qemu: fix handling of default/implicit devices for q35

This patch adds in special handling for a few devices that need to be
treated differently for q35 domains:

usb - there is no implicit/default usb controller for the q35
machinetype. This is done because normally the default usb controller
is added to a domain by just adding "-usb" to the qemu commandline,
and it's assumed that this will add a single piix3 usb1 controller at
slot 1 function 2. That's not what happens when the machinetype is
q35, though. Instead, adding -usb to the commandline adds 3 usb
(version 2) controllers to the domain at slot 0x1D.{1,2,7}. Rather
than having

  <controller type='usb' index='0'/>

translate into 3 separate devices on the PCI bus, it's cleaner to not
automatically add a default usb device; one can always be added
explicitly if desired. Or we may decide that on q35 machines, 3 usb
controllers will be automatically added when none is given. But for
this initial commit, at least we aren't locking ourselves into
something we later won't want.

video - qemu always initializes the primary video device immediately
after any integrated devices for the machinetype. Unless instructed
otherwise (by using "-device vga..." instead of "-vga" which libvirt
uses in many cases to work around deficiencies and bugs in various
qemu versions) qemu will always pick the first unused slot. In the
case of the "pc" machinetype and its derivatives, this is always slot
2, but on q35 machinetypes, the first free slot is slot 1 (since the
q35's integrated peripheral devices are placed in other slots,
e.g. slot 0x1f). In order to make the PCI address of the video device
predictable, that slot (1 or 2, depending on machinetype) is reserved
even when no video device has been specified.

sata - a q35 machine always has a sata controller implicitly added at
slot 0x1F, function 2. There is no way to avoid this controller, so we
always add it. Note that the xml2xml tests for the pcie-root and q35
cases were changed to use DO_TEST_DIFFERENT() so that we can check for
the sata controller being automatically added. This is especially
important because we can't check for it in the xml2argv output (it has
no effect on that output since it's an implicit device).

ide - q35 has no ide controllers.

isa and smbus controllers - these two are always present in a q35 (at
slot 0x1F functions 0 and 3) but we have no way of modelling them in
our config. We do need to reserve those functions so that the user
doesn't attempt to put anything else there though. (note that the "pc"
machine type also has an ISA controller, which we also ignore).

src/qemu/qemu_command.c

@@ -1686,6 +1686,18 @@ qemuCollectPCIAddress(virDomainDefPtr def ATTRIBUTE_UNUSED,
             break;
         }
     }
+    /* SATA controllers aren't hot-plugged, and can be put in either a
+     * PCI or PCIe slot
+     */
+    if (device->type == VIR_DOMAIN_DEVICE_CONTROLLER &&
+        device->data.controller->type == VIR_DOMAIN_CONTROLLER_TYPE_SATA)
+        flags = QEMU_PCI_CONNECT_TYPE_PCI | QEMU_PCI_CONNECT_TYPE_PCIE;
+
+    /* video cards aren't hot-plugged, and can be put in either a PCI
+     * or PCIe slot
+     */
+    if (device->type == VIR_DOMAIN_DEVICE_VIDEO)
+        flags = QEMU_PCI_CONNECT_TYPE_PCI | QEMU_PCI_CONNECT_TYPE_PCIE;
 
     /* Ignore implicit controllers on slot 0:0:1.0:
      * implicit IDE controller on 0:0:1.1 (no qemu command line)
@@ -2258,6 +2270,12 @@ qemuValidateDevicePCISlotsPIIX3(virDomainDefPtr def,
     }
 
     if (def->nvideos > 0) {
+        /* Because the PIIX3 integrated IDE/USB controllers are
+         * already at slot 1, when qemu looks for the first free slot
+         * to place the VGA controller (which is always the first
+         * device added after integrated devices), it *always* ends up
+         * at slot 2.
+         */
         virDomainVideoDefPtr primaryVideo = def->videos[0];
         if (primaryVideo->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
             primaryVideo->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
@@ -2318,6 +2336,136 @@ error:
 }
 
