From a086f6a1ebc9d8d2d028b99e779ce0dbd9691dea Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Thu, 17 Apr 2014 17:06:12 +0800 Subject: [PATCH] Revert "KVM: Simplify kvm->tlbs_dirty handling" This reverts commit 5befdc385ddb2d5ae8995ad89004529a3acf58fc. Since we will allow flush tlb out of mmu-lock in the later patch Signed-off-by: Xiao Guangrong Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/paging_tmpl.h | 7 +++---- include/linux/kvm_host.h | 4 +--- virt/kvm/kvm_main.c | 5 ++++- 3 files changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 123efd3ec29f..410776528265 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -913,8 +913,7 @@ static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr, * and kvm_mmu_notifier_invalidate_range_start detect the mapping page isn't * used by guest then tlbs are not flushed, so guest is allowed to access the * freed pages. - * We set tlbs_dirty to let the notifier know this change and delay the flush - * until such a case actually happens. + * And we increase kvm->tlbs_dirty to delay tlbs flush in this case. */ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { @@ -943,7 +942,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return -EINVAL; if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { - vcpu->kvm->tlbs_dirty = true; + vcpu->kvm->tlbs_dirty++; continue; } @@ -958,7 +957,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) if (gfn != sp->gfns[i]) { drop_spte(vcpu->kvm, &sp->spt[i]); - vcpu->kvm->tlbs_dirty = true; + vcpu->kvm->tlbs_dirty++; continue; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 32d263f683dc..820fc2e1d9df 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -411,9 +411,7 @@ struct kvm { unsigned long mmu_notifier_seq; long mmu_notifier_count; #endif - /* Protected by mmu_lock */ - bool tlbs_dirty; - + long tlbs_dirty; struct list_head devices; }; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ea46d64c8e75..fa70c6e642b4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -186,9 +186,12 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) void kvm_flush_remote_tlbs(struct kvm *kvm) { + long dirty_count = kvm->tlbs_dirty; + + smp_mb(); if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) ++kvm->stat.remote_tlb_flush; - kvm->tlbs_dirty = false; + cmpxchg(&kvm->tlbs_dirty, dirty_count, 0); } EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);