qemu: format kernel_irqchip on the command line

Add kernel_irqchip=split/on to the QEMU command line
and a capability that looks for it in query-command-line-options
output. For the 'split' option, use a version check
since it cannot be reasonably probed.

https://bugzilla.redhat.com/show_bug.cgi?id=1427005

src/qemu/qemu_capabilities.c

@@ -366,6 +366,9 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "query-named-block-nodes",
               "cpu-cache",
               "qemu-xhci",
+
+              "kernel-irqchip", /* 255 */
+              "kernel-irqchip.split",
     );
 
 
@@ -3130,6 +3133,7 @@ static struct virQEMUCapsCommandLineProps virQEMUCapsCommandLine[] = {
     { "drive", "throttling.bps-total-max-length", QEMU_CAPS_DRIVE_IOTUNE_MAX_LENGTH },
     { "drive", "throttling.group", QEMU_CAPS_DRIVE_IOTUNE_GROUP },
     { "spice", "rendernode", QEMU_CAPS_SPICE_RENDERNODE },
+    { "machine", "kernel_irqchip", QEMU_CAPS_MACHINE_KERNEL_IRQCHIP },
 };
 
 static int
@@ -4742,6 +4746,10 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps,
     if (qemuCaps->version >= 2004050)
         virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACH_VIRT_GIC_VERSION);
 
+    /* no way to query if -machine kernel_irqchip supports split */
+    if (qemuCaps->version >= 2006000)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT);
+
     if (virQEMUCapsProbeQMPCommands(qemuCaps, mon) < 0)
         goto cleanup;
 

src/qemu/qemu_capabilities.h

@@ -404,6 +404,10 @@ typedef enum {
     QEMU_CAPS_CPU_CACHE, /* -cpu supports host-cache-info and l3-cache properties */
     QEMU_CAPS_DEVICE_QEMU_XHCI, /* -device qemu-xhci */
 
+    /* 255 */
+    QEMU_CAPS_MACHINE_KERNEL_IRQCHIP, /* -machine kernel_irqchip */
+    QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT, /* -machine kernel_irqchip=split */
+
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
 

src/qemu/qemu_command.c

@@ -7422,6 +7422,31 @@ qemuBuildMachineCommandLine(virCommandPtr cmd,
             }
         }
 
+        if (def->features[VIR_DOMAIN_FEATURE_IOAPIC] == VIR_TRISTATE_SWITCH_ON) {
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_KERNEL_IRQCHIP)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("I/O APIC tuning is not supported by this "
+                                 "QEMU binary"));
+                goto cleanup;
+            }
+            switch (def->ioapic) {
+            case VIR_DOMAIN_IOAPIC_QEMU:
+                if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT)) {
+                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                                   _("split I/O APIC is not supported by this "
+                                     "QEMU binary"));
+                    goto cleanup;
+                }
+                virBufferAddLit(&buf, ",kernel_irqchip=split");
+                break;
+            case VIR_DOMAIN_IOAPIC_KVM:
+                virBufferAddLit(&buf, ",kernel_irqchip=on");
+                break;
+            case VIR_DOMAIN_IOAPIC_LAST:
+                break;
+            }
+        }
+
         virCommandAddArgBuffer(cmd, &buf);
     }
 

src/qemu/qemu_domain.c

@@ -2806,6 +2806,22 @@ qemuDomainDefCPUPostParse(virDomainDefPtr def)
 }
 
 
+static int
+qemuDomainDefVerifyFeatures(const virDomainDef *def)
+{
+    if (def->features[VIR_DOMAIN_FEATURE_IOAPIC] == VIR_TRISTATE_SWITCH_ON &&
+        !ARCH_IS_X86(def->os.arch)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("I/O APIC tuning is not supported "
+                         "for '%s' architecture"),
+                       virArchToString(def->os.arch));
+        return -1;
+    }
+
+    return 0;
+}
+
+
 static int
 qemuDomainDefPostParse(virDomainDefPtr def,
                        virCapsPtr caps,
@@ -2861,6 +2877,9 @@ qemuDomainDefPostParse(virDomainDefPtr def,
 
     qemuDomainDefEnableDefaultFeatures(def, qemuCaps);
 
+    if (qemuDomainDefVerifyFeatures(def) < 0)
+        goto cleanup;
+
     if (qemuDomainRecheckInternalPaths(def, cfg, parseFlags) < 0)
         goto cleanup;
 

tests/qemucapabilitiesdata/caps_1.5.3.x86_64.xml

@@ -140,6 +140,7 @@
   <flag name='display'/>
   <flag name='vhost-scsi'/>
   <flag name='query-cpu-definitions'/>
+  <flag name='kernel-irqchip'/>
   <version>1005003</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_1.6.0.x86_64.xml

@@ -145,6 +145,7 @@
   <flag name='display'/>
   <flag name='vhost-scsi'/>
   <flag name='query-cpu-definitions'/>
+  <flag name='kernel-irqchip'/>
   <version>1006000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_1.7.0.x86_64.xml

@@ -147,6 +147,7 @@
   <flag name='display'/>
   <flag name='vhost-scsi'/>
   <flag name='query-cpu-definitions'/>
+  <flag name='kernel-irqchip'/>
   <version>1007000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.1.1.x86_64.xml

@@ -163,6 +163,7 @@
   <flag name='vhost-scsi'/>
   <flag name='query-cpu-definitions'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
   <version>2001001</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.4.0.x86_64.xml

@@ -185,6 +185,7 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
   <version>2004000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.5.0.x86_64.xml

@@ -191,6 +191,7 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
   <version>2005000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.6.0-gicv2.aarch64.xml

@@ -168,6 +168,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2006000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.6.0-gicv3.aarch64.xml

@@ -168,6 +168,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2006000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.6.0.ppc64le.xml

@@ -162,6 +162,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2006000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.6.0.x86_64.xml

@@ -200,6 +200,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2006000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml

@@ -130,6 +130,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2007000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml

@@ -202,6 +202,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2007000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.7.0)</package>

tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml

@@ -132,6 +132,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2007093</version>
   <kvmVersion>0</kvmVersion>
   <package></package>

tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml

@@ -203,6 +203,8 @@
   <flag name='query-cpu-definitions'/>
   <flag name='block-write-threshold'/>
   <flag name='query-named-block-nodes'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2008000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.8.0)</package>

tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml

@@ -210,6 +210,8 @@
   <flag name='query-named-block-nodes'/>
   <flag name='cpu-cache'/>
   <flag name='qemu-xhci'/>
+  <flag name='kernel-irqchip'/>
+  <flag name='kernel-irqchip.split'/>
   <version>2009000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.9.0)</package>

tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-ioapic.args

@@ -0,0 +1,19 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name QEMUGuest1 \
+-S \
+-machine q35,accel=kvm,kernel_irqchip=split \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-device intel-iommu

tests/qemuxml2argvtest.c

@@ -2509,6 +2509,11 @@ mymain(void)
     DO_TEST("intel-iommu-machine",
             QEMU_CAPS_MACHINE_OPT,
             QEMU_CAPS_MACHINE_IOMMU);
+    DO_TEST("intel-iommu-ioapic",
+            QEMU_CAPS_MACHINE_OPT,
+            QEMU_CAPS_MACHINE_KERNEL_IRQCHIP,
+            QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT,
+            QEMU_CAPS_DEVICE_INTEL_IOMMU);
 
     DO_TEST("cpu-hotplug-startup", QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS);