Old kvm.ko versions only supported a tiny number of ioeventfds so
virtio-pci avoids ioeventfds when kvm_has_many_ioeventfds() returns 0.
Do not check kvm_has_many_ioeventfds() when KVM is disabled since it
always returns 0. Since commit 8c56c1a592
("memory: emulate ioeventfd") it has been possible to use ioeventfds in
qtest or TCG mode.
This patch makes -device virtio-blk-pci,iothread=iothread0 work even
when KVM is disabled.
I have tested that virtio-blk-pci works under TCG both with and without
iothread.
This patch fixes qemu-iotests 068, which was accidentally merged early
despite the dependency on ioeventfd.
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Tested-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20170628184724.21378-7-stefanha@redhat.com
Message-id: 20170615163813.7255-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
c324fd0a39