On Tue, Sep 25, 2018 at 07:58:41PM +0200, Vitaly Kuznetsov wrote: > In preparation to MMU reconfiguration avoidance we need a space to > cache source data. As this partially intersects with kvm_mmu_page_role, > create 64bit sized union kvm_mmu_role holding both base and extended data. > No functional change. > > Signed-off-by: Vitaly Kuznetsov <[email protected]> > ---
One nit below, other than that... Reviewed-by: Sean Christopherson <[email protected]> > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index e59e5f49c8c2..bb1ef0f68f8e 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2359,7 +2359,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct > kvm_vcpu *vcpu, > int collisions = 0; > LIST_HEAD(invalid_list); > > - role = vcpu->arch.mmu->base_role; > + role = vcpu->arch.mmu->mmu_role.base; > role.level = level; > role.direct = direct; > if (role.direct) > @@ -4407,7 +4407,8 @@ static void reset_rsvds_bits_mask_ept(struct kvm_vcpu > *vcpu, > void > reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context) > { > - bool uses_nx = context->nx || context->base_role.smep_andnot_wp; > + bool uses_nx = context->nx || > + context->mmu_role.base.smep_andnot_wp; > struct rsvd_bits_validate *shadow_zero_check; > int i; > > @@ -4726,7 +4727,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) > { > struct kvm_mmu *context = vcpu->arch.mmu; > > - context->base_role.word = mmu_base_role_mask.word & > + context->mmu_role.base.word = mmu_base_role_mask.word & > kvm_calc_tdp_mmu_root_page_role(vcpu).word; > context->page_fault = tdp_page_fault; > context->sync_page = nonpaging_sync_page; > @@ -4807,7 +4808,7 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu) > else > paging32_init_context(vcpu, context); > > - context->base_role.word = mmu_base_role_mask.word & > + context->mmu_role.base.word = mmu_base_role_mask.word & > kvm_calc_shadow_mmu_root_page_role(vcpu).word; > reset_shadow_zero_bits_mask(vcpu, context); > } > @@ -4816,7 +4817,7 @@ EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu); > static union kvm_mmu_page_role > kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool > accessed_dirty) > { > - union kvm_mmu_page_role role = vcpu->arch.mmu->base_role; > + union kvm_mmu_page_role role = vcpu->arch.mmu->mmu_role.base; > > role.level = PT64_ROOT_4LEVEL; > role.direct = false; > @@ -4846,7 +4847,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, > bool execonly, > context->update_pte = ept_update_pte; > context->root_level = PT64_ROOT_4LEVEL; > context->direct_map = false; > - context->base_role.word = root_page_role.word & mmu_base_role_mask.word; > + context->mmu_role.base.word = > + root_page_role.word & mmu_base_role_mask.word; > context->get_pdptr = kvm_pdptr_read; > > update_permission_bitmask(vcpu, context, true); > @@ -5161,10 +5163,13 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, > gpa_t gpa, > > local_flush = true; > while (npte--) { > + unsigned int base_role = Nit: should this be a u32 to match mmu_role.base.word? > + vcpu->arch.mmu->mmu_role.base.word; > + > entry = *spte; > mmu_page_zap_pte(vcpu->kvm, sp, spte); > if (gentry && > - !((sp->role.word ^ vcpu->arch.mmu->base_role.word) > + !((sp->role.word ^ base_role) > & mmu_base_role_mask.word) && rmap_can_add(vcpu)) > mmu_pte_write_new_pte(vcpu, sp, spte, &gentry); > if (need_remote_flush(entry, *spte)) > @@ -5861,6 +5866,16 @@ int kvm_mmu_module_init(void) > { > int ret = -ENOMEM; > > + /* > + * MMU roles use union aliasing which is, generally speaking, an > + * undefined behavior. However, we supposedly know how compilers behave > + * and the current status quo is unlikely to change. Guardians below are > + * supposed to let us know if the assumption becomes false. > + */ > + BUILD_BUG_ON(sizeof(union kvm_mmu_page_role) != sizeof(u32)); > + BUILD_BUG_ON(sizeof(union kvm_mmu_extended_role) != sizeof(u32)); > + BUILD_BUG_ON(sizeof(union kvm_mmu_role) != sizeof(u64)); > + > kvm_mmu_reset_all_pte_masks(); > > pte_list_desc_cache = kmem_cache_create("pte_list_desc", > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 93ff08136fc1..c56a80c15c4f 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -9321,7 +9321,7 @@ static int nested_vmx_eptp_switching(struct kvm_vcpu > *vcpu, > > kvm_mmu_unload(vcpu); > mmu->ept_ad = accessed_dirty; > - mmu->base_role.ad_disabled = !accessed_dirty; > + mmu->mmu_role.base.ad_disabled = !accessed_dirty; > vmcs12->ept_pointer = address; > /* > * TODO: Check what's the correct approach in case > -- > 2.17.1 >
