xen/passthrough: use gsi to map pirq when dom0 is PVH

xen/passthrough: use gsi to map pirq when dom0 is PVH

In PVH dom0, when passthrough a device to domU, QEMU code
xen_pt_realize->xc_physdev_map_pirq wants to use gsi, but in current codes
the gsi number is got from file /sys/bus/pci/devices/<sbdf>/irq, that is
wrong, because irq is not equal with gsi, they are in different spaces, so
pirq mapping fails.

To solve above problem, use new interface of Xen, xc_pcidev_get_gsi to get
gsi and use xc_physdev_map_pirq_gsi to map pirq when dom0 is PVH.

Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Acked-by: Anthony PERARD <anthony@xenproject.org>
Reviewed-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Message-Id: <20241106061418.3655304-1-Jiqian.Chen@amd.com>
Signed-off-by: Anthony PERARD <anthony.perard@vates.tech>