Re: [PATCH v8 09/10] iommufd: Add data structure for Intel VT-d stage-1 cache invalidation

Yi Liu
2023-12-28T08:32:24Z

On 2023/12/28 14:38, Tian, Kevin wrote:
>> From: Tian, Kevin
>> Sent: Thursday, December 28, 2023 2:38 PM
>>
>>> From: Liu, Yi L <yi.l.liu@intel.com>
>>> Sent: Thursday, December 28, 2023 12:14 AM
>>> +/**
>>> + * struct iommu_hwpt_vtd_s1_invalidate - Intel VT-d cache invalidation
>>> + * (IOMMU_HWPT_INVALIDATE_DATA_VTD_S1)
>>> + * @addr: The start address of the range to be invalidated. It needs to
>>> + * be 4KB aligned.
>>> + * @npages: Number of contiguous 4K pages to be invalidated.
>>> + * @flags: Combination of enum iommu_hwpt_vtd_s1_invalidate_flags
>>> + * @hw_error: One of enum iommu_hwpt_vtd_s1_invalidate_error
>>> + *
>>> + * The Intel VT-d specific invalidation data for user-managed stage-1 cache
>>> + * invalidation in nested translation. Userspace uses this structure to
>>> + * tell the impacted cache scope after modifying the stage-1 page table.
>>> + *
>>> + * Invalidating all the caches related to the page table by setting @addr
>>> + * to be 0 and @npages to be U64_MAX.
>>> + *
>>> + * The device TLB will be invalidated automatically if ATS is enabled.
>>> + *
>>> + * The @hw_error is meaningful when the entry is handled by the kernel.
>>> + * Check the entry_num output of IOMMU_HWPT_INVALIDATE ioctl to
>>> know the
>>> + * handled entries. @hw_error only covers the errors detected by
>> hardware.
>>> + * The software detected errors would go through the normal ioctl errno.
>>> + */
>>
>> * An entry is considered 'handled' after it passes the audit and submitted
>> * to the IOMMU by the underlying driver. Check the @entry_num output of
>> * struct iommu_hwpt_invalidate for the number of handled entries. A
>> 'handled'
>> * request may still fail in hardware for various reasons, e.g. due to timeout
>> * on waiting for device response upon a device TLB invalidation request. In
>> * such case the hardware error info is reported in the @hw_error field of the
>> * handled entry.
>
> with that:
>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

yep.

--
Regards,
Yi Liu