Message ID | 772b20e270b3451aea9714260f2c40ddcc4afe80.1646422845.git.isaku.yamahata@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | KVM TDX basic feature support | expand |
On Fri, 2022-03-04 at 11:49 -0800, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > SPTE_PRIVATE_PROHIBIT specifies the share or private GPA is allowed or not. > It needs to be kept over zapping the EPT entry. Currently the EPT entry is > initialized shadow_init_value unconditionally to clear > SPTE_PRIVATE_PROHIBIT bit. To carry SPTE_PRIVATE_PROHIBIT bit, introduce a > helper function to get initial value for zapped entry with > SPTE_PRIVATE_PROHIBIT bit. Replace shadow_init_value with it. Isn't it better to merge patch 53-55, especially 54-55 together? > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/kvm/mmu/tdp_mmu.c | 19 +++++++++++++++---- > 1 file changed, 15 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index 1949f81027a0..6d750563824d 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -610,6 +610,12 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm, > return true; > } > > +static u64 shadow_init_spte(u64 old_spte) > +{ > + return shadow_init_value | > + (is_private_prohibit_spte(old_spte) ? SPTE_PRIVATE_PROHIBIT : 0); > +} > + > static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm, > struct tdp_iter *iter) > { > @@ -641,7 +647,8 @@ static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm, > * shadow_init_value (which sets "suppress #VE" bit) so it > * can be set when EPT table entries are zapped. > */ > - WRITE_ONCE(*rcu_dereference(iter->sptep), shadow_init_value); > + WRITE_ONCE(*rcu_dereference(iter->sptep), > + shadow_init_spte(iter->old_spte)); > > return true; > } In this and next patch (54-55), in all the code path, you already have the iter- >sptep, from which you can get the sp->private_sp, and check using is_private_sp(). Why do we need this SPTE_PRIVATE_PRORHIBIT bit? Are you suggesting we can have mixed private/shared mapping under a private_sp? > @@ -853,7 +860,8 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, > > if (!shared) { > /* see comments in tdp_mmu_zap_spte_atomic() */ > - tdp_mmu_set_spte(kvm, &iter, shadow_init_value); > + tdp_mmu_set_spte(kvm, &iter, > + shadow_init_spte(iter.old_spte)); > flush = true; > } else if (!tdp_mmu_zap_spte_atomic(kvm, &iter)) { > /* > @@ -1038,11 +1046,14 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, > new_spte = make_mmio_spte(vcpu, > tdp_iter_gfn_unalias(vcpu->kvm, iter), > pte_access); > - else > + else { > wrprot = make_spte(vcpu, sp, fault->slot, pte_access, > tdp_iter_gfn_unalias(vcpu->kvm, iter), > fault->pfn, iter->old_spte, fault->prefetch, > true, fault->map_writable, &new_spte); > + if (is_private_prohibit_spte(iter->old_spte)) > + new_spte |= SPTE_PRIVATE_PROHIBIT; > + } > > if (new_spte == iter->old_spte) > ret = RET_PF_SPURIOUS; > @@ -1335,7 +1346,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, > * invariant that the PFN of a present * leaf SPTE can never change. > * See __handle_changed_spte(). > */ > - tdp_mmu_set_spte(kvm, iter, shadow_init_value); > + tdp_mmu_set_spte(kvm, iter, shadow_init_spte(iter->old_spte)); > > if (!pte_write(range->pte)) { > new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte,
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 1949f81027a0..6d750563824d 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -610,6 +610,12 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm, return true; } +static u64 shadow_init_spte(u64 old_spte) +{ + return shadow_init_value | + (is_private_prohibit_spte(old_spte) ? SPTE_PRIVATE_PROHIBIT : 0); +} + static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm, struct tdp_iter *iter) { @@ -641,7 +647,8 @@ static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm, * shadow_init_value (which sets "suppress #VE" bit) so it * can be set when EPT table entries are zapped. */ - WRITE_ONCE(*rcu_dereference(iter->sptep), shadow_init_value); + WRITE_ONCE(*rcu_dereference(iter->sptep), + shadow_init_spte(iter->old_spte)); return true; } @@ -853,7 +860,8 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, if (!shared) { /* see comments in tdp_mmu_zap_spte_atomic() */ - tdp_mmu_set_spte(kvm, &iter, shadow_init_value); + tdp_mmu_set_spte(kvm, &iter, + shadow_init_spte(iter.old_spte)); flush = true; } else if (!tdp_mmu_zap_spte_atomic(kvm, &iter)) { /* @@ -1038,11 +1046,14 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, new_spte = make_mmio_spte(vcpu, tdp_iter_gfn_unalias(vcpu->kvm, iter), pte_access); - else + else { wrprot = make_spte(vcpu, sp, fault->slot, pte_access, tdp_iter_gfn_unalias(vcpu->kvm, iter), fault->pfn, iter->old_spte, fault->prefetch, true, fault->map_writable, &new_spte); + if (is_private_prohibit_spte(iter->old_spte)) + new_spte |= SPTE_PRIVATE_PROHIBIT; + } if (new_spte == iter->old_spte) ret = RET_PF_SPURIOUS; @@ -1335,7 +1346,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, * invariant that the PFN of a present * leaf SPTE can never change. * See __handle_changed_spte(). */ - tdp_mmu_set_spte(kvm, iter, shadow_init_value); + tdp_mmu_set_spte(kvm, iter, shadow_init_spte(iter->old_spte)); if (!pte_write(range->pte)) { new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte,