+ vfio-use-the-new-follow_pfnmap-api.patch added to mm-unstable branch

+ vfio-use-the-new-follow_pfnmap-api.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: vfio: use the new follow_pfnmap API
has been added to the -mm mm-unstable branch.  Its filename is
     vfio-use-the-new-follow_pfnmap-api.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vfio-use-the-new-follow_pfnmap-api.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Peter Xu <peterx@redhat.com>
Subject: vfio: use the new follow_pfnmap API
Date: Mon, 26 Aug 2024 16:43:47 -0400

Use the new API that can understand huge pfn mappings.

Link: https://lkml.kernel.org/r/20240826204353.2228736-14-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/vfio/vfio_iommu_type1.c |   16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

--- a/drivers/vfio/vfio_iommu_type1.c~vfio-use-the-new-follow_pfnmap-api
+++ a/drivers/vfio/vfio_iommu_type1.c
@@ -513,12 +513,10 @@ static int follow_fault_pfn(struct vm_ar
 			    unsigned long vaddr, unsigned long *pfn,
 			    bool write_fault)
 {
-	pte_t *ptep;
-	pte_t pte;
-	spinlock_t *ptl;
+	struct follow_pfnmap_args args = { .vma = vma, .address = vaddr };
 	int ret;
 
-	ret = follow_pte(vma, vaddr, &ptep, &ptl);
+	ret = follow_pfnmap_start(&args);
 	if (ret) {
 		bool unlocked = false;
 
@@ -532,19 +530,17 @@ static int follow_fault_pfn(struct vm_ar
 		if (ret)
 			return ret;
 
-		ret = follow_pte(vma, vaddr, &ptep, &ptl);
+		ret = follow_pfnmap_start(&args);
 		if (ret)
 			return ret;
 	}
 
-	pte = ptep_get(ptep);
-
-	if (write_fault && !pte_write(pte))
+	if (write_fault && !args.writable)
 		ret = -EFAULT;
 	else
-		*pfn = pte_pfn(pte);
+		*pfn = args.pfn;
 
-	pte_unmap_unlock(ptep, ptl);
+	follow_pfnmap_end(&args);
 	return ret;
 }
 
_

Patches currently in -mm which might be from peterx@redhat.com are

mm-dax-dump-start-address-in-fault-handler.patch
mm-mprotect-push-mmu-notifier-to-puds.patch
mm-powerpc-add-missing-pud-helpers.patch
mm-x86-make-pud_leaf-only-care-about-pse-bit.patch
mm-x86-implement-arch_check_zapped_pud.patch
mm-x86-add-missing-pud-helpers.patch
mm-mprotect-fix-dax-pud-handlings.patch
mm-introduce-arch_supports_huge_pfnmap-and-special-bits-to-pmd-pud.patch
mm-drop-is_huge_zero_pud.patch
mm-mark-special-bits-for-huge-pfn-mappings-when-inject.patch
mm-allow-thp-orders-for-pfnmaps.patch
mm-gup-detect-huge-pfnmap-entries-in-gup-fast.patch
mm-pagewalk-check-pfnmap-for-folio_walk_start.patch
mm-fork-accept-huge-pfnmap-entries.patch
mm-always-define-pxx_pgprot.patch
mm-new-follow_pfnmap-api.patch
kvm-use-follow_pfnmap-api.patch
s390-pci_mmio-use-follow_pfnmap-api.patch
mm-x86-pat-use-the-new-follow_pfnmap-api.patch
vfio-use-the-new-follow_pfnmap-api.patch
acrn-use-the-new-follow_pfnmap-api.patch
mm-access_process_vm-use-the-new-follow_pfnmap-api.patch
mm-remove-follow_pte.patch
mm-x86-support-large-pfn-mappings.patch
mm-arm64-support-large-pfn-mappings.patch