Re: [PATCH v1 14/17] intel_iommu: piotlb invalidation should notify unmap

[CLEMENT MATHIEU--DRIF <clement.mathieu--drif@eviden.com>]

On 24/07/2024 07:45, CLEMENT MATHIEU--DRIF wrote:
> Maybe I'm missing something but why do we invalidate device IOTLB
> upon piotlb receipt of a regular IOTLB inv desc?
> I don't get why we don't wait for a device IOTLB inv desc?
I thought you were planning to remove that after the last rfc version
>
> On 18/07/2024 10:16, Zhenzhong Duan wrote:
>> Caution: External email. Do not open attachments or click links, unless this email comes from a known sender and you know the content is safe.
>>
>>
>> This is used by some emulated devices which caches address
>> translation result. When piotlb invalidation issued in guest,
>> those caches should be refreshed.
>>
>> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>>    hw/i386/intel_iommu.c | 35 ++++++++++++++++++++++++++++++++++-
>>    1 file changed, 34 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>> index 8b66d6cfa5..c0116497b1 100644
>> --- a/hw/i386/intel_iommu.c
>> +++ b/hw/i386/intel_iommu.c
>> @@ -2910,7 +2910,7 @@ static void vtd_piotlb_pasid_invalidate(IntelIOMMUState *s,
>>                    continue;
>>                }
>>
>> -            if (!s->scalable_modern) {
>> +            if (!s->scalable_modern || !vtd_as_has_map_notifier(vtd_as)) {
>>                    vtd_address_space_sync(vtd_as);
>>                }
>>            }
>> @@ -2922,6 +2922,9 @@ static void vtd_piotlb_page_invalidate(IntelIOMMUState *s, uint16_t domain_id,
>>                                           bool ih)
>>    {
>>        VTDIOTLBPageInvInfo info;
>> +    VTDAddressSpace *vtd_as;
>> +    VTDContextEntry ce;
>> +    hwaddr size = (1 << am) * VTD_PAGE_SIZE;
>>
>>        info.domain_id = domain_id;
>>        info.pasid = pasid;
>> @@ -2932,6 +2935,36 @@ static void vtd_piotlb_page_invalidate(IntelIOMMUState *s, uint16_t domain_id,
>>        g_hash_table_foreach_remove(s->iotlb,
>>                                    vtd_hash_remove_by_page_piotlb, &info);
>>        vtd_iommu_unlock(s);
>> +
>> +    QLIST_FOREACH(vtd_as, &s->vtd_as_with_notifiers, next) {
>> +        if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
>> +                                      vtd_as->devfn, &ce) &&
>> +            domain_id == vtd_get_domain_id(s, &ce, vtd_as->pasid)) {
>> +            uint32_t rid2pasid = VTD_CE_GET_RID2PASID(&ce);
>> +            IOMMUTLBEvent event;
>> +
>> +            if ((vtd_as->pasid != PCI_NO_PASID || pasid != rid2pasid) &&
>> +                vtd_as->pasid != pasid) {
>> +                continue;
>> +            }
>> +
>> +            /*
>> +             * Page-Selective-within-PASID PASID-based-IOTLB Invalidation
>> +             * does not flush stage-2 entries. See spec section 6.5.2.4
>> +             */
>> +            if (!s->scalable_modern) {
>> +                continue;
>> +            }
>> +
>> +            event.type = IOMMU_NOTIFIER_UNMAP;
>> +            event.entry.target_as = &address_space_memory;
>> +            event.entry.iova = addr;
>> +            event.entry.perm = IOMMU_NONE;
>> +            event.entry.addr_mask = size - 1;
>> +            event.entry.translated_addr = 0;
>> +            memory_region_notify_iommu(&vtd_as->iommu, 0, event);
>> +        }
>> +    }
>>    }
>>
>>    static bool vtd_process_piotlb_desc(IntelIOMMUState *s,
>> --
>> 2.34.1
>>