• Vitaly Kuznetsov's avatar
    KVM: x86: interrupt based APF 'page ready' event delivery · 2635b5c4
    Vitaly Kuznetsov authored
    Concerns were expressed around APF delivery via synthetic #PF exception as
    in some cases such delivery may collide with real page fault. For 'page
    ready' notifications we can easily switch to using an interrupt instead.
    Introduce new MSR_KVM_ASYNC_PF_INT mechanism and deprecate the legacy one.
    
    One notable difference between the two mechanisms is that interrupt may not
    get handled immediately so whenever we would like to deliver next event
    (regardless of its type) we must be sure the guest had read and cleared
    previous event in the slot.
    
    While on it, get rid on 'type 1/type 2' names for APF events in the
    documentation as they are causing confusion. Use 'page not present'
    and 'page ready' everywhere instead.
    Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
    Message-Id: <20200525144125.143875-6-vkuznets@redhat.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    2635b5c4
msr.rst 12.1 KB