Changeset 56025 in vbox for trunk/src/VBox/VMM/VMMAll/HMAll.cpp

Timestamp:

May 22, 2015 10:11:22 AM (10 years ago)

Author:

vboxsync

Message:

VMM/HM: Comments please, as I don't want to spend another 30 minutes wondering how this can be correct.

File:

• trunk/src/VBox/VMM/VMMAll/HMAll.cpp (modified) (3 diffs)

trunk/src/VBox/VMM/VMMAll/HMAll.cpp

@@ -55 +55 @@
 
 /**
- * Queues a page for invalidation
+ * Queues a guest page for invalidation.
  *
  * @returns VBox status code.
@@ -80 +80 @@
 
 /**
- * Invalidates a guest page
+ * Invalidates a guest page.
  *
  * @returns VBox status code.
@@ -215 +215 @@
 VMM_INT_DECL(int) HMInvalidatePageOnAllVCpus(PVM pVM, RTGCPTR GCPtr)
 {
+    /*
+     * The VT-x/AMD-V code will be flushing TLB each time a VCPU migrates to a different
+     * host CPU, see hmR0VmxFlushTaggedTlbBoth() and hmR0SvmFlushTaggedTlb().
+     *
+     * This is the reason why we do not care about thread preemption here and just
+     * execute HMInvalidatePage() assuming it might be the 'right' CPU.
+     */
     VMCPUID idCurCpu = VMMGetCpuId(pVM);
     STAM_COUNTER_INC(&pVM->aCpus[idCurCpu].hm.s.StatFlushPage);