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>
This commit is contained in:
David Matlack 2015-12-30 08:26:17 -08:00 committed by Paolo Bonzini
parent def840ede3
commit 0af2593b2a

View File

@ -4024,10 +4024,12 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu)
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;