Write protect bit, when set, inhibits supervisor writes to the read-only pages. In guest supervisor shared virtual addressing (SVA), write-protect should be honored upon guest bind supervisor PASID request.
This patch extends the VT-d portion of the IOMMU UAPI to include WP bit. WPE bit of the supervisor PASID entry will be set to match CPU CR0.WP bit. Signed-off-by: Sanjay Kumar <sanjay.k.ku...@intel.com> Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> --- drivers/iommu/intel/pasid.c | 5 +++++ include/uapi/linux/iommu.h | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index 0b7e0e726ade..c7a2ec930af4 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -763,6 +763,11 @@ intel_pasid_setup_bind_data(struct intel_iommu *iommu, struct pasid_entry *pte, return -EINVAL; } pasid_set_sre(pte); + /* Enable write protect WP if guest requested */ + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_WPE) { + if (pasid_enable_wpe(pte)) + return -EINVAL; + } } if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_EAFE) { diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h index 68cb558fe8db..33f3dc7a91de 100644 --- a/include/uapi/linux/iommu.h +++ b/include/uapi/linux/iommu.h @@ -288,7 +288,8 @@ struct iommu_gpasid_bind_data_vtd { #define IOMMU_SVA_VTD_GPASID_PWT (1 << 3) /* page-level write through */ #define IOMMU_SVA_VTD_GPASID_EMTE (1 << 4) /* extended mem type enable */ #define IOMMU_SVA_VTD_GPASID_CD (1 << 5) /* PASID-level cache disable */ -#define IOMMU_SVA_VTD_GPASID_LAST (1 << 6) +#define IOMMU_SVA_VTD_GPASID_WPE (1 << 6) /* Write protect enable */ +#define IOMMU_SVA_VTD_GPASID_LAST (1 << 7) __u64 flags; __u32 pat; __u32 emt; -- 2.25.1