qemu: use virDomainPCIAddressSetAllMulti() to set multi when needed

If there are multiple devices assigned to the different functions of a
single PCI slot, they will not work properly if the device at function
0 doesn't have its "multi" attribute turned on, so it makes sense for
libvirt to turn it on during PCI address assignment. Setting multi
then assures that the new setting is stored in the config (so it will
be used next time the domain is started), preventing any potential
problems in the case that a future change in the configuration
eliminates the devices on all non-0 functions (multi will still be set
for function 0 even though it is the only function in use on the slot,
which has no useful purpose, but also doesn't cause any problems).

(NB: If we were to instead just decide on the setting for
multifunction at runtime, a later removal of the non-0 functions of a
slot would result in a silent change in the guest ABI for the
remaining device on function 0 (although it may seem like an
inconsequential guest ABI change, it *is* a guest ABI change to turn
off the multi bit).)

src/qemu/qemu_domain_address.c

@@ -2133,6 +2133,11 @@ qemuDomainAssignPCIAddresses(virDomainDefPtr def,
         if (qemuDomainAssignDevicePCISlots(def, qemuCaps, addrs) < 0)
             goto cleanup;
 
+        /* set multi attribute for devices at function 0 of
+         * any slot that has multiple functions in use
+         */
+        virDomainPCIAddressSetAllMulti(def);
+
         for (i = 0; i < def->ncontrollers; i++) {
             virDomainControllerDefPtr cont = def->controllers[i];
             int idx = cont->idx;

tests/qemuxml2argvdata/qemuxml2argv-q35-multifunction.args

@@ -0,0 +1,42 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/libexec/qemu-kvm \
+-name q35-test \
+-S \
+-M q35 \
+-m 2048 \
+-smp 2,sockets=2,cores=1,threads=1 \
+-uuid 11dbdcdd-4c3b-482b-8903-9bdb8c0a2774 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-q35-test/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-device ioh3420,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,\
+addr=0x2 \
+-device ioh3420,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 \
+-device ioh3420,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 \
+-device ioh3420,port=0x18,chassis=4,id=pci.4,bus=pcie.0,multifunction=on,\
+addr=0x3 \
+-device ioh3420,port=0x19,chassis=5,id=pci.5,bus=pcie.0,multifunction=on,\
+addr=0x3.0x1 \
+-device ioh3420,port=0x20,chassis=6,id=pci.6,bus=pcie.0,multifunction=off,\
+addr=0x4 \
+-device ioh3420,port=0x21,chassis=7,id=pci.7,bus=pcie.0,addr=0x4.0x1 \
+-device ioh3420,port=0x8,chassis=8,id=pci.8,bus=pcie.0,addr=0x1 \
+-device ioh3420,port=0x28,chassis=9,id=pci.9,bus=pcie.0,addr=0x5 \
+-device ioh3420,port=0x30,chassis=10,id=pci.10,bus=pcie.0,addr=0x6 \
+-device ioh3420,port=0x38,chassis=11,id=pci.11,bus=pcie.0,addr=0x7 \
+-device ioh3420,port=0x40,chassis=12,id=pci.12,bus=pcie.0,addr=0x8 \
+-device ioh3420,port=0x48,chassis=13,id=pci.13,bus=pcie.0,addr=0x9 \
+-device ioh3420,port=0x50,chassis=14,id=pci.14,bus=pcie.0,addr=0xa \
+-device ioh3420,port=0x58,chassis=15,id=pci.15,bus=pcie.0,addr=0xb \
+-device ioh3420,port=0x60,chassis=16,id=pci.16,bus=pcie.0,addr=0xc \
+-device ioh3420,port=0x68,chassis=17,id=pci.17,bus=pcie.0,addr=0xd \
+-device ioh3420,port=0x70,chassis=18,id=pci.18,bus=pcie.0,addr=0xe \
+-device nec-usb-xhci,id=usb,bus=pci.1,addr=0x0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.2,addr=0x0

tests/qemuxml2argvdata/qemuxml2argv-q35-multifunction.xml

@@ -0,0 +1,51 @@
+<domain type='qemu'>
+  <name>q35-test</name>
+  <uuid>11dbdcdd-4c3b-482b-8903-9bdb8c0a2774</uuid>
+  <memory unit='KiB'>2097152</memory>
+  <currentMemory unit='KiB'>2097152</currentMemory>
+  <vcpu placement='static' cpuset='0-1'>2</vcpu>
+  <os>
+    <type arch='x86_64' machine='q35'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/libexec/qemu-kvm</emulator>
+    <controller type='pci' model='pcie-root'/>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='2' function='0'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='2' function='1'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='2' function='2'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='3' function='0'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='3' function='1' multifunction='on'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='4' function='0' multifunction='off'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'>
+      <address type='pci' slot='4' function='1'/>
+    </controller>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+    <controller type='pci' model='pcie-root-port'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1938,6 +1938,29 @@ mymain(void)
             QEMU_CAPS_ICH9_USB_EHCI1,
             QEMU_CAPS_NEC_USB_XHCI,
             QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
+    DO_TEST("q35-multifunction",
+            QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY,
+            QEMU_CAPS_DEVICE_VIRTIO_RNG,
+            QEMU_CAPS_OBJECT_RNG_RANDOM,
+            QEMU_CAPS_NETDEV,
+            QEMU_CAPS_DEVICE_VIRTIO_NET,
+            QEMU_CAPS_DEVICE_VIRTIO_GPU,
+            QEMU_CAPS_VIRTIO_GPU_VIRGL,
+            QEMU_CAPS_VIRTIO_KEYBOARD,
+            QEMU_CAPS_VIRTIO_MOUSE,
+            QEMU_CAPS_VIRTIO_TABLET,
+            QEMU_CAPS_VIRTIO_INPUT_HOST,
+            QEMU_CAPS_VIRTIO_SCSI,
+            QEMU_CAPS_FSDEV,
+            QEMU_CAPS_FSDEV_WRITEOUT,
+            QEMU_CAPS_DEVICE_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_IOH3420,
+            QEMU_CAPS_ICH9_AHCI,
+            QEMU_CAPS_PCI_MULTIFUNCTION,
+            QEMU_CAPS_ICH9_USB_EHCI1,
+            QEMU_CAPS_NEC_USB_XHCI,
+            QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
     DO_TEST("q35-virt-manager-basic",
             QEMU_CAPS_KVM,
             QEMU_CAPS_RTC,

