• Michael S. Tsirkin's avatar
    KVM: dont clear TMR on EOI · a0c9a822
    Michael S. Tsirkin authored
    Intel spec says that TMR needs to be set/cleared
    when IRR is set, but kvm also clears it on  EOI.
    I did some tests on a real (AMD based) system,
    and I see same TMR values both before
    and after EOI, so I think it's a minor bug in kvm.
    This patch fixes TMR to be set/cleared on IRR set
    only as per spec.
    And now that we don't clear TMR, we can save
    an atomic read of TMR on EOI that's not propagated
    to ioapic, by checking whether ioapic needs
    a specific vector first and calculating
    the mode afterwards.
    Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
    Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
ioapic.c 11 KB