qemu: Adjust qemu wakeup

Currently Xen hvm s3 has a bug coming from the difference between
qemu-traditioanl and qemu-xen. For qemu-traditional, the way to
resume from hvm s3 is via 'xl trigger' command. However, for
qemu-xen, the way to resume from hvm s3 inherited from standard
qemu, i.e. via QMP, and it doesn't work under Xen.

The root cause is, for qemu-xen, 'xl trigger' command didn't reset
devices, while QMP didn't unpause hvm domain though they did qemu
system reset.

We have two qemu patches and one xl patch to fix Xen hvm s3 bug.
This patch is the qemu patch 1. It adjusts qemu wakeup so that
Xen s3 resume logic (which will be implemented at qemu patch 2)
will be notified after qemu system reset.

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 4bc78a877252d772b983810a7d2c0be00e9be70e)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
qemu: Add qemu xen logic for Xen HVM S3 resume

This patch is qemu patch 2 to fix Xen HVM S3 bug, adding qemu
xen logic. When qemu wakeup, qemu xen logic is notified and
hypercall to xen hypervisor to unpause domain.

Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 11addd0ab9371af2b6ec028c7fe4e4c4992252fc)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>