qemu: command: Remove fallback '-usb' handling

Currently all machine types which do honour '-usb' are already covered
by code which will either select a proper controller model or would
select the same one which '-usb' would use.

Thus all of the legacy -usb controller code can be removed.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>

src/qemu/qemu_command.c

@@ -2919,62 +2919,6 @@ qemuBuildControllerDevProps(const virDomainDef *domainDef,
 }
 
 
-static bool
-qemuBuildDomainForbidLegacyUSBController(const virDomainDef *def)
-{
-    if (ARCH_IS_X86(def->os.arch) ||
-        ARCH_IS_PPC(def->os.arch) ||
-        ARCH_IS_ARM(def->os.arch) ||
-        qemuDomainIsRISCVVirt(def))
-        return true;
-
-    return false;
-}
-
-
-static int
-qemuBuildLegacyUSBControllerCommandLine(virCommand *cmd,
-                                        const virDomainDef *def)
-{
-    size_t i;
-    size_t nlegacy = 0;
-    size_t nusb = 0;
-
-    for (i = 0; i < def->ncontrollers; i++) {
-        virDomainControllerDef *cont = def->controllers[i];
-
-        if (cont->type != VIR_DOMAIN_CONTROLLER_TYPE_USB)
-            continue;
-
-        /* If we have mode='none', there are no other USB controllers */
-        if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NONE)
-            return 0;
-
-        if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_DEFAULT)
-            nlegacy++;
-        else
-            nusb++;
-    }
-
-    if (nlegacy > 1) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("Multiple legacy USB controllers are not supported"));
-        return -1;
-    }
-
-    if (nusb == 0 &&
-        !qemuBuildDomainForbidLegacyUSBController(def) &&
-        !ARCH_IS_S390(def->os.arch)) {
-        /* We haven't added any USB controller yet, but we haven't been asked
-         * not to add one either. Add a legacy USB controller, unless we're
-         * creating a kind of guest we want to keep legacy-free */
-        virCommandAddArg(cmd, "-usb");
-    }
-
-    return 0;
-}
-
-
 /**
  * qemuBuildSkipController:
  * @controller: Controller to check
@@ -3055,28 +2999,15 @@ qemuBuildControllersByTypeCommandLine(virCommand *cmd,
         if (qemuBuildSkipController(cont, def))
             continue;
 
-        /* skip USB controllers with type none.*/
+        if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB) {
-        if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
+
-            cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NONE) {
+            /* skip USB controllers with type none*/
+            if (cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_NONE)
                 continue;
-        }
 
-        if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
+            /* skip 'default' controllers on s390 for legacy reasons */
-            cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_DEFAULT &&
+            if (ARCH_IS_S390(def->os.arch) &&
-            !qemuBuildDomainForbidLegacyUSBController(def)) {
+                cont->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_DEFAULT)
-
-            /* An appropriate default USB controller model should already
-             * have been selected in qemuDomainDeviceDefPostParse(); if
-             * we still have no model by now, we have to fall back to the
-             * legacy USB controller.
-             *
-             * Note that we *don't* want to end up with the legacy USB
-             * controller for q35 and virt machines, so we go ahead and
-             * fail in qemuBuildControllerDevProps(); on the other hand,
-             * for s390 machines we want to ignore any USB controller
-             * (see 548ba43028 for the full story), so we skip
-             * qemuBuildControllerDevProps() but we don't ultimately end
-             * up adding the legacy USB controller */
                 continue;
         }
 
@@ -3135,9 +3066,6 @@ qemuBuildControllersCommandLine(virCommand *cmd,
             return -1;
     }
 
-    if (qemuBuildLegacyUSBControllerCommandLine(cmd, def) < 0)
-        return -1;
-
     return 0;
 }
 

tests/qemuxmlconfdata/sparc-minimal.sparc-latest.args

@@ -24,7 +24,6 @@ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-redhat62sparc/.config \
 -rtc base=utc \
 -no-shutdown \
 -boot strict=on \
--usb \
 -blockdev '{"driver":"file","filename":"/home/berrange/VirtualMachines/redhat-6.2-sparc.img","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}' \
 -blockdev '{"node-name":"libvirt-2-format","read-only":false,"driver":"qcow2","file":"libvirt-2-storage"}' \
 -device scsi-hd,bus=scsi.0,scsi-id=0,device_id=drive-scsi0-0-0-0,drive=libvirt-2-format,id=scsi0-0-0-0,bootindex=1 \