diff options
| author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-12-01 22:32:03 -0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2008-12-31 16:55:43 +0200 |
| commit | b1a368218ad5b6e62380c8f206f16e6f18bf154c (patch) | |
| tree | 4c13c3bd259032d19255637dcff4001e970de6ae | |
| parent | 60c8aec6e2c9923492dabbd6b67e34692bd26c20 (diff) | |
KVM: MMU: collapse remote TLB flushes on root sync
Collapse remote TLB flushes on root sync.
kernbench is 2.7% faster on 4-way guest. Improvements have been seen
with other loads such as AIM7.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7ce92f78f33..58c35dead32 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -621,7 +621,7 @@ static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) return NULL; } -static void rmap_write_protect(struct kvm *kvm, u64 gfn) +static int rmap_write_protect(struct kvm *kvm, u64 gfn) { unsigned long *rmapp; u64 *spte; @@ -667,8 +667,7 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn) spte = rmap_next(kvm, rmapp, spte); } - if (write_protected) - kvm_flush_remote_tlbs(kvm); + return write_protected; } static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp) @@ -1083,7 +1082,8 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return 1; } - rmap_write_protect(vcpu->kvm, sp->gfn); + if (rmap_write_protect(vcpu->kvm, sp->gfn)) + kvm_flush_remote_tlbs(vcpu->kvm); kvm_unlink_unsync_page(vcpu->kvm, sp); if (vcpu->arch.mmu.sync_page(vcpu, sp)) { kvm_mmu_zap_page(vcpu->kvm, sp); @@ -1162,6 +1162,14 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, kvm_mmu_pages_init(parent, &parents, &pages); while (mmu_unsync_walk(parent, &pages)) { + int protected = 0; + + for_each_sp(pages, sp, parents, i) + protected |= rmap_write_protect(vcpu->kvm, sp->gfn); + + if (protected) + kvm_flush_remote_tlbs(vcpu->kvm); + for_each_sp(pages, sp, parents, i) { kvm_sync_page(vcpu, sp); mmu_pages_clear_parents(&parents); @@ -1226,7 +1234,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, sp->role = role; hlist_add_head(&sp->hash_link, bucket); if (!metaphysical) { - rmap_write_protect(vcpu->kvm, gfn); + if (rmap_write_protect(vcpu->kvm, gfn)) + kvm_flush_remote_tlbs(vcpu->kvm); account_shadowed(vcpu->kvm, gfn); } if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) |