[PATCH v3 11/23] iommufd/viommu: Add IOMMUFD_CMD_VQUEUE_ALLOC ioctl

[Vasant Hegde]

Jason,

On 5/7/2025 6:01 PM, Jason Gunthorpe wrote:
> On Wed, May 07, 2025 at 01:11:43PM +0530, Vasant Hegde wrote:
>>   -  MMIO Offset 0018h IOMMU Control Register
>>      EventLogEn: Event log enable
>>        * When guest sets this bit, qemu will trap and will send queue_alloc
>>        * When guest disables this bit, qemu will trap and send vqueue_destroy
>>
>>      This part is fine.
> 
> Ok
> 
>>      EventIntEn: Event log interrupt enable
>>        * When guest sets this bit, qemu will trap
>>        * this needs to be communicated to Host so that we can program VF Control
>> BAR and enable the interrupt
> 
> This sounds like modifying the vqueue? Or maybe on the viommu?

IMO its VIOMMU as it informs HW to trigger interrupt or not.


> 
>>   - There is other bit "Completion wait interrupt enable"
>>     This doesn't related to any buffer. Instead if we configure this for
>> completion wait command it will generate interrupt.
> 
> This sounds like a modify on the VIOMMU object?

Again in my view its VIOMMU object as it tells HW what to do when it finishes
completion wait command.

-Vasant