The patch titled
Subject: KVM: use follow_pfnmap API
has been added to the -mm mm-unstable branch. Its filename is
kvm-use-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/kvm-use-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@xxxxxxxxxx>
Subject: KVM: use follow_pfnmap API
Date: Mon, 26 Aug 2024 16:43:44 -0400
Use the new pfnmap API to allow huge MMIO mappings for VMs. The rest work
is done perfectly on the other side (host_pfn_mapping_level()).
Link: https://lkml.kernel.org/r/20240826204353.2228736-11-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gavin Shan <gshan@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
--- a/virt/kvm/kvm_main.c~kvm-use-follow_pfnmap-api
+++ a/virt/kvm/kvm_main.c
@@ -2860,13 +2860,11 @@ static int hva_to_pfn_remapped(struct vm
unsigned long addr, bool write_fault,
bool *writable, kvm_pfn_t *p_pfn)
{
+ struct follow_pfnmap_args args = { .vma = vma, .address = addr };
kvm_pfn_t pfn;
- pte_t *ptep;
- pte_t pte;
- spinlock_t *ptl;
int r;
- r = follow_pte(vma, addr, &ptep, &ptl);
+ r = follow_pfnmap_start(&args);
if (r) {
/*
* get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
@@ -2881,21 +2879,19 @@ static int hva_to_pfn_remapped(struct vm
if (r)
return r;
- r = follow_pte(vma, addr, &ptep, &ptl);
+ r = follow_pfnmap_start(&args);
if (r)
return r;
}
- pte = ptep_get(ptep);
-
- if (write_fault && !pte_write(pte)) {
+ if (write_fault && !args.writable) {
pfn = KVM_PFN_ERR_RO_FAULT;
goto out;
}
if (writable)
- *writable = pte_write(pte);
- pfn = pte_pfn(pte);
+ *writable = args.writable;
+ pfn = args.pfn;
/*
* Get a reference here because callers of *hva_to_pfn* and
@@ -2916,9 +2912,8 @@ static int hva_to_pfn_remapped(struct vm
*/
if (!kvm_try_get_pfn(pfn))
r = -EFAULT;
-
out:
- pte_unmap_unlock(ptep, ptl);
+ follow_pfnmap_end(&args);
*p_pfn = pfn;
return r;
_
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
