Changeset 70413 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

Jan 2, 2018 7:22:26 AM (7 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

120018

Message:

VMM/HM: Nested Hw.virt: Implemented virtualized VMSAVE/VMLOAD to avoid intercepting them when supported by the CPU.

File:

• trunk/src/VBox/VMM/VMMR0/HMSVMR0.cpp (modified) (7 diffs)

trunk/src/VBox/VMM/VMMR0/HMSVMR0.cpp

@@ -166 +166 @@
                                                          | SVM_CTRL_INTERCEPT_VMRUN       \
                                                          | SVM_CTRL_INTERCEPT_VMMCALL     \
-                                                         | SVM_CTRL_INTERCEPT_VMLOAD      \
-                                                         | SVM_CTRL_INTERCEPT_VMSAVE      \
                                                          | SVM_CTRL_INTERCEPT_STGI        \
                                                          | SVM_CTRL_INTERCEPT_CLGI        \
@@ -817 +815 @@
     bool const fUseLbrVirt           = fLbrVirt; /** @todo CFGM etc. */
 
+    bool const fVirtVmsaveVmload     = RT_BOOL(pVM->hm.s.svm.u32Features & X86_CPUID_SVM_FEATURE_EDX_VIRT_VMSAVE_VMLOAD);
+    bool const fUseVirtVmsaveVmload  = fVirtVmsaveVmload && pVM->hm.s.svm.fVirtVmsaveVmload && pVM->hm.s.fNestedPaging;
+
     for (VMCPUID i = 0; i < pVM->cCpus; i++)
     {
@@ -885 +886 @@
         else
             Assert(pVmcb->ctrl.LbrVirt.n.u1LbrVirt == 0);
+
+        /* Virtualized VMSAVE/VMLOAD. */
+        pVmcb->ctrl.LbrVirt.n.u1VirtVmsaveVmload = fUseVirtVmsaveVmload;
+        if (!fUseVirtVmsaveVmload)
+        {
+            pVmcb->ctrl.u64InterceptCtrl |= SVM_CTRL_INTERCEPT_VMSAVE
+                                         |  SVM_CTRL_INTERCEPT_VMLOAD;
+        }
 
         /* Initially all VMCB clean bits MBZ indicating that everything should be loaded from the VMCB in memory. */
@@ -1906 +1915 @@
         pVmcbNstGst->ctrl.u64InterceptCtrl  |= pVmcb->ctrl.u64InterceptCtrl
                                             |  HMSVM_MANDATORY_GUEST_CTRL_INTERCEPTS;
-
         /*
          * Remove control intercepts that we don't need while executing the nested-guest.
@@ -1913 +1921 @@
          * other SVM instructions like VMSAVE when not intercept can cause havoc on the
          * host as they can write to any location in physical memory, hence they always
-         * need to be intercepted (they are included in HMSVM_MANDATORY_GUEST_CTRL_INTERCEPTS).
+         * need to be intercepted (see below).
          */
         Assert(   (pVmcbNstGst->ctrl.u64InterceptCtrl & HMSVM_MANDATORY_GUEST_CTRL_INTERCEPTS)
                == HMSVM_MANDATORY_GUEST_CTRL_INTERCEPTS);
         pVmcbNstGst->ctrl.u64InterceptCtrl  &= ~SVM_CTRL_INTERCEPT_VMMCALL;
+
+        /*
+         * If we don't expose Virtualized-VMSAVE/VMLOAD feature to the outer guest, we
+         * need to intercept VMSAVE/VMLOAD instructions executed by the nested-guest.
+         */
+        if (!pVCpu->CTX_SUFF(pVM)->cpum.ro.GuestFeatures.fSvmVirtVmsaveVmload)
+        {
+            pVmcbNstGst->ctrl.u64InterceptCtrl |= SVM_CTRL_INTERCEPT_VMSAVE
+                                               |  SVM_CTRL_INTERCEPT_VMLOAD;
+        }
 
         /* Finally, update the VMCB clean bits. */
@@ -7563 +7581 @@
     HMSVM_VALIDATE_EXIT_HANDLER_PARAMS();
 
+#ifdef VBOX_STRICT
+    PCSVMVMCB pVmcb = hmR0SvmGetCurrentVmcb(pVCpu, pCtx);
+    Assert(pVmcb);
+    Assert(!pVmcb->ctrl.LbrVirt.n.u1VirtVmsaveVmload);
+    RT_NOREF(pVmcb);
+#endif
+
     /** @todo Stat. */
     /* STAM_COUNTER_INC(&pVCpu->hm.s.StatExitVmload); */
@@ -7584 +7609 @@
 {
     HMSVM_VALIDATE_EXIT_HANDLER_PARAMS();
+
+#ifdef VBOX_STRICT
+    PCSVMVMCB pVmcb = hmR0SvmGetCurrentVmcb(pVCpu, pCtx);
+    Assert(pVmcb);
+    Assert(!pVmcb->ctrl.LbrVirt.n.u1VirtVmsaveVmload);
+    RT_NOREF(pVmcb);
+#endif
 
     /** @todo Stat. */