[PATCH v13 73/85] KVM: PPC: Remove extra get_page() to fix page refcount leak

Don't manually do get_page() when patching dcbz, as gfn_to_page() gifts
the caller a reference.  I.e. doing get_page() will leak the page due to
not putting all references.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/powerpc/kvm/book3s_pr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d7721297b9b6..cd7ab6d85090 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -652,7 +652,6 @@ static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
 	hpage_offset &= ~0xFFFULL;
 	hpage_offset /= 4;
 
-	get_page(hpage);
 	page = kmap_atomic(hpage);
 
 	/* patch dcbz into reserved instruction, so we trap */
-- 
2.47.0.rc1.288.g06298d1525-goog

• [PATCH v13 01/85] KVM: Drop KVM_ERR_PTR_BAD_PAGE and instead return NULL to indicate an error
• [PATCH v13 02/85] KVM: Allow calling kvm_release_page_{clean,dirty}() on a NULL page pointer
• [PATCH v13 03/85] KVM: Add kvm_release_page_unused() API to put pages that KVM never consumes
• [PATCH v13 04/85] KVM: x86/mmu: Skip the "try unsync" path iff the old SPTE was a leaf SPTE
• [PATCH v13 05/85] KVM: x86/mmu: Don't overwrite shadow-present MMU SPTEs when prefaulting
• [PATCH v13 06/85] KVM: x86/mmu: Invert @can_unsync and renamed to @synchronizing
• [PATCH v13 07/85] KVM: x86/mmu: Mark new SPTE as Accessed when synchronizing existing SPTE
• [PATCH v13 08/85] KVM: x86/mmu: Mark folio dirty when creating SPTE, not when zapping/modifying
• [PATCH v13 09/85] KVM: x86/mmu: Mark page/folio accessed only when zapping leaf SPTEs
• [PATCH v13 10/85] KVM: x86/mmu: Use gfn_to_page_many_atomic() when prefetching indirect PTEs
• [PATCH v13 11/85] KVM: Rename gfn_to_page_many_atomic() to kvm_prefetch_pages()
• [PATCH v13 12/85] KVM: Drop @atomic param from gfn=>pfn and hva=>pfn APIs
• [PATCH v13 13/85] KVM: Annotate that all paths in hva_to_pfn() might sleep
• [PATCH v13 14/85] KVM: Return ERR_SIGPENDING from hva_to_pfn() if GUP returns -EGAIN
• [PATCH v13 15/85] KVM: Drop extra GUP (via check_user_page_hwpoison()) to detect poisoned page
• [PATCH v13 16/85] KVM: Replace "async" pointer in gfn=>pfn with "no_wait" and error code
• [PATCH v13 17/85] KVM: x86/mmu: Drop kvm_page_fault.hva, i.e. don't track intermediate hva
• [PATCH v13 18/85] KVM: Drop unused "hva" pointer from __gfn_to_pfn_memslot()
• [PATCH v13 19/85] KVM: Introduce kvm_follow_pfn() to eventually replace "gfn_to_pfn" APIs
• [PATCH v13 20/85] KVM: Remove pointless sanity check on @map param to kvm_vcpu_(un)map()
• [PATCH v13 21/85] KVM: Explicitly initialize all fields at the start of kvm_vcpu_map()
• [PATCH v13 22/85] KVM: Use NULL for struct page pointer to indicate mremapped memory
• [PATCH v13 23/85] KVM: nVMX: Rely on kvm_vcpu_unmap() to track validity of eVMCS mapping
• [PATCH v13 24/85] KVM: nVMX: Drop pointless msr_bitmap_map field from struct nested_vmx
• [PATCH v13 25/85] KVM: nVMX: Add helper to put (unmap) vmcs12 pages
• [PATCH v13 26/85] KVM: Use plain "struct page" pointer instead of single-entry array
• [PATCH v13 27/85] KVM: Provide refcounted page as output field in struct kvm_follow_pfn
• [PATCH v13 28/85] KVM: Move kvm_{set,release}_page_{clean,dirty}() helpers up in kvm_main.c
• [PATCH v13 29/85] KVM: pfncache: Precisely track refcounted pages
• [PATCH v13 30/85] KVM: Migrate kvm_vcpu_map() to kvm_follow_pfn()
• [PATCH v13 31/85] KVM: Pin (as in FOLL_PIN) pages during kvm_vcpu_map()
• [PATCH v13 32/85] KVM: nVMX: Mark vmcs12's APIC access page dirty when unmapping
• [PATCH v13 33/85] KVM: Pass in write/dirty to kvm_vcpu_map(), not kvm_vcpu_unmap()
• [PATCH v13 34/85] KVM: Get writable mapping for __kvm_vcpu_map() only when necessary
• [PATCH v13 35/85] KVM: Disallow direct access (w/o mmu_notifier) to unpinned pfn by default
• [PATCH v13 36/85] KVM: x86: Don't fault-in APIC access page during initial allocation
• [PATCH v13 37/85] KVM: x86/mmu: Add "mmu" prefix fault-in helpers to free up generic names
• [PATCH v13 38/85] KVM: x86/mmu: Put direct prefetched pages via kvm_release_page_clean()
