kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa
The comment had the meaning of mmu.gva_to_gpa and nested_mmu.gva_to_gpa
swapped. Fix that, and also add some details describing how each translation
works.
Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7f5a82b..420a5ca 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4024,10 +4024,12 @@
g_context->inject_page_fault = kvm_inject_page_fault;
/*
- * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
- * translation of l2_gpa to l1_gpa addresses is done using the
- * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa
- * functions between mmu and nested_mmu are swapped.
+ * Note that arch.mmu.gva_to_gpa translates l2_gpa to l1_gpa using
+ * L1's nested page tables (e.g. EPT12). The nested translation
+ * of l2_gva to l1_gpa is done by arch.nested_mmu.gva_to_gpa using
+ * L2's page tables as the first level of translation and L1's
+ * nested page tables as the second level of translation. Basically
+ * the gva_to_gpa functions between mmu and nested_mmu are swapped.
*/
if (!is_paging(vcpu)) {
g_context->nx = false;