From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Subject: Re: [PATCH v1 RESEND 6/9] x86/kvm/mmu: make space for source data caching in struct kvm_mmu Date: Wed, 19 Sep 2018 08:30:52 -0700 Message-ID: <1537371052.9937.33.camel@intel.com> References: <20180918160906.9241-1-vkuznets@redhat.com> <20180918160906.9241-7-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Cc: Paolo Bonzini , Radim =?UTF-8?Q?Kr=C4=8Dm=C3=A1=C5=99?= , Jim Mattson , Liran Alon , linux-kernel@vger.kernel.org To: Vitaly Kuznetsov , kvm@vger.kernel.org Return-path: In-Reply-To: <20180918160906.9241-7-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Tue, 2018-09-18 at 18:09 +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_role and > extended data. No functional change. > > Signed-off-by: Vitaly Kuznetsov > --- >  arch/x86/include/asm/kvm_host.h | 14 +++++++++++++- >  arch/x86/kvm/mmu.c              | 19 ++++++++++++------- >  arch/x86/kvm/vmx.c              |  2 +- >  3 files changed, 26 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 527aaf45eba6..6ca7d28d57e9 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -273,6 +273,18 @@ union kvm_mmu_page_role { >   }; >  }; >   > +union kvm_mmu_scache { What about "kvm_mmu_extended_role" and a variable name of "ext"? scache might be interpreted as "shadow cache", whereas I think you intend "source cache".  And it isn't immediately clear (to me) what "source" refers to. > + unsigned int word; > +}; > + > + unsigned long as_u64; > + struct { > + union kvm_mmu_page_role base_role; Would it make sense to shorten this to simply "base"?  The usage looks like it's always deferenced in the context of kvm_mmu_role, i.e. the "role" part appears to be redundant.  And if scache were renamed we'd end up with e.g. mmu_role.base and mmu_role.ext. > + union kvm_mmu_scache scache; > + }; > +}; > + >  struct kvm_rmap_head { >   unsigned long val; >  }; > @@ -360,7 +372,7 @@ struct kvm_mmu { >   void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, >      u64 *spte, const void *pte); >   hpa_t root_hpa; > - union kvm_mmu_page_role base_role; > + union kvm_mmu_role mmu_role; >   u8 root_level; >   u8 shadow_root_level; >   u8 ept_ad; > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 5f167823c50d..8d8e6fa75fa3 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; >   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_role.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_role.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_role.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; >   >   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_role.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 = > + vcpu->arch.mmu->mmu_role.base_role.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)) > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 29af40b9239f..79e0b0570dd1 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -9290,7 +9290,7 @@ 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_role.ad_disabled = !accessed_dirty; >   vmcs12->ept_pointer = address; >   /* >    * TODO: Check what's the correct approach in case