• [PATCH v13 39/85] KVM: x86/mmu: Add common helper to handle prefetching SPTEs
• [PATCH v13 40/85] KVM: x86/mmu: Add helper to "finish" handling a guest page fault
• [PATCH v13 41/85] KVM: x86/mmu: Mark pages/folios dirty at the origin of make_spte()
• [PATCH v13 42/85] KVM: Move declarations of memslot accessors up in kvm_host.h
• [PATCH v13 43/85] KVM: Add kvm_faultin_pfn() to specifically service guest page faults
• [PATCH v13 44/85] KVM: x86/mmu: Convert page fault paths to kvm_faultin_pfn()
• [PATCH v13 45/85] KVM: guest_memfd: Pass index, not gfn, to __kvm_gmem_get_pfn()
• [PATCH v13 46/85] KVM: guest_memfd: Provide "struct page" as output from kvm_gmem_get_pfn()
• [PATCH v13 47/85] KVM: x86/mmu: Put refcounted pages instead of blindly releasing pfns
• [PATCH v13 48/85] KVM: x86/mmu: Don't mark unused faultin pages as accessed
• [PATCH v13 49/85] KVM: Move x86's API to release a faultin page to common KVM
• [PATCH v13 50/85] KVM: VMX: Hold mmu_lock until page is released when updating APIC access page
• [PATCH v13 51/85] KVM: VMX: Use __kvm_faultin_page() to get APIC access page/pfn
• [PATCH v13 52/85] KVM: PPC: e500: Mark "struct page" dirty in kvmppc_e500_shadow_map()
• [PATCH v13 53/85] KVM: PPC: e500: Mark "struct page" pfn accessed before dropping mmu_lock
• [PATCH v13 54/85] KVM: PPC: e500: Use __kvm_faultin_pfn() to handle page faults
• [PATCH v13 55/85] KVM: arm64: Mark "struct page" pfns accessed/dirty before dropping mmu_lock
• [PATCH v13 56/85] KVM: arm64: Use __kvm_faultin_pfn() to handle memory aborts
• [PATCH v13 57/85] KVM: RISC-V: Mark "struct page" pfns dirty iff a stage-2 PTE is installed
• [PATCH v13 58/85] KVM: RISC-V: Mark "struct page" pfns accessed before dropping mmu_lock
• [PATCH v13 59/85] KVM: RISC-V: Use kvm_faultin_pfn() when mapping pfns into the guest
• [PATCH v13 60/85] KVM: PPC: Use __kvm_faultin_pfn() to handle page faults on Book3s HV
• [PATCH v13 61/85] KVM: PPC: Use __kvm_faultin_pfn() to handle page faults on Book3s Radix
• [PATCH v13 62/85] KVM: PPC: Drop unused @kvm_ro param from kvmppc_book3s_instantiate_page()
• [PATCH v13 63/85] KVM: PPC: Book3S: Mark "struct page" pfns dirty/accessed after installing PTE
• [PATCH v13 64/85] KVM: PPC: Use kvm_faultin_pfn() to handle page faults on Book3s PR
• [PATCH v13 65/85] KVM: LoongArch: Mark "struct page" pfns dirty only in "slow" page fault path
• [PATCH v13 66/85] KVM: LoongArch: Mark "struct page" pfns accessed only in "slow" page fault path
• [PATCH v13 67/85] KVM: LoongArch: Mark "struct page" pfn accessed before dropping mmu_lock
• [PATCH v13 68/85] KVM: LoongArch: Use kvm_faultin_pfn() to map pfns into the guest
• [PATCH v13 69/85] KVM: MIPS: Mark "struct page" pfns dirty only in "slow" page fault path
• [PATCH v13 70/85] KVM: MIPS: Mark "struct page" pfns accessed only in "slow" page fault path
• [PATCH v13 71/85] KVM: MIPS: Mark "struct page" pfns accessed prior to dropping mmu_lock
• [PATCH v13 72/85] KVM: MIPS: Use kvm_faultin_pfn() to map pfns into the guest
• [PATCH v13 73/85] KVM: PPC: Remove extra get_page() to fix page refcount leak
• [PATCH v13 74/85] KVM: PPC: Use kvm_vcpu_map() to map guest memory to patch dcbz instructions
• [PATCH v13 75/85] KVM: Convert gfn_to_page() to use kvm_follow_pfn()
• [PATCH v13 76/85] KVM: Add support for read-only usage of gfn_to_page()
• [PATCH v13 77/85] KVM: arm64: Use __gfn_to_page() when copying MTE tags to/from userspace
• [PATCH v13 78/85] KVM: PPC: Explicitly require struct page memory for Ultravisor sharing
• [PATCH v13 79/85] KVM: Drop gfn_to_pfn() APIs now that all users are gone
• [PATCH v13 80/85] KVM: s390: Use kvm_release_page_dirty() to unpin "struct page" memory
• [PATCH v13 81/85] KVM: Make kvm_follow_pfn.refcounted_page a required field
• [PATCH v13 82/85] KVM: x86/mmu: Don't mark "struct page" accessed when zapping SPTEs
• [PATCH v13 83/85] KVM: arm64: Don't mark "struct page" accessed when making SPTE young
• [PATCH v13 84/85] KVM: Drop APIs that manipulate "struct page" via pfns
• [PATCH v13 85/85] KVM: Don't grab reference on VM_MIXEDMAP pfns that have a "struct page"