 
+static bool
+qemuDomainMachineIsQ35(virDomainDefPtr def)
+{
+    return (STRPREFIX(def->os.machine, "pc-q35") ||
+            STREQ(def->os.machine, "q35"));
+}
+
+
+static int
+qemuDomainValidateDevicePCISlotsQ35(virDomainDefPtr def,
+                                    virQEMUCapsPtr qemuCaps,
+                                    qemuDomainPCIAddressSetPtr addrs)
+{
+    size_t i;
+    virDevicePCIAddress tmp_addr;
+    bool qemuDeviceVideoUsable = virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
+    virDevicePCIAddressPtr addrptr;
+    qemuDomainPCIConnectFlags flags = QEMU_PCI_CONNECT_TYPE_PCIE;
+
+    /* Verify that the first SATA controller is at 00:1F.2 */
+    /* the q35 machine type *always* has a SATA controller at this address */
+    for (i = 0; i < def->ncontrollers; i++) {
+        if (def->controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_SATA &&
+            def->controllers[i]->idx == 0) {
+            if (def->controllers[i]->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
+                if (def->controllers[i]->info.addr.pci.domain != 0 ||
+                    def->controllers[i]->info.addr.pci.bus != 0 ||
+                    def->controllers[i]->info.addr.pci.slot != 0x1F ||
+                    def->controllers[i]->info.addr.pci.function != 2) {
+                    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                                   _("Primary SATA controller must have PCI address 0:0:1f.2"));
+                    goto error;
+                }
+            } else {
+                def->controllers[i]->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
+                def->controllers[i]->info.addr.pci.domain = 0;
+                def->controllers[i]->info.addr.pci.bus = 0;
+                def->controllers[i]->info.addr.pci.slot = 0x1F;
+                def->controllers[i]->info.addr.pci.function = 2;
+            }
+        }
+    }
+
+    /* Reserve slot 0x1F function 0 (ISA bridge, not in config model)
+     * and function 3 (SMBus, also not (yet) in config model). As with
+     * the SATA controller, these devices are always present in a q35
+     * machine; there is no way to not have them.
+     */
+    if (addrs->nbuses) {
+        memset(&tmp_addr, 0, sizeof(tmp_addr));
+        tmp_addr.slot = 0x1F;
+        tmp_addr.function = 0;
+        tmp_addr.multi = 1;
+        if (qemuDomainPCIAddressReserveAddr(addrs, &tmp_addr, flags,
+                                            false, false) < 0)
+           goto error;
+        tmp_addr.function = 3;
+        tmp_addr.multi = 0;
+        if (qemuDomainPCIAddressReserveAddr(addrs, &tmp_addr, flags,
+                                            false, false) < 0)
+           goto error;
+    }
+
+    if (def->nvideos > 0) {
+        /* NB: unlike the pc machinetypes, on q35 machinetypes the
+         * integrated devices are at slot 0x1f, so when qemu looks for
+         * the first free lot for the first VGA, it will always be at
+         * slot 1 (which was used up by the integrated PIIX3 devices
+         * on pc machinetypes).
+         */
+        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 (!qemuDomainPCIAddressValidate(addrs, addrptr, flags))
+                goto error;
+
+            if (qemuDomainPCIAddressSlotInUse(addrs, addrptr)) {
+                if (qemuDeviceVideoUsable) {
+                    virResetLastError();
+                    if (qemuDomainPCIAddressReserveNextSlot(addrs,
+                                                            &primaryVideo->info,
+                                                            flags) < 0)
+                        goto error;
+                } else {
+                    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                                   _("PCI address 0:0:1.0 is in use, "
+                                     "QEMU needs it for primary video"));
+                    goto error;
+                }
+            } else if (qemuDomainPCIAddressReserveSlot(addrs, addrptr, flags) < 0) {
+                goto error;
+            }
+        } else if (!qemuDeviceVideoUsable) {
+            if (primaryVideo->info.addr.pci.domain != 0 ||
+                primaryVideo->info.addr.pci.bus != 0 ||
+                primaryVideo->info.addr.pci.slot != 1 ||
+                primaryVideo->info.addr.pci.function != 0) {
+                virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                               _("Primary video card must have PCI address 0:0:1.0"));
+                goto error;
+            }
+            /* If TYPE==PCI, then qemuCollectPCIAddress() function
+             * has already reserved the address, so we must skip */
+        }
+    } else if (addrs->nbuses && !qemuDeviceVideoUsable) {
+        memset(&tmp_addr, 0, sizeof(tmp_addr));
+        tmp_addr.slot = 1;
+
+        if (qemuDomainPCIAddressSlotInUse(addrs, &tmp_addr)) {
+            VIR_DEBUG("PCI address 0:0:1.0 in use, future addition of a video"
+                      " device will not be possible without manual"
+                      " intervention");
+            virResetLastError();
+        } else if (qemuDomainPCIAddressReserveSlot(addrs, &tmp_addr, flags) < 0) {
+            goto error;
+        }
+    }
+    return 0;
+
+error:
+    return -1;
+}
+
+
 /*
  * This assigns static PCI slots to all configured devices.
  * The ordering here is chosen to match the ordering used
@@ -2368,6 +2516,11 @@ qemuAssignDevicePCISlots(virDomainDefPtr def,
         goto error;
     }
 
