Index: /trunk/src/VBox/VMM/VMMSwitcher/AMD64andLegacy.mac
===================================================================
--- /trunk/src/VBox/VMM/VMMSwitcher/AMD64andLegacy.mac	(revision 37968)
+++ /trunk/src/VBox/VMM/VMMSwitcher/AMD64andLegacy.mac	(revision 37969)
@@ -1102,5 +1102,16 @@
     ; the fpu stuff must be done before we restore cr0.
     mov     rcx, [rdx + r8 + CPUMCPU.Host.cr4]
+    test    rcx, X86_CR4_PCIDE
+    jz      gth_no_pcide
+    mov     rax, [rdx + r8 + CPUMCPU.Host.cr3]
+    and     rax, ~0xfff                 ; clear the PCID in cr3
+    mov     cr3, rax
     mov     cr4, rcx
+    mov     rax, [rdx + r8 + CPUMCPU.Host.cr3]
+    mov     cr3, rax                    ; reload it with the right PCID.
+    jmp     gth_restored_cr4
+gth_no_pcide:
+    mov     cr4, rcx
+gth_restored_cr4:
     mov     rcx, [rdx + r8 + CPUMCPU.Host.cr0]
     mov     cr0, rcx