linux-kernel - [PATCH 1/1] iommu/vt-d: Remove control over Execute-Requested requests

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Date: Mon, 24 Jun 2024 11:23:51 +0800
From: Lu Baolu <baolu.lu@...ux.intel.com>
To: Joerg Roedel <joro@...tes.org>,
	Kevin Tian <kevin.tian@...el.com>,
	Yi Liu <yi.l.liu@...el.com>,
	Jacob Pan <jacob.jun.pan@...ux.intel.com>
Cc: Will Deacon <will@...nel.org>,
	Robin Murphy <robin.murphy@....com>,
	iommu@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 1/1] iommu/vt-d: Remove control over Execute-Requested requests

The VT-d specification has removed architectural support of the requests
with pasid with a value of 1 for Execute-Requested (ER). And the NXE bit
in the pasid table entry and XD bit in the first-stage paging Entries are
deprecated accordingly.

Remove the programming of these bits to make it consistent with the spec.

Suggested-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
 drivers/iommu/intel/iommu.h |  6 ++----
 drivers/iommu/intel/pasid.h | 10 ----------
 drivers/iommu/intel/iommu.c |  4 ++--
 drivers/iommu/intel/pasid.c |  1 -
 4 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index eaf015b4353b..9a3b064126de 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -49,7 +49,6 @@
 #define DMA_FL_PTE_US		BIT_ULL(2)
 #define DMA_FL_PTE_ACCESS	BIT_ULL(5)
 #define DMA_FL_PTE_DIRTY	BIT_ULL(6)
-#define DMA_FL_PTE_XD		BIT_ULL(63)
 
 #define DMA_SL_PTE_DIRTY_BIT	9
 #define DMA_SL_PTE_DIRTY	BIT_ULL(DMA_SL_PTE_DIRTY_BIT)
@@ -831,11 +830,10 @@ static inline void dma_clear_pte(struct dma_pte *pte)
 static inline u64 dma_pte_addr(struct dma_pte *pte)
 {
 #ifdef CONFIG_64BIT
-	return pte->val & VTD_PAGE_MASK & (~DMA_FL_PTE_XD);
+	return pte->val & VTD_PAGE_MASK;
 #else
 	/* Must have a full atomic 64-bit read */
-	return  __cmpxchg64(&pte->val, 0ULL, 0ULL) &
-			VTD_PAGE_MASK & (~DMA_FL_PTE_XD);
+	return  __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK;
 #endif
 }
 
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index da9978fef7ac..dde6d3ba5ae0 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -247,16 +247,6 @@ static inline void pasid_set_page_snoop(struct pasid_entry *pe, bool value)
 	pasid_set_bits(&pe->val[1], 1 << 23, value << 23);
 }
 
-/*
- * Setup No Execute Enable bit (Bit 133) of a scalable mode PASID
- * entry. It is required when XD bit of the first level page table
- * entry is about to be set.
- */
-static inline void pasid_set_nxe(struct pasid_entry *pe)
-{
-	pasid_set_bits(&pe->val[2], 1 << 5, 1 << 5);
-}
-
 /*
  * Setup the Page Snoop (PGSNP) field (Bit 88) of a scalable mode
  * PASID entry.
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 2e9811bf2a4e..0ea1f2183f93 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -854,7 +854,7 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 			domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
 			pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
 			if (domain->use_first_level)
-				pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
+				pteval |= DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
 
 			tmp = 0ULL;
 			if (!try_cmpxchg64(&pte->val, &tmp, pteval))
@@ -1872,7 +1872,7 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
 	attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP);
 	attr |= DMA_FL_PTE_PRESENT;
 	if (domain->use_first_level) {
-		attr |= DMA_FL_PTE_XD | DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
+		attr |= DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
 		if (prot & DMA_PTE_WRITE)
 			attr |= DMA_FL_PTE_DIRTY;
 	}
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index abce19e2ad6f..aabcdf756581 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -333,7 +333,6 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 	pasid_set_domain_id(pte, did);
 	pasid_set_address_width(pte, iommu->agaw);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
-	pasid_set_nxe(pte);
 
 	/* Setup Present and PASID Granular Transfer Type: */
 	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_FL_ONLY);
-- 
2.34.1