+    if (qemuDomainMachineIsQ35(def) &&
+        qemuDomainValidateDevicePCISlotsQ35(def, qemuCaps, addrs) < 0) {
+        goto error;
+    }
+
     /* PCI controllers */
     for (i = 0; i < def->ncontrollers; i++) {
         if (def->controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI) {
@@ -7679,6 +7832,9 @@ qemuBuildCommandLine(virConnectPtr conn,
                                        _("SATA is not supported with this "
                                          "QEMU binary"));
                         goto error;
+                    } else if (cont->idx == 0 && qemuDomainMachineIsQ35(def)) {
+                        /* first SATA controller on Q35 machines is implicit */
+                        continue;
                     } else {
                         char *devstr;
 
@@ -7692,6 +7848,7 @@ qemuBuildCommandLine(virConnectPtr conn,
                     }
                 } else if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
                            cont->model == -1 &&
+                           !qemuDomainMachineIsQ35(def) &&
                            (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_PIIX3_USB_UHCI) ||
                             def->os.arch == VIR_ARCH_PPC64)) {
                     if (usblegacy) {
@@ -7716,7 +7873,7 @@ qemuBuildCommandLine(virConnectPtr conn,
         }
     }
 
-    if (usbcontroller == 0)
+    if (usbcontroller == 0 && !qemuDomainMachineIsQ35(def))
         virCommandAddArg(cmd, "-usb");
 
     for (i = 0; i < def->nhubs; i++) {

src/qemu/qemu_domain.c

@@ -700,6 +700,7 @@ qemuDomainDefPostParse(virDomainDefPtr def,
                        void *opaque ATTRIBUTE_UNUSED)
 {
     bool addDefaultUSB = true;
+    bool addImplicitSATA = false;
     bool addPCIRoot = false;
     bool addPCIeRoot = false;
 
@@ -722,6 +723,7 @@ qemuDomainDefPostParse(virDomainDefPtr def,
             STREQ(def->os.machine, "q35")) {
            addPCIeRoot = true;
            addDefaultUSB = false;
+           addImplicitSATA = true;
            break;
         }
         if (!STRPREFIX(def->os.machine, "pc-0.") &&
@@ -754,6 +756,11 @@ qemuDomainDefPostParse(virDomainDefPtr def,
             def, VIR_DOMAIN_CONTROLLER_TYPE_USB, 0, -1) < 0)
         return -1;
 
