATCH 5/6] tools:libxc: check if mmio BAR is out of RMRR mappings

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 15/08/14 09:27, Tiejun Chen wrote:
> We need to avoid allocating MMIO BAR conficting to RMRR range.
>
> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
> ---
>  tools/libxc/xc_domain.c        | 26 ++++++++++++++++++++++++++
>  tools/libxc/xc_hvm_build_x86.c | 23 +++++++++++++++++++++++
>  tools/libxc/xenctrl.h          |  4 ++++
>  3 files changed, 53 insertions(+)
>
> diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
> index c67ac9a..8d011ef 100644
> --- a/tools/libxc/xc_domain.c
> +++ b/tools/libxc/xc_domain.c
> @@ -649,6 +649,32 @@ int xc_domain_set_memory_map(xc_interface *xch,
>  
>      return rc;
>  }
> +
> +int xc_get_rmrr_map(xc_interface *xch,

This function name should match the hypercall.  Perhaps
xc_reserved_device_memory_map() ?

> +                    struct e820entry entries[],
> +                    uint32_t max_entries)

This libxc function would be far more use if it took a single
xen_memory_map parameter, rather than splitting the return information
from Xen between one of the parameters and the return value.

~Andrew

> +{
> +    int rc;
> +    struct xen_memory_map memmap = {
> +        .nr_entries = max_entries
> +    };
> +    DECLARE_HYPERCALL_BOUNCE(entries, sizeof(struct e820entry) * max_entries,
> +                             XC_HYPERCALL_BUFFER_BOUNCE_OUT);
> +
> +    if ( !entries || xc_hypercall_bounce_pre(xch, entries) || max_entries <= 1)
> +        return -1;
> +
> +
> +    set_xen_guest_handle(memmap.buffer, entries);
> +
> +    rc = do_memory_op(xch, XENMEM_reserved_device_memory_map,
> +                      &memmap, sizeof(memmap));
> +
> +    xc_hypercall_bounce_post(xch, entries);
> +
> +    return rc ? rc : memmap.nr_entries;
> +}
> +
>  int xc_get_machine_memory_map(xc_interface *xch,
>                                struct e820entry entries[],
>                                uint32_t max_entries)
> diff --git a/tools/libxc/xc_hvm_build_x86.c b/tools/libxc/xc_hvm_build_x86.c
> index c81a25b..2196cdb 100644
> --- a/tools/libxc/xc_hvm_build_x86.c
> +++ b/tools/libxc/xc_hvm_build_x86.c
> @@ -262,6 +262,8 @@ static int setup_guest(xc_interface *xch,
>      int claim_enabled = args->claim_enabled;
>      xen_pfn_t special_array[NR_SPECIAL_PAGES];
>      xen_pfn_t ioreq_server_array[NR_IOREQ_SERVER_PAGES];
> +    struct e820entry map[E820MAX];
> +    uint64_t rmrr_start = 0, rmrr_end = 0;
>  
>      if ( nr_pages > target_pages )
>          pod_mode = XENMEMF_populate_on_demand;
> @@ -300,6 +302,27 @@ static int setup_guest(xc_interface *xch,
>          goto error_out;
>      }
>  
> +    /* We should check if mmio range is out of RMRR mapping. */
> +    rc = xc_get_rmrr_map(xch, map, E820MAX);
> +    if (rc < 0)
> +    {
> +        PERROR("Could not get RMRR info on domain");
> +    }
> +    else if ( rc )
> +    {
> +        for ( i = 0; i < rc; i++ )
> +        {
> +            rmrr_start = map[i].addr;
> +            rmrr_end = map[i].addr + map[i].size + 1;
> +            if ( check_mmio_hole(rmrr_start, map[i].size + 1, mmio_start, mmio_size) )
> +            {
> +                PERROR("MMIO: [%lx]<->[%lx] overlap RMRR [%lx]<->[%lx]\n",
> +                       mmio_start, (mmio_start + mmio_size), rmrr_start, rmrr_end);
> +                goto error_out;
> +            }
> +        }
> +    }
> +
>      for ( i = 0; i < nr_pages; i++ )
>          page_array[i] = i;
>      for ( i = mmio_start >> PAGE_SHIFT; i < nr_pages; i++ )
> diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
> index 1c5d0db..6d3b135 100644
> --- a/tools/libxc/xenctrl.h
> +++ b/tools/libxc/xenctrl.h
> @@ -1270,6 +1270,10 @@ int xc_domain_set_memory_map(xc_interface *xch,
>  int xc_get_machine_memory_map(xc_interface *xch,
>                                struct e820entry entries[],
>                                uint32_t max_entries);
> +
> +int xc_get_rmrr_map(xc_interface *xch,
> +                    struct e820entry entries[],
> +                    uint32_t max_entries);
>  #endif
>  int xc_domain_set_time_offset(xc_interface *xch,
>                                uint32_t domid,