Adds a rollback path to ivshmem_enable_irqfd() and fixes
ivshmem_disable_irqfd() to bail if irqfd has not been enabled.
To reproduce, run:
ivshmem-server -n 0
and QEMU with:
-device ivshmem-doorbell,chardev=iv
-chardev socket,path=/tmp/ivshmem_socket,id=iv
then load, unload, and load again the Windows driver, at the time of writing
available at:
https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/ivshmem
The issue is believed to have been masked by other guest drivers, notably
Linux ones, not enabling MSI-X on the device.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20171211072110.9058-4-lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
0b88dd9420