+    if (addImplicitSATA &&
+        virDomainDefMaybeAddController(
+            def, VIR_DOMAIN_CONTROLLER_TYPE_SATA, 0, -1) < 0)
+        return -1;
+
     if (addPCIRoot &&
         virDomainDefMaybeAddController(
             def, VIR_DOMAIN_CONTROLLER_TYPE_PCI, 0,

tests/qemuxml2argvdata/qemuxml2argv-pcie-root.args

 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/libexec/qemu-kvm \
 -S -M q35 -m 2048 -smp 2 -nographic -nodefaults \
 -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c \
--device i82801b11-bridge,id=pci.1,bus=pci.0,addr=0x1 \
--device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1 -usb
+-device i82801b11-bridge,id=pci.1,bus=pci.0,addr=0x2 \
+-device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1

tests/qemuxml2argvdata/qemuxml2argv-pcie-root.xml

@@ -15,7 +15,6 @@
   <devices>
     <emulator>/usr/libexec/qemu-kvm</emulator>
     <controller type='pci' index='0' model='pcie-root'/>
-    <controller type='usb' index='0'/>
     <memballoon model='none'/>
   </devices>
 </domain>

tests/qemuxml2argvdata/qemuxml2argv-q35.args

 LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
 /usr/libexec/qemu-kvm -S -M q35 -m 2048 -smp 2 -nographic -nodefaults \
 -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c \
--device i82801b11-bridge,id=pci.1,bus=pci.0,addr=0x1 \
+-device i82801b11-bridge,id=pci.1,bus=pci.0,addr=0x2 \
 -device pci-bridge,chassis_nr=2,id=pci.2,bus=pci.1,addr=0x1 \
--usb \
 -vga qxl -global qxl.ram_size=67108864 -global qxl.vram_size=18874368

tests/qemuxml2argvtest.c

@@ -995,11 +995,13 @@ mymain(void)
     DO_TEST("pci-bridge-many-disks",
             QEMU_CAPS_DEVICE, QEMU_CAPS_DRIVE, QEMU_CAPS_DEVICE_PCI_BRIDGE);
     DO_TEST("pcie-root",
+            QEMU_CAPS_ICH9_AHCI,
             QEMU_CAPS_DEVICE, QEMU_CAPS_DEVICE_PCI_BRIDGE,
             QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE);
     DO_TEST("q35",
             QEMU_CAPS_DEVICE, QEMU_CAPS_DEVICE_PCI_BRIDGE,
             QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE,
+            QEMU_CAPS_ICH9_AHCI,
             QEMU_CAPS_VGA, QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
             QEMU_CAPS_VGA, QEMU_CAPS_VGA_QXL, QEMU_CAPS_DEVICE_QXL);
 

tests/qemuxml2xmloutdata/qemuxml2xmlout-pcie-root.xml

@@ -15,7 +15,7 @@
   <devices>
     <emulator>/usr/libexec/qemu-kvm</emulator>
     <controller type='pci' index='0' model='pcie-root'/>
-    <controller type='usb' index='0'/>
+    <controller type='sata' index='0'/>
     <controller type='pci' index='1' model='dmi-to-pci-bridge'/>
     <controller type='pci' index='2' model='pci-bridge'/>
     <memballoon model='none'/>

tests/qemuxml2xmloutdata/qemuxml2xmlout-q35.xml

+<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='dmi-to-pci-bridge'/>
+    <controller type='pci' index='2' model='pci-bridge'/>
+    <controller type='sata' index='0'/>
+    <video>
+      <model type='qxl' ram='65536' vram='18432' heads='1'/>
+    </video>
+    <memballoon model='none'/>
+  </devices>
+</domain>

tests/qemuxml2xmltest.c

@@ -295,7 +295,7 @@ mymain(void)
     DO_TEST_DIFFERENT("pci-autoadd-addr");
     DO_TEST_DIFFERENT("pci-autoadd-idx");
     DO_TEST_DIFFERENT("pcie-root");
-    DO_TEST("q35");
+    DO_TEST_DIFFERENT("q35");
 
     DO_TEST("hostdev-scsi-lsi");
     DO_TEST("hostdev-scsi-virtio-scsi");