cirrus_vga: reset lfb_addr after a pci config write if the BAR is unmapped

If the cirrus_vga PCI BAR is unmapped than we should not only reset
map_addr but also lfb_addr, otherwise we'll keep trying to map
the old lfb_addr in map_linear_vram.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

hw/cirrus_vga.c

diff --git a/hw/cirrus_vga.c b/hw/cirrus_vga.c
index 722cac7..3c5043e 100644
--- a/hw/cirrus_vga.c
+++ b/hw/cirrus_vga.c
@@ -3088,8 +3088,11 @@
     CirrusVGAState *s = &pvs->cirrus_vga;
 
     pci_default_write_config(d, address, val, len);
-    if (s->vga.map_addr && d->io_regions[0].addr == PCI_BAR_UNMAPPED)
+    if (s->vga.map_addr && d->io_regions[0].addr == PCI_BAR_UNMAPPED) {
         s->vga.map_addr = 0;
+        s->vga.lfb_addr = 0;
+        s->vga.lfb_end = 0;
+    }
     cirrus_update_memory_access(s);
 }