Messages in this thread | | | Date | Mon, 22 Apr 2024 16:46:27 +0800 | Subject | Re: [PATCH 3/6] KVM: x86/mmu: Extract __kvm_mmu_do_page_fault() | From | Xiaoyao Li <> |
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On 4/19/2024 4:59 PM, Paolo Bonzini wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > Extract out __kvm_mmu_do_page_fault() from kvm_mmu_do_page_fault(). The > inner function is to initialize struct kvm_page_fault and to call the fault > handler, and the outer function handles updating stats and converting > return code.
I don't see how the outer function converts return code.
> KVM_PRE_FAULT_MEMORY will call the KVM page fault handler.
I assume it means the inner function will be used by KVM_PRE_FAULT_MEMORY.
> This patch makes the emulation_type always set irrelevant to the return > code. kvm_mmu_page_fault() is the only caller of kvm_mmu_do_page_fault(), > and references the value only when PF_RET_EMULATE is returned. Therefore, > this adjustment doesn't affect functionality.
This paragraph needs to be removed, I think. It's not true.
> No functional change intended. > > Suggested-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > Message-ID: <ddf1d98420f562707b11e12c416cce8fdb986bb1.1712785629.git.isaku.yamahata@intel.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > arch/x86/kvm/mmu/mmu_internal.h | 38 +++++++++++++++++++++------------ > 1 file changed, 24 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h > index e68a60974cf4..9baae6c223ee 100644 > --- a/arch/x86/kvm/mmu/mmu_internal.h > +++ b/arch/x86/kvm/mmu/mmu_internal.h > @@ -287,8 +287,8 @@ static inline void kvm_mmu_prepare_memory_fault_exit(struct kvm_vcpu *vcpu, > fault->is_private); > } > > -static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > - u64 err, bool prefetch, int *emulation_type) > +static inline int __kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > + u64 err, bool prefetch, int *emulation_type) > { > struct kvm_page_fault fault = { > .addr = cr2_or_gpa, > @@ -318,6 +318,27 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn); > } > > + if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && fault.is_tdp) > + r = kvm_tdp_page_fault(vcpu, &fault); > + else > + r = vcpu->arch.mmu->page_fault(vcpu, &fault); > + > + if (r == RET_PF_EMULATE && fault.is_private) { > + kvm_mmu_prepare_memory_fault_exit(vcpu, &fault); > + r = -EFAULT; > + } > + > + if (fault.write_fault_to_shadow_pgtable && emulation_type) > + *emulation_type |= EMULTYPE_WRITE_PF_TO_SP; > + > + return r; > +} > + > +static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > + u64 err, bool prefetch, int *emulation_type) > +{ > + int r; > + > /* > * Async #PF "faults", a.k.a. prefetch faults, are not faults from the > * guest perspective and have already been counted at the time of the > @@ -326,18 +347,7 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, > if (!prefetch) > vcpu->stat.pf_taken++; > > - if (IS_ENABLED(CONFIG_MITIGATION_RETPOLINE) && fault.is_tdp) > - r = kvm_tdp_page_fault(vcpu, &fault); > - else > - r = vcpu->arch.mmu->page_fault(vcpu, &fault); > - > - if (r == RET_PF_EMULATE && fault.is_private) { > - kvm_mmu_prepare_memory_fault_exit(vcpu, &fault); > - return -EFAULT; > - } > - > - if (fault.write_fault_to_shadow_pgtable && emulation_type) > - *emulation_type |= EMULTYPE_WRITE_PF_TO_SP; > + r = __kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, err, prefetch, emulation_type); > > /* > * Similar to above, prefetch faults aren't truly spurious, and the
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