Re: [v6][PATCH 3/7] tools/libxc: check if mmio BAR is out of reserved device memory maps

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

On 2014/9/11 5:37, Tian, Kevin wrote:
>> From: Chen, Tiejun
>> Sent: Tuesday, September 09, 2014 10:50 PM
>>
>> We need to avoid allocating MMIO BAR conflicting to all reserved device
>> memory range.
>
> besides checking MMIO BAR confliction, you also need check guest memory
> confliction with reserved device memory ranges.

Kexin,

In patch #6, hvmloader: check to reserved device memory maps in e820, 
we'll lookup the entire e820 table to check if RMRR is overlapping with 
all recorded ranges in e820, so I think that already cover this case, right?

>
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>>
>> diff --git a/tools/libxc/xc_hvm_build_x86.c b/tools/libxc/xc_hvm_build_x86.c
>> index c81a25b..299e33a 100644
>> --- a/tools/libxc/xc_hvm_build_x86.c
>> +++ b/tools/libxc/xc_hvm_build_x86.c
>> @@ -239,6 +239,73 @@ static int check_mmio_hole(uint64_t start, uint64_t
>> memsize,
>>           return 1;
>>   }
>>
>> +/*
>> + * Check whether there exists mmio overplap with the reserved device
>> + * memory map
>> + */
>> +static int check_rdm_overlap(xc_interface *xch, uint64_t mmio_start,
>> +                             uint64_t mmio_size)
>> +{
>> +    struct xen_mem_reserved_device_memory *map = NULL;
>
> If there are multiple callers of this call, better to move the structure out of
> this function to avoid multiple calls.

Good point.

+/* Record reserved device memory. */
+static struct xen_mem_reserved_device_memory *xmrdm = NULL;
+


>
>> +    uint64_t rdm_start = 0, rdm_end = 0;
>> +    unsigned int i = 0;
>> +    int rc = 0;
>> +    /* Assume we have one entry if not enough we'll expand.*/
>> +    uint32_t nr_entries = 1;

[snip]

>>       }
>>
>> +    rc = check_rdm_overlap(xch, mmio_start, mmio_start);
>
> mmio_start -> mmio_size.

Fixed and thanks a lot.

Thanks
Tiejun

>
>> +    if ( rc < 0 )
>> +        goto error_out;
>> +
>>       for ( i = 0; i < nr_pages; i++ )
>>           page_array[i] = i;
>>       for ( i = mmio_start >> PAGE_SHIFT; i < nr_pages; i++ )
>> --
>> 1.9.1
>
>