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

Jacob Pan
2019-04-30T17:12:40Z

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);

> 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]