The patch titled
Subject: mm/x86: support large pfn mappings
has been added to the -mm mm-unstable branch. Its filename is
mm-x86-support-large-pfn-mappings.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-x86-support-large-pfn-mappings.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@xxxxxxxxxx>
Subject: mm/x86: support large pfn mappings
Date: Mon, 26 Aug 2024 16:43:51 -0400
Helpers to install and detect special pmd/pud entries. In short, bit 9 on
x86 is not used for pmd/pud, so we can directly define them the same as
the pte level. One note is that it's also used in _PAGE_BIT_CPA_TEST but
that is only used in the debug test, and shouldn't conflict in this case.
One note is that pxx_set|clear_flags() for pmd/pud will need to be moved
upper so that they can be referenced by the new special bit helpers.
There's no change in the code that was moved.
Link: https://lkml.kernel.org/r/20240826204353.2228736-18-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gavin Shan <gshan@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 1
arch/x86/include/asm/pgtable.h | 80 ++++++++++++++++++++-----------
2 files changed, 53 insertions(+), 28 deletions(-)
--- a/arch/x86/include/asm/pgtable.h~mm-x86-support-large-pfn-mappings
+++ a/arch/x86/include/asm/pgtable.h
@@ -120,6 +120,34 @@ extern pmdval_t early_pmd_flags;
#define arch_end_context_switch(prev) do {} while(0)
#endif /* CONFIG_PARAVIRT_XXL */
+static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
+{
+ pmdval_t v = native_pmd_val(pmd);
+
+ return native_make_pmd(v | set);
+}
+
+static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear)
+{
+ pmdval_t v = native_pmd_val(pmd);
+
+ return native_make_pmd(v & ~clear);
+}
+
+static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
+{
+ pudval_t v = native_pud_val(pud);
+
+ return native_make_pud(v | set);
+}
+
+static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear)
+{
+ pudval_t v = native_pud_val(pud);
+
+ return native_make_pud(v & ~clear);
+}
+
/*
* The following only work if pte_present() is true.
* Undefined behaviour if not..
@@ -317,6 +345,30 @@ static inline int pud_devmap(pud_t pud)
}
#endif
+#ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
+static inline bool pmd_special(pmd_t pmd)
+{
+ return pmd_flags(pmd) & _PAGE_SPECIAL;
+}
+
+static inline pmd_t pmd_mkspecial(pmd_t pmd)
+{
+ return pmd_set_flags(pmd, _PAGE_SPECIAL);
+}
+#endif /* CONFIG_ARCH_SUPPORTS_PMD_PFNMAP */
+
+#ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
+static inline bool pud_special(pud_t pud)
+{
+ return pud_flags(pud) & _PAGE_SPECIAL;
+}
+
+static inline pud_t pud_mkspecial(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_SPECIAL);
+}
+#endif /* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */
+
static inline int pgd_devmap(pgd_t pgd)
{
return 0;
@@ -487,20 +539,6 @@ static inline pte_t pte_mkdevmap(pte_t p
return pte_set_flags(pte, _PAGE_SPECIAL|_PAGE_DEVMAP);
}
-static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
-{
- pmdval_t v = native_pmd_val(pmd);
-
- return native_make_pmd(v | set);
-}
-
-static inline pmd_t pmd_clear_flags(pmd_t pmd, pmdval_t clear)
-{
- pmdval_t v = native_pmd_val(pmd);
-
- return native_make_pmd(v & ~clear);
-}
-
/* See comments above mksaveddirty_shift() */
static inline pmd_t pmd_mksaveddirty(pmd_t pmd)
{
@@ -595,20 +633,6 @@ static inline pmd_t pmd_mkwrite_novma(pm
pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
#define pmd_mkwrite pmd_mkwrite
-static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
-{
- pudval_t v = native_pud_val(pud);
-
- return native_make_pud(v | set);
-}
-
-static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear)
-{
- pudval_t v = native_pud_val(pud);
-
- return native_make_pud(v & ~clear);
-}
-
/* See comments above mksaveddirty_shift() */
static inline pud_t pud_mksaveddirty(pud_t pud)
{
--- a/arch/x86/Kconfig~mm-x86-support-large-pfn-mappings
+++ a/arch/x86/Kconfig
@@ -28,6 +28,7 @@ config X86_64
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
select ARCH_SUPPORTS_PER_VMA_LOCK
+ select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
select HAVE_ARCH_SOFT_DIRTY
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx 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
