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| author | Sean Christopherson <seanjc@google.com> | 2024-10-10 20:23:53 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-25 19:00:48 +0200 |
| commit | 93091f0fc7b7c7c76129cba9105269b4e70a7856 (patch) | |
| tree | 249843a0e4202fbc6feadc7a32b83af7d8fa4516 /arch/x86/kvm/vmx/vmx.c | |
| parent | KVM: VMX: Hold mmu_lock until page is released when updating APIC access page (diff) | |
| download | linux-93091f0fc7b7c7c76129cba9105269b4e70a7856.tar.xz linux-93091f0fc7b7c7c76129cba9105269b4e70a7856.zip | |
KVM: VMX: Use __kvm_faultin_page() to get APIC access page/pfn
Use __kvm_faultin_page() get the APIC access page so that KVM can
precisely release the refcounted page, i.e. to remove yet another user
of kvm_pfn_to_refcounted_page(). While the path isn't handling a guest
page fault, the semantics are effectively the same; KVM just happens to
be mapping the pfn into a VMCS field instead of a secondary MMU.
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-52-seanjc@google.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index bee90089c8a7..f6900bec4874 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6790,8 +6790,10 @@ void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu) struct kvm *kvm = vcpu->kvm; struct kvm_memslots *slots = kvm_memslots(kvm); struct kvm_memory_slot *slot; + struct page *refcounted_page; unsigned long mmu_seq; kvm_pfn_t pfn; + bool writable; /* Defer reload until vmcs01 is the current VMCS. */ if (is_guest_mode(vcpu)) { @@ -6827,7 +6829,7 @@ void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu) * controls the APIC-access page memslot, and only deletes the memslot * if APICv is permanently inhibited, i.e. the memslot won't reappear. */ - pfn = gfn_to_pfn_memslot(slot, gfn); + pfn = __kvm_faultin_pfn(slot, gfn, FOLL_WRITE, &writable, &refcounted_page); if (is_error_noslot_pfn(pfn)) return; @@ -6838,10 +6840,13 @@ void vmx_set_apic_access_page_addr(struct kvm_vcpu *vcpu) vmcs_write64(APIC_ACCESS_ADDR, pfn_to_hpa(pfn)); /* - * Do not pin apic access page in memory, the MMU notifier - * will call us again if it is migrated or swapped out. + * Do not pin the APIC access page in memory so that it can be freely + * migrated, the MMU notifier will call us again if it is migrated or + * swapped out. KVM backs the memslot with anonymous memory, the pfn + * should always point at a refcounted page (if the pfn is valid). */ - kvm_release_pfn_clean(pfn); + if (!WARN_ON_ONCE(!refcounted_page)) + kvm_release_page_clean(refcounted_page); /* * No need for a manual TLB flush at this point, KVM has already done a |