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author | Xiao Guangrong <guangrong.xiao@linux.intel.com> | 2016-03-25 14:19:38 +0100 |
---|---|---|
committer | Radim Krčmář <rkrcmar@redhat.com> | 2016-04-20 15:29:17 +0200 |
commit | 46971a2f59f135341f8912f516540fef6890d4df (patch) | |
tree | a2489ff7acf6068bfcb1df35c16873b6abe8d840 /arch/x86 | |
parent | KVM: x86: optimize steal time calculation (diff) | |
download | linux-46971a2f59f135341f8912f516540fef6890d4df.tar.xz linux-46971a2f59f135341f8912f516540fef6890d4df.zip |
KVM: MMU: skip obsolete sp in for_each_gfn_*()
The obsolete sp should not be used on current vCPUs and should not hurt
vCPU's running, so skip it from for_each_gfn_sp() and
for_each_gfn_indirect_valid_sp()
The side effort is we will double check role.invalid in kvm_mmu_get_page()
but i think it is okay as role is well cached
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kvm/mmu.c | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 1ff4dbb73fb7..850335a71d9f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1909,18 +1909,17 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm, * since it has been deleted from active_mmu_pages but still can be found * at hast list. * - * for_each_gfn_indirect_valid_sp has skipped that kind of page and - * kvm_mmu_get_page(), the only user of for_each_gfn_sp(), has skipped - * all the obsolete pages. + * for_each_gfn_valid_sp() has skipped that kind of pages. */ -#define for_each_gfn_sp(_kvm, _sp, _gfn) \ +#define for_each_gfn_valid_sp(_kvm, _sp, _gfn) \ hlist_for_each_entry(_sp, \ &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \ - if ((_sp)->gfn != (_gfn)) {} else + if ((_sp)->gfn != (_gfn) || is_obsolete_sp((_kvm), (_sp)) \ + || (_sp)->role.invalid) {} else #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn) \ - for_each_gfn_sp(_kvm, _sp, _gfn) \ - if ((_sp)->role.direct || (_sp)->role.invalid) {} else + for_each_gfn_valid_sp(_kvm, _sp, _gfn) \ + if ((_sp)->role.direct) {} else /* @sp->gfn should be write-protected at the call site */ static bool __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, @@ -1961,6 +1960,11 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point) { } static void mmu_audit_disable(void) { } #endif +static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) +{ + return unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); +} + static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, struct list_head *invalid_list) { @@ -2105,11 +2109,6 @@ static void clear_sp_write_flooding_count(u64 *spte) __clear_sp_write_flooding_count(sp); } -static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp) -{ - return unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen); -} - static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gaddr, @@ -2136,10 +2135,7 @@ 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_gfn_sp(vcpu->kvm, sp, gfn) { - if (is_obsolete_sp(vcpu->kvm, sp)) - continue; - + for_each_gfn_valid_sp(vcpu->kvm, sp, gfn) { if (!need_sync && sp->unsync) need_sync = true; |