[libvirt] [PATCH] Fix explicit usage of default video PCI slots

[Ján Tomko]

Don't set the PCI address of primary video to the default
if it's already occupied by another device.

Without this, a primary video card that doesn't have an
address gets the default one on the 1st pass of PCI address
allocation, even if it's occupied. This address gets picked
up by the second pass, and a conflict occurs:

XML error: Attempted double use of PCI slot 0000:00:02.0
(may need "multifunction='on'" for device on function 0)

Also fix the test that was supposed to catch this.
---
 src/qemu/qemu_command.c  | 50 +++++++++++++++++++++---------------------------
 tests/qemuxml2argvtest.c |  3 ++-
 2 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index d723dc8..2a64cd1 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2379,7 +2379,6 @@ qemuValidateDevicePCISlotsPIIX3(virDomainDefPtr def,
     size_t i;
     virDevicePCIAddress tmp_addr;
     bool qemuDeviceVideoUsable = virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
-    virDevicePCIAddressPtr addrptr;
     char *addrStr = NULL;
     qemuDomainPCIConnectFlags flags = QEMU_PCI_CONNECT_HOTPLUGGABLE | QEMU_PCI_CONNECT_TYPE_PCI;
 
@@ -2446,22 +2445,17 @@ qemuValidateDevicePCISlotsPIIX3(virDomainDefPtr def,
          */
         virDomainVideoDefPtr primaryVideo = def->videos[0];
         if (primaryVideo->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
-            primaryVideo->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
-            primaryVideo->info.addr.pci.domain = 0;
-            primaryVideo->info.addr.pci.bus = 0;
-            primaryVideo->info.addr.pci.slot = 2;
-            primaryVideo->info.addr.pci.function = 0;
-            addrptr = &primaryVideo->info.addr.pci;
-
-            if (!(addrStr = qemuDomainPCIAddressAsString(addrptr)))
+            memset(&tmp_addr, 0, sizeof(tmp_addr));
+            tmp_addr.slot = 2;
+
+            if (!(addrStr = qemuDomainPCIAddressAsString(&tmp_addr)))
                 goto cleanup;
-            if (!qemuDomainPCIAddressValidate(addrs, addrptr,
+            if (!qemuDomainPCIAddressValidate(addrs, &tmp_addr,
                                               addrStr, flags, false))
                 goto cleanup;
 
-            if (qemuDomainPCIAddressSlotInUse(addrs, addrptr)) {
+            if (qemuDomainPCIAddressSlotInUse(addrs, &tmp_addr)) {
                 if (qemuDeviceVideoUsable) {
-                    virResetLastError();
                     if (qemuDomainPCIAddressReserveNextSlot(addrs,
                                                             &primaryVideo->info,
                                                             flags) < 0)
@@ -2472,8 +2466,11 @@ qemuValidateDevicePCISlotsPIIX3(virDomainDefPtr def,
                                      "QEMU needs it for primary video"));
                     goto cleanup;
                 }
-            } else if (qemuDomainPCIAddressReserveSlot(addrs, addrptr, flags) < 0) {
-                goto cleanup;
+            } else {
+                if (qemuDomainPCIAddressReserveSlot(addrs, &tmp_addr, flags) < 0)
+                    goto cleanup;
+                primaryVideo->info.addr.pci = tmp_addr;
+                primaryVideo->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
             }
         } else if (!qemuDeviceVideoUsable) {
             if (primaryVideo->info.addr.pci.domain != 0 ||
@@ -2535,7 +2532,6 @@ qemuDomainValidateDevicePCISlotsQ35(virDomainDefPtr def,
     size_t i;
     virDevicePCIAddress tmp_addr;
     bool qemuDeviceVideoUsable = virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
-    virDevicePCIAddressPtr addrptr;
     char *addrStr = NULL;
     qemuDomainPCIConnectFlags flags = QEMU_PCI_CONNECT_TYPE_PCIE;
 
@@ -2619,22 +2615,17 @@ qemuDomainValidateDevicePCISlotsQ35(virDomainDefPtr def,
          */
         virDomainVideoDefPtr primaryVideo = def->videos[0];
         if (primaryVideo->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
-            primaryVideo->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
-            primaryVideo->info.addr.pci.domain = 0;
-            primaryVideo->info.addr.pci.bus = 0;
-            primaryVideo->info.addr.pci.slot = 1;
-            primaryVideo->info.addr.pci.function = 0;
-            addrptr = &primaryVideo->info.addr.pci;
-
-            if (!(addrStr = qemuDomainPCIAddressAsString(addrptr)))
+            memset(&tmp_addr, 0, sizeof(tmp_addr));
+            tmp_addr.slot = 1;
+
+            if (!(addrStr = qemuDomainPCIAddressAsString(&tmp_addr)))
                 goto cleanup;
-            if (!qemuDomainPCIAddressValidate(addrs, addrptr,
+            if (!qemuDomainPCIAddressValidate(addrs, &tmp_addr,
                                               addrStr, flags, false))
                 goto cleanup;
 
-            if (qemuDomainPCIAddressSlotInUse(addrs, addrptr)) {
+            if (qemuDomainPCIAddressSlotInUse(addrs, &tmp_addr)) {
                 if (qemuDeviceVideoUsable) {
-                    virResetLastError();
                     if (qemuDomainPCIAddressReserveNextSlot(addrs,
                                                             &primaryVideo->info,
                                                             flags) < 0)
@@ -2645,8 +2636,11 @@ qemuDomainValidateDevicePCISlotsQ35(virDomainDefPtr def,
                                      "QEMU needs it for primary video"));
                     goto cleanup;
                 }
-            } else if (qemuDomainPCIAddressReserveSlot(addrs, addrptr, flags) < 0) {
-                goto cleanup;
+            } else {
+                if (qemuDomainPCIAddressReserveSlot(addrs, &tmp_addr, flags) < 0)
+                    goto cleanup;
+                primaryVideo->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
+                primaryVideo->info.addr.pci = tmp_addr;
             }
         } else if (!qemuDeviceVideoUsable) {
             if (primaryVideo->info.addr.pci.domain != 0 ||
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 847e96f..5a2bfcc 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1193,7 +1193,8 @@ mymain(void)
     DO_TEST("video-device-pciaddr-default",
             QEMU_CAPS_KVM, QEMU_CAPS_VNC,
             QEMU_CAPS_DEVICE, QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
-            QEMU_CAPS_DEVICE_QXL, QEMU_CAPS_DEVICE_QXL_VGA);
+            QEMU_CAPS_DEVICE_QXL, QEMU_CAPS_DEVICE_QXL_VGA,
+            QEMU_CAPS_DEVICE_PCI_BRIDGE);
 
     DO_TEST("virtio-rng-default", QEMU_CAPS_DEVICE, QEMU_CAPS_DEVICE_VIRTIO_RNG,
             QEMU_CAPS_OBJECT_RNG_RANDOM);
-- 
1.8.3.2