| Message ID | 20200623194027.23135-2-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/mmu: Optimizations for kvm_get_mmu_page() | expand |
LGTM. Reviewed-By: Jon Cargille <jcargill@google.com> On Tue, Jun 23, 2020 at 12:40 PM Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > Refactor for_each_valid_sp() to take the list of shadow pages instead of > retrieving it from a gfn to avoid doing the gfn->list hash and lookup > multiple times during kvm_get_mmu_page(). > > Cc: Peter Feiner <pfeiner@google.com> > Cc: Jon Cargille <jcargill@google.com> > Cc: Jim Mattson <jmattson@google.com> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > arch/x86/kvm/mmu/mmu.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 3dd0af7e7515..67f8f82e9783 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -2258,15 +2258,14 @@ static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, > static void kvm_mmu_commit_zap_page(struct kvm *kvm, > struct list_head *invalid_list); > > - > -#define for_each_valid_sp(_kvm, _sp, _gfn) \ > - hlist_for_each_entry(_sp, \ > - &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \ > +#define for_each_valid_sp(_kvm, _sp, _list) \ > + hlist_for_each_entry(_sp, _list, hash_link) \ > if (is_obsolete_sp((_kvm), (_sp))) { \ > } else > > #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ > - for_each_valid_sp(_kvm, _sp, _gfn) \ > + for_each_valid_sp(_kvm, _sp, \ > + &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ > if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else > > static inline bool is_ept_sp(struct kvm_mmu_page *sp) > @@ -2477,6 +2476,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > unsigned int access) > { > union kvm_mmu_page_role role; > + struct hlist_head *sp_list; > unsigned quadrant; > struct kvm_mmu_page *sp; > bool need_sync = false; > @@ -2496,7 +2496,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; > role.quadrant = quadrant; > } > - for_each_valid_sp(vcpu->kvm, sp, gfn) { > + > + sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; > + for_each_valid_sp(vcpu->kvm, sp, sp_list) { > if (sp->gfn != gfn) { > collisions++; > continue; > @@ -2533,8 +2535,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > > sp->gfn = gfn; > sp->role = role; > - hlist_add_head(&sp->hash_link, > - &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]); > + hlist_add_head(&sp->hash_link, sp_list); > if (!direct) { > /* > * we should do write protection before syncing pages > -- > 2.26.0 >
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 3dd0af7e7515..67f8f82e9783 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2258,15 +2258,14 @@ static bool kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, static void kvm_mmu_commit_zap_page(struct kvm *kvm, struct list_head *invalid_list); - -#define for_each_valid_sp(_kvm, _sp, _gfn) \ - hlist_for_each_entry(_sp, \ - &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \ +#define for_each_valid_sp(_kvm, _sp, _list) \ + hlist_for_each_entry(_sp, _list, hash_link) \ if (is_obsolete_sp((_kvm), (_sp))) { \ } else #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ - for_each_valid_sp(_kvm, _sp, _gfn) \ + for_each_valid_sp(_kvm, _sp, \ + &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)]) \ if ((_sp)->gfn != (_gfn) || (_sp)->role.direct) {} else static inline bool is_ept_sp(struct kvm_mmu_page *sp) @@ -2477,6 +2476,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, unsigned int access) { union kvm_mmu_page_role role; + struct hlist_head *sp_list; unsigned quadrant; struct kvm_mmu_page *sp; bool need_sync = false; @@ -2496,7 +2496,9 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; role.quadrant = quadrant; } - for_each_valid_sp(vcpu->kvm, sp, gfn) { + + sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; + for_each_valid_sp(vcpu->kvm, sp, sp_list) { if (sp->gfn != gfn) { collisions++; continue; @@ -2533,8 +2535,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, sp->gfn = gfn; sp->role = role; - hlist_add_head(&sp->hash_link, - &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]); + hlist_add_head(&sp->hash_link, sp_list); if (!direct) { /* * we should do write protection before syncing pages
Refactor for_each_valid_sp() to take the list of shadow pages instead of retrieving it from a gfn to avoid doing the gfn->list hash and lookup multiple times during kvm_get_mmu_page(). Cc: Peter Feiner <pfeiner@google.com> Cc: Jon Cargille <jcargill@google.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/mmu/mmu.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)