From: Xiao Guangrong Date: Fri, 25 Mar 2016 13:19:38 +0000 (+0800) Subject: KVM: MMU: skip obsolete sp in for_each_gfn_*() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=46971a2f59f135341f8912f516540fef6890d4df;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Paolo Bonzini --- 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;