KVM: document lapic regs field

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 6f4ce2575d095edce570b7d15c0cd9724b6255ec..d29da25ea525f4bc22e6620d553c7400363aa058 100644 (file)
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -13,6 +13,11 @@ struct kvm_lapic {
        u32 divide_count;
        struct kvm_vcpu *vcpu;
        bool irr_pending;
+       /**
+        * APIC register page.  The layout matches the register layout seen by
+        * the guest 1:1, because it is accessed by the vmx microcode.
+        * Note: Only one register, the TPR, is used by the microcode.
+        */
        void *regs;
        gpa_t vapic_addr;
        struct page *vapic_page;