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 <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 123efd3..4107765 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -913,8 +913,7 @@
* 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 @@
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 @@
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 32d263f..820fc2e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -411,9 +411,7 @@
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 ea46d64..fa70c6e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -186,9 +186,12 @@
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);