From: David Stevens <stevensd@xxxxxxxxxxxx> Switch the x86 mmu to the new gfn_to_pfn_noref functions. This allows IO and PFNMAP mappings backed with valid struct pages but without refcounting (e.g. tail pages of non-compound higher order allocations) to be mapped into the guest. Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 19 ++++++++++--------- arch/x86/kvm/mmu/mmu_internal.h | 1 + arch/x86/kvm/mmu/paging_tmpl.h | 7 ++++--- arch/x86/kvm/x86.c | 5 +++-- 4 files changed, 18 insertions(+), 14 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 144c5a01cd77..86b74e7bccfa 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3114,7 +3114,7 @@ void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault if (unlikely(fault->max_level == PG_LEVEL_4K)) return; - if (is_error_noslot_pfn(fault->pfn)) + if (!fault->page) return; if (kvm_slot_dirty_track_enabled(slot)) @@ -4224,6 +4224,7 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault if (is_guest_mode(vcpu)) { fault->slot = NULL; fault->pfn = KVM_PFN_NOSLOT; + fault->page = NULL; fault->map_writable = false; return RET_PF_CONTINUE; } @@ -4239,9 +4240,9 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault } async = false; - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, false, &async, - fault->write, &fault->map_writable, - &fault->hva); + fault->pfn = __gfn_to_pfn_noref_memslot(slot, fault->gfn, false, false, &async, + fault->write, &fault->map_writable, + &fault->hva, &fault->page); if (!async) return RET_PF_CONTINUE; /* *pfn has correct page already */ @@ -4261,9 +4262,9 @@ static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault * to wait for IO. Note, gup always bails if it is unable to quickly * get a page and a fatal signal, i.e. SIGKILL, is pending. */ - fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, true, NULL, - fault->write, &fault->map_writable, - &fault->hva); + fault->pfn = __gfn_to_pfn_noref_memslot(slot, fault->gfn, false, true, NULL, + fault->write, &fault->map_writable, + &fault->hva, &fault->page); return RET_PF_CONTINUE; } @@ -4349,7 +4350,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault out_unlock: write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_noref_clean(fault->pfn, fault->page); return r; } @@ -4427,7 +4428,7 @@ static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu, out_unlock: read_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_noref_clean(fault->pfn, fault->page); return r; } #endif diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 2cbb155c686c..6ee34a2d0e13 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -239,6 +239,7 @@ struct kvm_page_fault { unsigned long mmu_seq; kvm_pfn_t pfn; hva_t hva; + struct page *page; bool map_writable; /* diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index a056f2773dd9..e4e54e372721 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -525,6 +525,7 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, unsigned pte_access; gfn_t gfn; kvm_pfn_t pfn; + struct page *page; if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte)) return false; @@ -540,12 +541,12 @@ FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, if (!slot) return false; - pfn = gfn_to_pfn_memslot_atomic(slot, gfn); + pfn = gfn_to_pfn_noref_memslot_atomic(slot, gfn, &page); if (is_error_pfn(pfn)) return false; mmu_set_spte(vcpu, slot, spte, pte_access, gfn, pfn, NULL); - kvm_release_pfn_clean(pfn); + kvm_release_pfn_noref_clean(pfn, page); return true; } @@ -830,7 +831,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault out_unlock: write_unlock(&vcpu->kvm->mmu_lock); - kvm_release_pfn_clean(fault->pfn); + kvm_release_pfn_noref_clean(fault->pfn, fault->page); return r; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 237c483b1230..53a8c9e776e5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8458,6 +8458,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, { gpa_t gpa = cr2_or_gpa; kvm_pfn_t pfn; + struct page *page; if (!(emulation_type & EMULTYPE_ALLOW_RETRY_PF)) return false; @@ -8487,7 +8488,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, * retry instruction -> write #PF -> emulation fail -> retry * instruction -> ... */ - pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa)); + pfn = gfn_to_pfn_noref(vcpu->kvm, gpa_to_gfn(gpa), &page); /* * If the instruction failed on the error pfn, it can not be fixed, @@ -8496,7 +8497,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, if (is_error_noslot_pfn(pfn)) return false; - kvm_release_pfn_clean(pfn); + kvm_release_pfn_noref_clean(pfn, page); /* The instructions are well-emulated on direct mmu. */ if (vcpu->arch.mmu->root_role.direct) { -- 2.40.0.348.gf938b09366-goog