Re: [PATCH v2 18/19] iommu/vt-d: Support flushing more translation cache types

Auger Eric
2019-04-30T17:41:33Z

Hi Jacob,

On 4/30/19 7:15 PM, Jacob Pan wrote:
> On Tue, 30 Apr 2019 06:41:13 +0200
> Auger Eric <eric.auger@redhat.com> wrote:
>
>> Hi Jacob,
>>
>> On 4/29/19 11:29 PM, Jacob Pan wrote:
>>> On Sat, 27 Apr 2019 11:04:04 +0200
>>> Auger Eric <eric.auger@redhat.com> wrote:
>>>
>>>> Hi Jacob,
>>>>
>>>> On 4/24/19 1:31 AM, Jacob Pan wrote:
>>>>> When Shared Virtual Memory is exposed to a guest via vIOMMU,
>>>>> extended IOTLB invalidation may be passed down from outside IOMMU
>>>>> subsystems. This patch adds invalidation functions that can be
>>>>> used for additional translation cache types.
>>>>>
>>>>> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
>>>>> ---
>>>>> drivers/iommu/dmar.c | 48
>>>>> +++++++++++++++++++++++++++++++++++++++++++++
>>>>> include/linux/intel-iommu.h | 21 ++++++++++++++++---- 2 files
>>>>> changed, 65 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
>>>>> index 9c49300..680894e 100644
>>>>> --- a/drivers/iommu/dmar.c
>>>>> +++ b/drivers/iommu/dmar.c
>>>>> @@ -1357,6 +1357,20 @@ void qi_flush_iotlb(struct intel_iommu
>>>>> *iommu, u16 did, u64 addr, qi_submit_sync(&desc, iommu);
>>>>> }
>>>>>
>>>> /* PASID-based IOTLB Invalidate */
>>>>> +void qi_flush_piotlb(struct intel_iommu *iommu, u16 did, u64
>>>>> addr, u32 pasid,
>>>>> + unsigned int size_order, u64 granu)
>>>>> +{
>>>>> + struct qi_desc desc;
>>>>> +
>>>>> + desc.qw0 = QI_EIOTLB_PASID(pasid) | QI_EIOTLB_DID(did) |
>>>>> + QI_EIOTLB_GRAN(granu) | QI_EIOTLB_TYPE;
>>>>> + desc.qw1 = QI_EIOTLB_ADDR(addr) | QI_EIOTLB_IH(0) |
>>>>> + QI_EIOTLB_AM(size_order);
>>>> I see IH it hardcoded to 0. Don't you envision to cascade the IH.
>>>> On ARM this was needed for perf sake.
>>> Right, we should cascade IH based on IOMMU_INV_ADDR_FLAGS_LEAF. Just
>>> curious how do you deduce the IH information on ARM? I guess you
>>> need to get the non-leaf page directory info?
>>> I will add an argument for IH.
>> On ARM we have the "Leaf" field in the stage1 TLB invalidation
>> command. "When Leaf==1, only cached entries for the last level of
>> translation table walk are required to be invalidated".
>>
> Thanks for explaining, I guess I didn't ask the right question. I was
> wondering how SMMU driver determines when to set the Leaf bit. I guess
> it is this function? It is not apparent to me whether the sharing of
> non-leaf TLBs are considered.
> io_pgtable_tlb_add_flush(iop, iova, blk_size, blk_size, true);

the leaf value is passed as arg to
tlb_sync cb = arm_smmu_tlb_inv_range_nosync so the actual decision is
made in io-pgtable-arm.c, see io_pgtable_tlb_sync call sites.

