Re: [PATCH v4 21/22] iommu/vt-d: Support flushing more translation cache types

[Auger Eric <eric.auger@redhat.com>]

Hi Jacob,

On 6/9/19 3:44 PM, Jacob Pan wrote:
> When Shared Virtual Memory is exposed to a guest via vIOMMU, scalable
> 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        | 50 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/intel-iommu.h | 21 +++++++++++++++----
>  2 files changed, 67 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
> index 6d969a1..0cda6fb 100644
> --- a/drivers/iommu/dmar.c
> +++ b/drivers/iommu/dmar.c
> @@ -1357,6 +1357,21 @@ 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, int ih)
> +{
> +	struct qi_desc desc;
nit: you could also init to {};
> +
> +	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(ih) |
> +		QI_EIOTLB_AM(size_order);
> +	desc.qw2 = 0;
> +	desc.qw3 = 0;
> +	qi_submit_sync(&desc, iommu);
> +}
> +
>  void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
>  			u16 qdep, u64 addr, unsigned mask)
>  {
> @@ -1380,6 +1395,41 @@ void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
>  	qi_submit_sync(&desc, iommu);
>  }
>  
> +/* PASID-based device IOTLB Invalidate */
> +void qi_flush_dev_piotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
> +		u32 pasid,  u16 qdep, u64 addr, unsigned size, u64 granu)
s/size/size_order
> +{
> +	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);
maybe add a comment to remind MIP hint is sent to 0 as of now.
> +	desc.qw1 = QI_DEV_EIOTLB_GLOB(granu);
> +
> +	/* 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;
this is qw1.
> +	else {
> +		unsigned long mask = 1UL << (VTD_PAGE_SHIFT + size);
don't you miss a "- 1 " here?
> +
> +		desc.qw1 |= QI_DEV_EIOTLB_ADDR(addr & ~mask) | QI_DEV_EIOTLB_SIZE;
desc.qw1 |= addr & ~mask | QI_DEV_EIOTLB_SIZE;
ie. I don't think QI_DEV_EIOTLB_ADDR is useful here?


So won't the following lines do the job?

unsigned long mask = 1UL << (VTD_PAGE_SHIFT + size) -1;
desc.qw1 |= addr & ~mask;
if (size)
    desc.qw1 |= QI_DEV_EIOTLB_SIZE
> +	}
> +	qi_submit_sync(&desc, iommu);
> +}
> +
> +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);
nit: reorder the fields according to the spec, easier to check if any is
missing.
> +	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 94d3a9a..1cdb35b 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, int ih);
>  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);
s/size/size_order
> +
> +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
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