Re: [Qemu-devel] [RFC PATCH v2 10/13] linux headers update for DDW

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/19/2014 03:42 AM, Alex Williamson wrote:
> On Fri, 2014-08-15 at 20:12 +1000, Alexey Kardashevskiy wrote:
>> Since the changes are not in upstream yet, no tag or branch is specified here.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>  linux-headers/linux/vfio.h | 37 ++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 36 insertions(+), 1 deletion(-)
>>
>> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
>> index 26c218e..f0aa97d 100644
>> --- a/linux-headers/linux/vfio.h
>> +++ b/linux-headers/linux/vfio.h
>> @@ -448,13 +448,48 @@ struct vfio_iommu_type1_dma_unmap {
>>   */
>>  struct vfio_iommu_spapr_tce_info {
>>  	__u32 argsz;
>> -	__u32 flags;			/* reserved for future use */
>> +	__u32 flags;
>> +#define VFIO_IOMMU_SPAPR_TCE_FLAG_DDW	1 /* Support dynamic windows */
>>  	__u32 dma32_window_start;	/* 32 bit window start (bytes) */
>>  	__u32 dma32_window_size;	/* 32 bit window size (bytes) */
>>  };
>>  
>>  #define VFIO_IOMMU_SPAPR_TCE_GET_INFO	_IO(VFIO_TYPE, VFIO_BASE + 12)
>>  
>> +/*
>> + * Dynamic DMA windows
>> + */
>> +struct vfio_iommu_spapr_tce_query {
>> +	__u32 argsz;
>> +	/* out */
>> +	__u32 windows_available;
>> +	__u32 page_size_mask;
>> +};
> 
> Why do we need a new ioctl for this vs extending tce_info to include it?
> That's sort of the point of including argsz and flags in the ioctl.


It is not actual now but I can imagine that these numbers may change
depending on multiple calls of create()/remove().


> 
>> +#define VFIO_IOMMU_SPAPR_TCE_QUERY	_IO(VFIO_TYPE, VFIO_BASE + 17)
>> +
>> +struct vfio_iommu_spapr_tce_create {
>> +	__u32 argsz;
>> +	/* in */
>> +	__u32 page_shift;
>> +	__u32 window_shift;
>> +	/* out */
>> +	__u64 start_addr;
>> +
>> +};
>> +#define VFIO_IOMMU_SPAPR_TCE_CREATE	_IO(VFIO_TYPE, VFIO_BASE + 18)
>> +
>> +struct vfio_iommu_spapr_tce_remove {
>> +	__u32 argsz;
>> +	/* in */
>> +	__u64 start_addr;
>> +};
>> +#define VFIO_IOMMU_SPAPR_TCE_REMOVE	_IO(VFIO_TYPE, VFIO_BASE + 19)
>> +
>> +struct vfio_iommu_spapr_tce_reset {
>> +	__u32 argsz;
>> +};
>> +#define VFIO_IOMMU_SPAPR_TCE_RESET	_IO(VFIO_TYPE, VFIO_BASE + 20)
>> +
> 
> argsz by itself seems rather pointless if we don't have a flags field to
> augment the structure.  Thanks,


Add flags and check for zero  or  remove it? Cannot choose, please help :)


> Alex
> 
>>  /* ***************************************************************** */
>>  
>>  #endif /* VFIO_H */
> 
> 
> 


-- 
Alexey