[Qemu-devel] [PATCH 1/1] qmp, hmp: make subsystem/system-vendor identities optional

["Denis V. Lunev" <den@openvz.org>]

According to PCI specification subsystem id and subsystem vendor id are
optinal and could be abscent in Type1 header and can be found on
different offsets within Type0 and Type2 headers.

Thus we should make this data optional in struct PciDeviceId and skip
reporting them via HMP if the information is not available.

Additional (wrong information) about PCI bridges (Type1 devices) has been
added in 5383a705 and fortunately not released. This patch fixes that
problem. The problem was spotted by Markus.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
---
 hmp.c          |  6 ++++--
 hw/pci/pci.c   | 13 ++++++++++---
 qapi/misc.json |  4 ++--
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/hmp.c b/hmp.c
index 3a9f797677..55633d29a3 100644
--- a/hmp.c
+++ b/hmp.c
@@ -824,8 +824,10 @@ static void hmp_info_pci_device(Monitor *mon, const PciDeviceInfo *dev)
 
     monitor_printf(mon, ": PCI device %04" PRIx64 ":%04" PRIx64 "\n",
                    dev->id->vendor, dev->id->device);
-    monitor_printf(mon, "      PCI subsystem %04" PRIx64 ":%04" PRIx64 "\n",
-                   dev->id->subsystem_vendor, dev->id->subsystem);
+    if (dev->id->has_subsystem_vendor && dev->id->has_subsystem) {
+        monitor_printf(mon, "      PCI subsystem %04" PRIx64 ":%04" PRIx64 "\n",
+                       dev->id->subsystem_vendor, dev->id->subsystem);
+    }
 
     if (dev->has_irq) {
         monitor_printf(mon, "      IRQ %" PRId64 ".\n", dev->irq);
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 51d0dec466..b937f0dc0a 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1737,9 +1737,6 @@ static PciDeviceInfo *qmp_query_pci_device(PCIDevice *dev, PCIBus *bus,
     info->id = g_new0(PciDeviceId, 1);
     info->id->vendor = pci_get_word(dev->config + PCI_VENDOR_ID);
     info->id->device = pci_get_word(dev->config + PCI_DEVICE_ID);
-    info->id->subsystem = pci_get_word(dev->config + PCI_SUBSYSTEM_ID);
-    info->id->subsystem_vendor =
-        pci_get_word(dev->config + PCI_SUBSYSTEM_VENDOR_ID);
     info->regions = qmp_query_pci_regions(dev);
     info->qdev_id = g_strdup(dev->qdev.id ? dev->qdev.id : "");
 
@@ -1752,6 +1749,16 @@ static PciDeviceInfo *qmp_query_pci_device(PCIDevice *dev, PCIBus *bus,
     if (type == PCI_HEADER_TYPE_BRIDGE) {
         info->has_pci_bridge = true;
         info->pci_bridge = qmp_query_pci_bridge(dev, bus, bus_num);
+    } else if (type == PCI_HEADER_TYPE_NORMAL) {
+        info->id->has_subsystem = info->id->has_subsystem_vendor = true;
+        info->id->subsystem = pci_get_word(dev->config + PCI_SUBSYSTEM_ID);
+        info->id->subsystem_vendor =
+            pci_get_word(dev->config + PCI_SUBSYSTEM_VENDOR_ID);
+    } else if (type == PCI_HEADER_TYPE_CARDBUS) {
+        info->id->has_subsystem = info->id->has_subsystem_vendor = true;
+        info->id->subsystem = pci_get_word(dev->config + PCI_CB_SUBSYSTEM_ID);
+        info->id->subsystem_vendor =
+            pci_get_word(dev->config + PCI_CB_SUBSYSTEM_VENDOR_ID);
     }
 
     return info;
diff --git a/qapi/misc.json b/qapi/misc.json
index ada9af5add..95a6ed022d 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -839,8 +839,8 @@
 # Since: 2.4
 ##
 { 'struct': 'PciDeviceId',
-  'data': {'device': 'int', 'vendor': 'int', 'subsystem': 'int',
-            'subsystem-vendor': 'int'} }
+  'data': {'device': 'int', 'vendor': 'int', '*subsystem': 'int',
+            '*subsystem-vendor': 'int'} }
 
 ##
 # @PciDeviceInfo:
-- 
2.17.1