tests/qemuxml2xmloutdata/qemuxml2xmlout-q35-multifunction.xml

@@ -0,0 +1,120 @@
+<domain type='qemu'>
+  <name>q35-test</name>
+  <uuid>11dbdcdd-4c3b-482b-8903-9bdb8c0a2774</uuid>
+  <memory unit='KiB'>2097152</memory>
+  <currentMemory unit='KiB'>2097152</currentMemory>
+  <vcpu placement='static' cpuset='0-1'>2</vcpu>
+  <os>
+    <type arch='x86_64' machine='q35'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/libexec/qemu-kvm</emulator>
+    <controller type='pci' index='0' model='pcie-root'/>
+    <controller type='pci' index='1' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='1' port='0x10'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0' multifunction='on'/>
+    </controller>
+    <controller type='pci' index='2' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='2' port='0x11'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x1'/>
+    </controller>
+    <controller type='pci' index='3' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='3' port='0x12'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x2'/>
+    </controller>
+    <controller type='pci' index='4' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='4' port='0x18'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0' multifunction='on'/>
+    </controller>
+    <controller type='pci' index='5' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='5' port='0x19'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x1' multifunction='on'/>
+    </controller>
+    <controller type='pci' index='6' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='6' port='0x20'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='off'/>
+    </controller>
+    <controller type='pci' index='7' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='7' port='0x21'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x1'/>
+    </controller>
+    <controller type='pci' index='8' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='8' port='0x8'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
+    </controller>
+    <controller type='pci' index='9' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='9' port='0x28'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
+    </controller>
+    <controller type='pci' index='10' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='10' port='0x30'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
+    </controller>
+    <controller type='pci' index='11' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='11' port='0x38'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
+    </controller>
+    <controller type='pci' index='12' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='12' port='0x40'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
+    </controller>
+    <controller type='pci' index='13' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='13' port='0x48'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0'/>
+    </controller>
+    <controller type='pci' index='14' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='14' port='0x50'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
+    </controller>
+    <controller type='pci' index='15' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='15' port='0x58'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/>
+    </controller>
+    <controller type='pci' index='16' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='16' port='0x60'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0c' function='0x0'/>
+    </controller>
+    <controller type='pci' index='17' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='17' port='0x68'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0d' function='0x0'/>
+    </controller>
+    <controller type='pci' index='18' model='pcie-root-port'>
+      <model name='ioh3420'/>
+      <target chassis='18' port='0x70'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0e' function='0x0'/>
+    </controller>
+    <controller type='usb' index='0' model='nec-xhci'>
+      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
+    </controller>
+    <controller type='sata' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
+    </controller>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -795,6 +795,29 @@ mymain(void)
             QEMU_CAPS_ICH9_USB_EHCI1,
             QEMU_CAPS_NEC_USB_XHCI,
             QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
+    DO_TEST("q35-multifunction",
+            QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY,
+            QEMU_CAPS_DEVICE_VIRTIO_RNG,
+            QEMU_CAPS_OBJECT_RNG_RANDOM,
+            QEMU_CAPS_NETDEV,
+            QEMU_CAPS_DEVICE_VIRTIO_NET,
+            QEMU_CAPS_DEVICE_VIRTIO_GPU,
+            QEMU_CAPS_VIRTIO_GPU_VIRGL,
+            QEMU_CAPS_VIRTIO_KEYBOARD,
+            QEMU_CAPS_VIRTIO_MOUSE,
+            QEMU_CAPS_VIRTIO_TABLET,
+            QEMU_CAPS_VIRTIO_INPUT_HOST,
+            QEMU_CAPS_VIRTIO_SCSI,
+            QEMU_CAPS_FSDEV,
+            QEMU_CAPS_FSDEV_WRITEOUT,
+            QEMU_CAPS_DEVICE_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,
+            QEMU_CAPS_DEVICE_IOH3420,
+            QEMU_CAPS_ICH9_AHCI,
+            QEMU_CAPS_PCI_MULTIFUNCTION,
+            QEMU_CAPS_ICH9_USB_EHCI1,
+            QEMU_CAPS_NEC_USB_XHCI,
+            QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
     DO_TEST("q35-virt-manager-basic",
             QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY,
             QEMU_CAPS_DEVICE_VIRTIO_RNG,