On Wed, May 10, 2023 at 01:39:25PM +0800, Chao Gao wrote: > On Tue, May 09, 2023 at 09:51:43PM +0800, Yan Zhao wrote: > >Call new helper kvm_zap_gfn_for_memtype() to skip zap mmu if EPT is not > >enabled. > > > >When guest MTRR changes and it's desired to zap TDP entries to remove > >stale mappings, only do it when EPT is enabled, because only memory type > >of EPT leaf is affected by guest MTRR with noncoherent DMA present. > > > >Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx> > >--- > > arch/x86/kvm/mtrr.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > >diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c > >index 9fac1ec03463..62ebb9978156 100644 > >--- a/arch/x86/kvm/mtrr.c > >+++ b/arch/x86/kvm/mtrr.c > >@@ -330,7 +330,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr) > > var_mtrr_range(&mtrr_state->var_ranges[index], &start, &end); > > } > > > >- kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end)); > >+ kvm_zap_gfn_for_memtype(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end)); > > I am wondering if the check of shadow_memtype_mask (now inside the > kvm_zap_gfn_for_memtype()) should be moved to the beginning of update_mtrr(). > Because if EPT isn't enabled, computing @start/@end is useless and can be > skipped. No, shadow_memtype_mask is not accessible in mtrr.c. It's better to confine it in mmu related files, e.g. mmu/mmu.c, mmu/spte.c > > > } > > > > static bool var_mtrr_range_is_valid(struct kvm_mtrr_range *range) > >-- > >2.17.1 > >
