From bb0f61533dfd6aa815a2719720c77d13f840b683 Mon Sep 17 00:00:00 2001
From: Jacob Pan <jacob.jun.pan@linux.intel.com>
Date: Tue, 2 Mar 2021 02:13:58 -0800
Subject: [PATCH] iommu/vt-d: Enable write protect propagation from guest
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.kumar@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-3-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/intel/pasid.c | 3 +++
include/uapi/linux/iommu.h | 3 ++-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 629e3aee44fed8..0bf7e0a768907c 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -732,6 +732,9 @@ 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)
+ pasid_set_wpe(pte);
}
if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_EAFE) {
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index e1d9e75f2c9471..59178fc229ca35 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;
--
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