Re: [PATCH v7 9/9] iommu/vt-d: Add iotlb flush for nested domain

Yi Liu
2023-12-26T12:32:46Z

On 2023/12/26 12:51, Yi Liu wrote:
> On 2023/12/22 14:57, Tian, Kevin wrote:
>>> From: Liu, Yi L <yi.l.liu@intel.com>
>>> Sent: Thursday, December 21, 2023 11:40 PM
>>>
>>> +
>>> +static void intel_nested_flush_cache(struct dmar_domain *domain, u64
>>> addr,
>>> +                     unsigned long npages, u32 *error)
>>> +{
>>> +    struct iommu_domain_info *info;
>>> +    unsigned long i;
>>> +    unsigned mask;
>>> +    u32 fault = 0;
>>> +
>>> +    if (npages == U64_MAX)
>>> +        mask = 64 - VTD_PAGE_SHIFT;
>>> +    else
>>> +        mask = ilog2(__roundup_pow_of_two(npages));
>>> +
>>> +    xa_for_each(&domain->iommu_array, i, info) {
>>> +        nested_flush_pasid_iotlb(info->iommu, domain, addr,
>>> npages, 0);
>>
>> so IOMMU_VTD_INV_FLAGS_LEAF is defined but ignored?
>
> yeah... it is. It is named as ih in the driver code. But it appears only
> the below code is set ih. When calling iommu_flush_iotlb_psi(), the 5th
> parameter (ih) may be true.
>
> static int intel_iommu_memory_notifier(struct notifier_block *nb,
>                        unsigned long val, void *v)
> {
>     struct memory_notify *mhp = v;
>     unsigned long start_vpfn = mm_to_dma_pfn(mhp->start_pfn);
>     unsigned long last_vpfn = mm_to_dma_pfn(mhp->start_pfn +
>             mhp->nr_pages - 1);
>
>     switch (val) {
>     case MEM_GOING_ONLINE:
>         if (iommu_domain_identity_map(si_domain,
>                           start_vpfn, last_vpfn)) {
>             pr_warn("Failed to build identity map for [%lx-%lx]\n",
>                 start_vpfn, last_vpfn);
>             return NOTIFY_BAD;
>         }
>         break;
>
>     case MEM_OFFLINE:
>     case MEM_CANCEL_ONLINE:
>         {
>             struct dmar_drhd_unit *drhd;
>             struct intel_iommu *iommu;
>             LIST_HEAD(freelist);
>
>             domain_unmap(si_domain, start_vpfn, last_vpfn, &freelist);
>
>             rcu_read_lock();
>             for_each_active_iommu(iommu, drhd)
>                 iommu_flush_iotlb_psi(iommu, si_domain,
>                     start_vpfn, mhp->nr_pages,
>                     list_empty(&freelist), 0);
>             rcu_read_unlock();
>             put_pages_list(&freelist);
>         }
>         break;
>     }
>
>     return NOTIFY_OK;
> }

I passed this flag to the intel_nested_flush_cache() now as the
helper accepts an ih parameter.

--
Regards,
Yi Liu