When disabling MSI/X interrupts the disable functions will leave the
device in INTx mode (when available). This matches how hardware
operates, INTx is enabled unless MSI/X is enabled (DisINTx is handled
separately). Therefore when we really want to disable all interrupts,
such as when removing the device, and we start with the device in
MSI/X mode, we need to pass through INTx on our way to being
completely quiesced.
In well behaved situations, the guest driver will have shutdown the
device and it will start vfio_exitfn() in INTx mode, producing the
desired result. If hot-unplug causes the guest to crash, we may get
the device in MSI/X state, which will leave QEMU with a bogus handler
installed.
Fix this by re-ordering our disable routine so that it should always
finish in VFIO_INT_NONE state, which is what all callers expect.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
b3e27c3aee