[Qemu-devel] [PATCH] xen-pt: Fix PCI devices re-attach failed

[Liang Li <liang.z.li@intel.com>]

Use the 'xl pci-attach $DomU $BDF' command to attach more then
one PCI devices to the guest, then detach the devices with
'xl pci-detach $DomU $BDF', after that, re-attach these PCI
devices again, an error message will be reported like following:

libxl: error: libxl_qmp.c:287:qmp_handle_error_response: receive
an error message from QMP server: Duplicate ID 'pci-pt-03_10.1'
for device.

The count of calling xen_pt_region_add and xen_pt_region_del are
not the same will cause the XenPCIPassthroughState and it's related
QemuOpts object not be released properly.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reported-by: Longtao Pang <longtaox.pang@intel.com>
---
 hw/xen/xen_pt.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index c1bf357..523b8a2 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -588,7 +588,6 @@ static void xen_pt_region_add(MemoryListener *l, MemoryRegionSection *sec)
     XenPCIPassthroughState *s = container_of(l, XenPCIPassthroughState,
                                              memory_listener);
 
-    memory_region_ref(sec->mr);
     xen_pt_region_update(s, sec, true);
 }
 
@@ -598,7 +597,6 @@ static void xen_pt_region_del(MemoryListener *l, MemoryRegionSection *sec)
                                              memory_listener);
 
     xen_pt_region_update(s, sec, false);
-    memory_region_unref(sec->mr);
 }
 
 static void xen_pt_io_region_add(MemoryListener *l, MemoryRegionSection *sec)
@@ -606,7 +604,6 @@ static void xen_pt_io_region_add(MemoryListener *l, MemoryRegionSection *sec)
     XenPCIPassthroughState *s = container_of(l, XenPCIPassthroughState,
                                              io_listener);
 
-    memory_region_ref(sec->mr);
     xen_pt_region_update(s, sec, true);
 }
 
@@ -616,7 +613,6 @@ static void xen_pt_io_region_del(MemoryListener *l, MemoryRegionSection *sec)
                                              io_listener);
 
     xen_pt_region_update(s, sec, false);
-    memory_region_unref(sec->mr);
 }
 
 static const MemoryListener xen_pt_memory_listener = {
-- 
1.9.1