Auger Eric
2021-Feb-12 18:13 UTC
[PATCH 1/2] iommu: Report domain nesting info for arm-smmu-v3
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 at 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; > }; > >