On Sat, Oct 07, 2023, Like Xu wrote:
> On 14/7/2023 2:50 pm, Yan Zhao wrote:
> > Added helpers to check if KVM honors guest MTRRs.
> > The inner helper __kvm_mmu_honors_guest_mtrrs() is also provided to
> > outside callers for the purpose of checking if guest MTRRs were honored
> > before stopping non-coherent DMA.
> >
> > Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
> > ---
> > arch/x86/kvm/mmu.h | 7 +++++++
> > arch/x86/kvm/mmu/mmu.c | 15 +++++++++++++++
> > 2 files changed, 22 insertions(+)
> >
> > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> > index 92d5a1924fc1..38bd449226f6 100644
> > --- a/arch/x86/kvm/mmu.h
> > +++ b/arch/x86/kvm/mmu.h
> > @@ -235,6 +235,13 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
> > return -(u32)fault & errcode;
> > }
> > +bool __kvm_mmu_honors_guest_mtrrs(struct kvm *kvm, bool vm_has_noncoherent_dma);
> > +
> > +static inline bool kvm_mmu_honors_guest_mtrrs(struct kvm *kvm)
> > +{
> > + return __kvm_mmu_honors_guest_mtrrs(kvm, kvm_arch_has_noncoherent_dma(kvm));
> > +}
> > +
> > void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
> > int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);
> > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> > index 1e5db621241f..b4f89f015c37 100644
> > --- a/arch/x86/kvm/mmu/mmu.c
> > +++ b/arch/x86/kvm/mmu/mmu.c
> > @@ -4516,6 +4516,21 @@ static int kvm_tdp_mmu_page_fault(struct kvm_vcpu *vcpu,
> > }
> > #endif
> > +bool __kvm_mmu_honors_guest_mtrrs(struct kvm *kvm, bool vm_has_noncoherent_dma)
>
> According to the motivation provided in the comment, the function will no
> longer need to be passed the parameter "struct kvm *kvm" but will rely on
> the global parameters (plus vm_has_noncoherent_dma), removing "*kvm" ?
Yeah, I'll fixup the commit to drop @kvm from the inner helper. Thanks!