Thanks

Eric
>
>> Thanks
>>
>> Eric
>> [...]
>>>> /* Pasid-based Device-TLB Invalidation */
>> [...]
>>>>> +void qi_flush_dev_piotlb(struct intel_iommu *iommu, u16 sid, u16
>>>>> pfsid,
>>>>> + u32 pasid, u16 qdep, u64 addr, unsigned size,
>>>>> u64 granu) +{
>>>>> + struct qi_desc desc;
>>>>> +
>>>>> + desc.qw0 = QI_DEV_EIOTLB_PASID(pasid) |
>>>>> QI_DEV_EIOTLB_SID(sid) |
>>>>> + QI_DEV_EIOTLB_QDEP(qdep) | QI_DEIOTLB_TYPE |
>>>>> + QI_DEV_IOTLB_PFSID(pfsid);
>>>>> + desc.qw1 |= QI_DEV_EIOTLB_GLOB(granu);
>>> should be desc.qw1 =
>>>>> +
>>>>> + /* If S bit is 0, we only flush a single page. If S bit
>>>>> is set,
>>>>> + * The least significant zero bit indicates the size.
>>>>> VT-d spec
>>>>> + * 6.5.2.6
>>>>> + */
>>>>> + if (!size)
>>>>> + desc.qw0 = QI_DEV_EIOTLB_ADDR(addr) &
>>>>> ~QI_DEV_EIOTLB_SIZE;
>>>> desc.q1 |= ?
>>> Right, I also missed previous qw1 assignment.
>>>>> + else {
>>>>> + unsigned long mask = 1UL << (VTD_PAGE_SHIFT +
>>>>> size); +
>>>>> + desc.qw1 = QI_DEV_EIOTLB_ADDR(addr & ~mask) |
>>>>> QI_DEV_EIOTLB_SIZE;
>>>> desc.q1 |=
>>> right, thanks
>>>>> + }
>>>>> + qi_submit_sync(&desc, iommu);
>>>>> +}
>>>>> +
>>>> /* PASID-cache invalidation */
>>>>> +void qi_flush_pasid_cache(struct intel_iommu *iommu, u16 did, u64
>>>>> granu, int pasid) +{
>>>>> + struct qi_desc desc;
>>>>> +
>>>>> + desc.qw0 = QI_PC_TYPE | QI_PC_DID(did) |
>>>>> QI_PC_GRAN(granu) | QI_PC_PASID(pasid);
>>>>> + desc.qw1 = 0;
>>>>> + desc.qw2 = 0;
>>>>> + desc.qw3 = 0;
>>>>> + qi_submit_sync(&desc, iommu);
>>>>> +}
>>>>> /*
>>>>> * Disable Queued Invalidation interface.
>>>>> */
>>>>> diff --git a/include/linux/intel-iommu.h
>>>>> b/include/linux/intel-iommu.h index 5d67d0d4..38e5efb 100644
>>>>> --- a/include/linux/intel-iommu.h
>>>>> +++ b/include/linux/intel-iommu.h
>>>>> @@ -339,7 +339,7 @@ enum {
>>>>> #define QI_IOTLB_GRAN(gran) (((u64)gran) >>
>>>>> (DMA_TLB_FLUSH_GRANU_OFFSET-4)) #define QI_IOTLB_ADDR(addr)
>>>>> (((u64)addr) & VTD_PAGE_MASK) #define
>>>>> QI_IOTLB_IH(ih) (((u64)ih) << 6) -#define
>>>>> QI_IOTLB_AM(am) (((u8)am)) +#define
>>>>> QI_IOTLB_AM(am) (((u8)am) & 0x3f)
>>>>> #define QI_CC_FM(fm) (((u64)fm) << 48)
>>>>> #define QI_CC_SID(sid) (((u64)sid) << 32)
>>>>> @@ -357,17 +357,22 @@ enum {
>>>>> #define QI_PC_DID(did) (((u64)did) << 16)
>>>>> #define QI_PC_GRAN(gran) (((u64)gran) << 4)
>>>>>
>>>>> -#define QI_PC_ALL_PASIDS (QI_PC_TYPE | QI_PC_GRAN(0))
>>>>> -#define QI_PC_PASID_SEL (QI_PC_TYPE |
>>>>> QI_PC_GRAN(1)) +/* PASID cache invalidation granu */
>>>>> +#define QI_PC_ALL_PASIDS 0
>>>>> +#define QI_PC_PASID_SEL 1
>>>>>
>>>>> #define QI_EIOTLB_ADDR(addr) ((u64)(addr) & VTD_PAGE_MASK)
>>>>> #define QI_EIOTLB_GL(gl) (((u64)gl) << 7)
>>>>> #define QI_EIOTLB_IH(ih) (((u64)ih) << 6)
>>>>> -#define QI_EIOTLB_AM(am) (((u64)am))
>>>>> +#define QI_EIOTLB_AM(am) (((u64)am) & 0x3f)
>>>>> #define QI_EIOTLB_PASID(pasid) (((u64)pasid) << 32)
>>>>> #define QI_EIOTLB_DID(did) (((u64)did) << 16)
>>>>> #define QI_EIOTLB_GRAN(gran) (((u64)gran) << 4)
>>>>>
>>>>> +/* QI Dev-IOTLB inv granu */
>>>>> +#define QI_DEV_IOTLB_GRAN_ALL 1
>>>>> +#define QI_DEV_IOTLB_GRAN_PASID_SEL 0
>>>>> +
>>>>> #define QI_DEV_EIOTLB_ADDR(a) ((u64)(a) & VTD_PAGE_MASK)
>>>>> #define QI_DEV_EIOTLB_SIZE (((u64)1) << 11)
>>>>> #define QI_DEV_EIOTLB_GLOB(g) ((u64)g)
>>>>> @@ -658,8 +663,16 @@ extern void qi_flush_context(struct
>>>>> intel_iommu *iommu, u16 did, u16 sid, u8 fm, u64 type);
>>>>> extern void qi_flush_iotlb(struct intel_iommu *iommu, u16 did,
>>>>> u64 addr, unsigned int size_order, u64 type);
>>>>> +extern void qi_flush_piotlb(struct intel_iommu *iommu, u16 did,
>>>>> u64 addr,
>>>>> + u32 pasid, unsigned int size_order, u64
>>>>> type); extern void qi_flush_dev_iotlb(struct intel_iommu *iommu,
>>>>> u16 sid, u16 pfsid, u16 qdep, u64 addr, unsigned mask);
>>>>> +
>>>>> +extern void qi_flush_dev_piotlb(struct intel_iommu *iommu, u16
>>>>> sid, u16 pfsid,
>>>>> + u32 pasid, u16 qdep, u64 addr, unsigned
>>>>> size, u64 granu); +
>>>>> +extern void qi_flush_pasid_cache(struct intel_iommu *iommu, u16
>>>>> did, u64 granu, int pasid); +
>>>>> extern int qi_submit_sync(struct qi_desc *desc, struct
>>>>> intel_iommu *iommu);
>>>>> extern int dmar_ir_support(void);
>>>>>
>>>>
>>>> Thanks
>>>>
>>>> Eric
>>>
>>> [Jacob Pan]
>>>
>
> [Jacob Pan]
>