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

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

On 2014/8/15 20:21, Andrew Cooper wrote:
> On 15/08/14 09:27, Tiejun Chen wrote:
>> We need to avoid allocating MMIO BAR conflicting 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() ?
>

Okay.

>> +                    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.

I can't understand why we do something specific here. Please take a look 
at xc_get_machine_memory_map(). So why did you think we should do this?

Thanks
Tiejun

>
> ~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,
>
>