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

[Liu, Yi L]

> On Dec 22, 2023, at 11:56, Yang, Weijiang <weijiang.yang@xxxxxxxxx> wrote:
> 
> On 12/21/2023 11:39 PM, Yi Liu wrote:
>> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>> 
>> This implements the .cache_invalidate_user() callback to support iotlb
>> flush for nested domain.
>> 
>> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>> Co-developed-by: Yi Liu <yi.l.liu@xxxxxxxxx>
>> Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
>> ---
>>  drivers/iommu/intel/nested.c | 116 +++++++++++++++++++++++++++++++++++
>>  1 file changed, 116 insertions(+)
>> 
>> diff --git a/drivers/iommu/intel/nested.c b/drivers/iommu/intel/nested.c
>> index b5a5563ab32c..c665e2647045 100644
>> --- a/drivers/iommu/intel/nested.c
>> +++ b/drivers/iommu/intel/nested.c
>> @@ -73,9 +73,125 @@ static void intel_nested_domain_free(struct iommu_domain *domain)
>>      kfree(to_dmar_domain(domain));
>>  }
>>  +static void nested_flush_pasid_iotlb(struct intel_iommu *iommu,
>> +                     struct dmar_domain *domain, u64 addr,
>> +                     unsigned long npages, bool ih)
>> +{
>> +    u16 did = domain_id_iommu(domain, iommu);
>> +    unsigned long flags;
>> +
>> +    spin_lock_irqsave(&domain->lock, flags);
>> +    if (!list_empty(&domain->devices))
>> +        qi_flush_piotlb(iommu, did, IOMMU_NO_PASID, addr,
>> +                npages, ih, NULL);
>> +    spin_unlock_irqrestore(&domain->lock, flags);
>> +}
>> +
>> +static void nested_flush_dev_iotlb(struct dmar_domain *domain, u64 addr,
>> +                   unsigned mask, u32 *fault)
>> +{
>> +    struct device_domain_info *info;
>> +    unsigned long flags;
>> +    u16 sid, qdep;
>> +
>> +    spin_lock_irqsave(&domain->lock, flags);
>> +    list_for_each_entry(info, &domain->devices, link) {
>> +        if (!info->ats_enabled)
>> +            continue;
>> +        sid = info->bus << 8 | info->devfn;
>> +        qdep = info->ats_qdep;
>> +        qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
>> +                   qdep, addr, mask, fault);
>> +        quirk_extra_dev_tlb_flush(info, addr, mask,
>> +                      IOMMU_NO_PASID, qdep);
>> +    }
>> +    spin_unlock_irqrestore(&domain->lock, flags);
>> +}
>> +
>> +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);
>> +
>> +        if (domain->has_iotlb_device)
>> +            continue;
> 
> Shouldn't this be if (!domain->has_iotlb_device)?

oops, yes it is.

>> +
>> +        nested_flush_dev_iotlb(domain, addr, mask, &fault);
>> +        if (fault & (DMA_FSTS_ITE | DMA_FSTS_ICE))
>> +            break;
>> +    }
>> +
>> +    if (fault & DMA_FSTS_ICE)
>> +        *error |= IOMMU_HWPT_INVALIDATE_VTD_S1_ICE;
>> +    if (fault & DMA_FSTS_ITE)
>> +        *error |= IOMMU_HWPT_INVALIDATE_VTD_S1_ITE;
>> +}
>> +
>> +static int intel_nested_cache_invalidate_user(struct iommu_domain *domain,
>> +                          struct iommu_user_data_array *array)
>> +{
>> +    struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>> +    struct iommu_hwpt_vtd_s1_invalidate inv_entry;
>> +    u32 processed = 0;
>> +    int ret = 0;
>> +    u32 index;
>> +
>> +    if (array->type != IOMMU_HWPT_INVALIDATE_DATA_VTD_S1) {
>> +        ret = -EINVAL;
>> +        goto out;
>> +    }
>> +
>> +    for (index = 0; index < array->entry_num; index++) {
>> +        ret = iommu_copy_struct_from_user_array(&inv_entry, array,
>> +                            IOMMU_HWPT_INVALIDATE_DATA_VTD_S1,
>> +                            index, inv_error);
>> +        if (ret)
>> +            break;
>> +
>> +        if (inv_entry.flags & ~IOMMU_VTD_INV_FLAGS_LEAF) {
>> +            ret = -EOPNOTSUPP;
>> +            break;
>> +        }
>> +
>> +        if (!IS_ALIGNED(inv_entry.addr, VTD_PAGE_SIZE) ||
>> +            ((inv_entry.npages == U64_MAX) && inv_entry.addr)) {
>> +            ret = -EINVAL;
>> +            break;
>> +        }
>> +
>> +        inv_entry.inv_error = 0;
>> +        intel_nested_flush_cache(dmar_domain, inv_entry.addr,
>> +                     inv_entry.npages, &inv_entry.inv_error);
>> +
>> +        ret = iommu_respond_struct_to_user_array(array, index,
>> +                             (void *)&inv_entry,
>> +                             sizeof(inv_entry));
>> +        if (ret)
>> +            break;
>> +
>> +        processed++;
>> +    }
>> +
>> +out:
>> +    array->entry_num = processed;
>> +    return ret;
>> +}
>> +
>>  static const struct iommu_domain_ops intel_nested_domain_ops = {
>>      .attach_dev        = intel_nested_attach_dev,
>>      .free            = intel_nested_domain_free,
>> +    .cache_invalidate_user    = intel_nested_cache_invalidate_user,
>>  };
>>    struct iommu_domain *intel_nested_domain_alloc(struct iommu_domain *parent,
>