Re: [PATCH v18 QEMU 02/18] vfio: Add function to unmap VFIO region

[Kirti Wankhede <kwankhede@nvidia.com>]

On 5/5/2020 11:46 AM, Philippe Mathieu-Daudé wrote:
> Hi Kirti,
> 
> On 5/5/20 12:44 AM, Kirti Wankhede wrote:
>> This function will be used for migration region.
>> Migration region is mmaped when migration starts and will be unmapped 
>> when
>> migration is complete.
>>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>   hw/vfio/common.c              | 20 ++++++++++++++++++++
>>   hw/vfio/trace-events          |  1 +
>>   include/hw/vfio/vfio-common.h |  1 +
>>   3 files changed, 22 insertions(+)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 0b3593b3c0c4..4a2f0d6a2233 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -983,6 +983,26 @@ int vfio_region_mmap(VFIORegion *region)
>>       return 0;
>>   }
>> +void vfio_region_unmap(VFIORegion *region)
>> +{
>> +    int i;
>> +
>> +    if (!region->mem) {
>> +        return;
>> +    }
>> +
>> +    for (i = 0; i < region->nr_mmaps; i++) {
> 
> I'd refactor this  block <...
>> +        
>> trace_vfio_region_unmap(memory_region_name(&region->mmaps[i].mem),
>> +                                region->mmaps[i].offset,
>> +                                region->mmaps[i].offset +
>> +                                region->mmaps[i].size - 1);
>> +        memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
>> +        munmap(region->mmaps[i].mmap, region->mmaps[i].size);
>> +        object_unparent(OBJECT(&region->mmaps[i].mem));
>> +        region->mmaps[i].mmap = NULL;
> 
> ...> into a helper and reuse it in vfio_region_mmap(). Well, actually 
> I'd factor it out from vfio_region_mmap() then reuse it here. Anyway 
> this is v18 so can be done later on top.
> 

Nevermind, this is not the last version, I'll do suggested change.

> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> 

Thanks,
Kirti

>> +    }
>> +}
>> +
>>   void vfio_region_exit(VFIORegion *region)
>>   {
>>       int i;
>> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
>> index b1ef55a33ffd..8cdc27946cb8 100644
>> --- a/hw/vfio/trace-events
>> +++ b/hw/vfio/trace-events
>> @@ -111,6 +111,7 @@ vfio_region_mmap(const char *name, unsigned long 
>> offset, unsigned long end) "Reg
>>   vfio_region_exit(const char *name, int index) "Device %s, region %d"
>>   vfio_region_finalize(const char *name, int index) "Device %s, region 
>> %d"
>>   vfio_region_mmaps_set_enabled(const char *name, bool enabled) 
>> "Region %s mmaps enabled: %d"
>> +vfio_region_unmap(const char *name, unsigned long offset, unsigned 
>> long end) "Region %s unmap [0x%lx - 0x%lx]"
>>   vfio_region_sparse_mmap_header(const char *name, int index, int 
>> nr_areas) "Device %s region %d: %d sparse mmap entries"
>>   vfio_region_sparse_mmap_entry(int i, unsigned long start, unsigned 
>> long end) "sparse entry %d [0x%lx - 0x%lx]"
>>   vfio_get_dev_region(const char *name, int index, uint32_t type, 
>> uint32_t subtype) "%s index %d, %08x/%0x8"
>> diff --git a/include/hw/vfio/vfio-common.h 
>> b/include/hw/vfio/vfio-common.h
>> index fd564209ac71..8d7a0fbb1046 100644
>> --- a/include/hw/vfio/vfio-common.h
>> +++ b/include/hw/vfio/vfio-common.h
>> @@ -171,6 +171,7 @@ int vfio_region_setup(Object *obj, VFIODevice 
>> *vbasedev, VFIORegion *region,
>>                         int index, const char *name);
>>   int vfio_region_mmap(VFIORegion *region);
>>   void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled);
>> +void vfio_region_unmap(VFIORegion *region);
>>   void vfio_region_exit(VFIORegion *region);
>>   void vfio_region_finalize(VFIORegion *region);
>>   void vfio_reset_handler(void *opaque);
>>
>