| Message ID | 20210212105859.8445-2-vivek.gautam@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Domain nesting info for arm-smmu | expand |
Hi Vivek, On 2/12/21 11:58 AM, Vivek Gautam wrote: > Add a vendor specific structure for domain nesting info for > arm smmu-v3, and necessary info fields required to populate > stage1 page tables. > > Signed-off-by: Vivek Gautam <vivek.gautam@arm.com> > --- > include/uapi/linux/iommu.h | 31 +++++++++++++++++++++++++------ > 1 file changed, 25 insertions(+), 6 deletions(-) > > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > index 4d3d988fa353..5f059bcf7720 100644 > --- a/include/uapi/linux/iommu.h > +++ b/include/uapi/linux/iommu.h > @@ -323,7 +323,8 @@ struct iommu_gpasid_bind_data { > #define IOMMU_GPASID_BIND_VERSION_1 1 > __u32 version; > #define IOMMU_PASID_FORMAT_INTEL_VTD 1 > -#define IOMMU_PASID_FORMAT_LAST 2 > +#define IOMMU_PASID_FORMAT_ARM_SMMU_V3 2 > +#define IOMMU_PASID_FORMAT_LAST 3 > __u32 format; > __u32 addr_width; > #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid */ > @@ -409,6 +410,21 @@ struct iommu_nesting_info_vtd { > __u64 ecap_reg; > }; > > +/* > + * struct iommu_nesting_info_arm_smmuv3 - Arm SMMU-v3 nesting info. > + */ > +struct iommu_nesting_info_arm_smmuv3 { > + __u32 flags; > + __u16 asid_bits; > + > + /* Arm LPAE page table format as per kernel */ > +#define ARM_PGTBL_32_LPAE_S1 (0x0) > +#define ARM_PGTBL_64_LPAE_S1 (0x2) Shouldn't it be a bitfield instead as both can be supported (the actual driver only supports 64b table format though). Does it match matches IDR0.TTF? > + __u8 pgtbl_fmt; So I understand this API is supposed to allow VFIO to expose those info early enough to the userspace to help configuring the viommu and avoid errors later on. I wonder how far we want to go on this path. What about those other caps that impact the STE/CD validity. There may be others... SMMU_IDR0.CD2L (support of 2 stage CD) SMMU_IDR0.TTENDIAN (endianness) SMMU_IDR0.HTTU (if 0 forbids HA/HD setting in the CD) SMMU_IDR3.STT (impacts T0SZ) Thanks Eric > + > + __u8 padding[9]; > +}; > + > /* > * struct iommu_nesting_info - Information for nesting-capable IOMMU. > * userspace should check it before using > @@ -445,11 +461,13 @@ struct iommu_nesting_info_vtd { > * +---------------+------------------------------------------------------+ > * > * data struct types defined for @format: > - * +================================+=====================================+ > - * | @format | data struct | > - * +================================+=====================================+ > - * | IOMMU_PASID_FORMAT_INTEL_VTD | struct iommu_nesting_info_vtd | > - * +--------------------------------+-------------------------------------+ > + * +================================+======================================+ > + * | @format | data struct | > + * +================================+======================================+ > + * | IOMMU_PASID_FORMAT_INTEL_VTD | struct iommu_nesting_info_vtd | > + * +---------------+-------------------------------------------------------+ > + * | IOMMU_PASID_FORMAT_ARM_SMMU_V3 | struct iommu_nesting_info_arm_smmuv3 | > + * +--------------------------------+--------------------------------------+ > * > */ > struct iommu_nesting_info { > @@ -466,6 +484,7 @@ struct iommu_nesting_info { > /* Vendor specific data */ > union { > struct iommu_nesting_info_vtd vtd; > + struct iommu_nesting_info_arm_smmuv3 smmuv3; > } vendor; > }; > >
Hi Eric, On 2/12/21 11:43 PM, Auger Eric wrote: > Hi Vivek, > On 2/12/21 11:58 AM, Vivek Gautam wrote: >> Add a vendor specific structure for domain nesting info for >> arm smmu-v3, and necessary info fields required to populate >> stage1 page tables. >> >> Signed-off-by: Vivek Gautam <vivek.gautam@arm.com> >> --- >> include/uapi/linux/iommu.h | 31 +++++++++++++++++++++++++------ >> 1 file changed, 25 insertions(+), 6 deletions(-) >> >> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >> index 4d3d988fa353..5f059bcf7720 100644 >> --- a/include/uapi/linux/iommu.h >> +++ b/include/uapi/linux/iommu.h >> @@ -323,7 +323,8 @@ struct iommu_gpasid_bind_data { >> #define IOMMU_GPASID_BIND_VERSION_1 1 >> __u32 version; >> #define IOMMU_PASID_FORMAT_INTEL_VTD 1 >> -#define IOMMU_PASID_FORMAT_LAST 2 >> +#define IOMMU_PASID_FORMAT_ARM_SMMU_V3 2 >> +#define IOMMU_PASID_FORMAT_LAST 