Commit 396bd6f3 authored Mar 02, 2021 by Jacob Pan Committed by Joerg Roedel Mar 18, 2021

iommu/vt-d: Calculate and set flags for handle_mm_fault

Page requests are originated from the user page fault. Therefore, we
shall set FAULT_FLAG_USER.

FAULT_FLAG_REMOTE indicates that we are walking an mm which is not
guaranteed to be the same as the current->mm and should not be subject
to protection key enforcement. Therefore, we should set FAULT_FLAG_REMOTE
to avoid faults when both SVM and PKEY are used.

References: commit 1b2ee126 ("mm/core: Do not enforce PKEY permissions on remote mm access")
Reviewed-by: Raj Ashok <ashok.raj@intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-5-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent 78a523fe

drivers/iommu/intel/svm.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -895,6 +895,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
		struct intel_iommu *iommu = d;
		struct intel_svm *svm = NULL;
		int head, tail, handled = 0;
		unsigned int flags = 0;

		/* Clear PPR bit before reading head/tail registers, to
		* ensure that we get a new interrupt if needed. */
		@@ -992,9 +993,11 @@ static irqreturn_t prq_event_thread(int irq, void *d)
		if (access_error(vma, req))
		goto invalid;

		ret = handle_mm_fault(vma, address,
		req->wr_req ? FAULT_FLAG_WRITE : 0,
		NULL);
		flags = FAULT_FLAG_USER \| FAULT_FLAG_REMOTE;
		if (req->wr_req)
		flags \|= FAULT_FLAG_WRITE;

		ret = handle_mm_fault(vma, address, flags, NULL);
		if (ret & VM_FAULT_ERROR)
		goto invalid;