3 >> __u32 format; >> __u32 addr_width; >> #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid */ >> @@ -409,6 +410,21 @@ struct iommu_nesting_info_vtd { >> __u64 ecap_reg; >> }; >> >> +/* >> + * struct iommu_nesting_info_arm_smmuv3 - Arm SMMU-v3 nesting info. >> + */ >> +struct iommu_nesting_info_arm_smmuv3 { >> + __u32 flags; >> + __u16 asid_bits; >> + >> + /* Arm LPAE page table format as per kernel */ >> +#define ARM_PGTBL_32_LPAE_S1 (0x0) >> +#define ARM_PGTBL_64_LPAE_S1 (0x2) Thanks for reviewing and I am terribly sorry for coming to it with delay. > Shouldn't it be a bitfield instead as both can be supported (the actual > driver only supports 64b table format though). Does it match matches > IDR0.TTF? Yes, it should be a bitfield rather, and it doesn't match with IDR0.TTF. This is to hint the stage1 table allocations from viommu. Please see viommu_setup_pgtable() in the patch at [1]. >> + __u8 pgtbl_fmt; > So I understand this API is supposed to allow VFIO to expose those info > early enough to the userspace to help configuring the viommu and avoid > errors later on. I wonder how far we want to go on this path. What about > those other caps that impact the STE/CD validity. There may be others... > > SMMU_IDR0.CD2L (support of 2 stage CD) > SMMU_IDR0.TTENDIAN (endianness) > SMMU_IDR0.HTTU (if 0 forbids HA/HD setting in the CD) > SMMU_IDR3.STT (impacts T0SZ) Right. The idea was to start with a minimal set of configuration. But as you rightly pointed out we need a scalable solution to this problem for arm-smmu-v3. I am now thinking if we could even use the nesting_info for arm. We don't want to end up adding flags for all the feature bits. Let me know if you have any suggestions. Best regards Vivek [1] https://lore.kernel.org/linux-arm-kernel/20210115121342.15093-14-vivek.gautam@arm.com/ [snip]
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h index 4d3d988fa353..5f059bcf7720 100644 --- a/include/uapi/linux/iommu.h +++ b/include/uapi/linux/iommu.h @@ -323,7 +323,8 @@ struct iommu_gpasid_bind_data { #define IOMMU_GPASID_BIND_VERSION_1 1 __u32 version; #define IOMMU_PASID_FORMAT_INTEL_VTD 1 -#define IOMMU_PASID_FORMAT_LAST 2 +#define IOMMU_PASID_FORMAT_ARM_SMMU_V3 2 +#define IOMMU_PASID_FORMAT_LAST 3 __u32 format; __u32 addr_width; #define IOMMU_SVA_GPASID_VAL (1 << 0) /* guest PASID valid */ @@ -409,6 +410,21 @@ struct iommu_nesting_info_vtd { __u64 ecap_reg; }; +/* + * struct iommu_nesting_info_arm_smmuv3 - Arm SMMU-v3 nesting info. + */ +struct iommu_nesting_info_arm_smmuv3 { + __u32 flags; + __u16 asid_bits; + + /* Arm LPAE page table format as per kernel */ +#define ARM_PGTBL_32_LPAE_S1 (0x0) +#define ARM_PGTBL_64_LPAE_S1 (0x2) + __u8 pgtbl_fmt; + + __u8 padding[9]; +}; + /* * struct iommu_nesting_info - Information for nesting-capable IOMMU. * userspace should check it before using @@ -445,11 +461,13 @@ struct iommu_nesting_info_vtd { * +---------------+------------------------------------------------------+ * * data struct types defined for @format: - * +================================+=====================================+ - * | @format | data struct | - * +================================+=====================================+ - * | IOMMU_PASID_FORMAT_INTEL_VTD | struct iommu_nesting_info_vtd | - * +--------------------------------+-------------------------------------+ + * +================================+======================================+ + * | @format | data struct | + * +================================+======================================+ + * | IOMMU_PASID_FORMAT_INTEL_VTD | struct iommu_nesting_info_vtd | + * +---------------+-------------------------------------------------------+ + * | IOMMU_PASID_FORMAT_ARM_SMMU_V3 | struct iommu_nesting_info_arm_smmuv3 | + * +--------------------------------+--------------------------------------+ * */ struct iommu_nesting_info { @@ -466,6 +484,7 @@ struct iommu_nesting_info { /* Vendor specific data */ union { struct iommu_nesting_info_vtd vtd; + struct iommu_nesting_info_arm_smmuv3 smmuv3; } vendor; };
Add a vendor specific structure for domain nesting info for arm smmu-v3, and necessary info fields required to populate stage1 page tables. Signed-off-by: Vivek Gautam <vivek.gautam@arm.com> --- include/uapi/linux/iommu.h | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-)