conf: qemu: add support for Hyper-V PV TLB flush

Qemu-3.0 supports Hyper-V-style PV TLB flush, Windows guests can benefit
from this feature as KVM knows which vCPUs are not currently scheduled (and
thus don't require any immediate action).
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>

docs/formatdomain.html.in

@@ -1976,6 +1976,7 @@
     <vendor_id state='on' value='KVM Hv'/>
     <frequencies state='on'/>
     <reenlightenment state='on'/>
+    <tlbflush state='on'/>
   </hyperv>
   <kvm>
     <hidden state='on'/>
@@ -2110,6 +2111,12 @@
           <td> on, off</td>
           <td><span class="since">4.7.0 (QEMU 3.0)</span></td>
         </tr>
+        <tr>
+          <td>tlbflush</td>
+          <td>Enable PV TLB flush support</td>
+          <td> on, off</td>
+          <td><span class="since">4.7.0 (QEMU 3.0)</span></td>
+        </tr>
       </table>
       </dd>
       <dt><code>pvspinlock</code></dt>

docs/schemas/domaincommon.rng

@@ -5743,6 +5743,11 @@
             <ref name="featurestate"/>
           </element>
         </optional>
+        <optional>
+          <element name="tlbflush">
+            <ref name="featurestate"/>
+          </element>
+        </optional>
       </interleave>
     </element>
   </define>

src/conf/domain_conf.c

@@ -171,7 +171,8 @@ VIR_ENUM_IMPL(virDomainHyperv, VIR_DOMAIN_HYPERV_LAST,
               "reset",
               "vendor_id",
               "frequencies",
-              "reenlightenment")
+              "reenlightenment",
+              "tlbflush")
 
 VIR_ENUM_IMPL(virDomainKVM, VIR_DOMAIN_KVM_LAST,
               "hidden")
@@ -20282,6 +20283,7 @@ virDomainDefParseXML(xmlDocPtr xml,
             case VIR_DOMAIN_HYPERV_RESET:
             case VIR_DOMAIN_HYPERV_FREQUENCIES:
             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+            case VIR_DOMAIN_HYPERV_TLBFLUSH:
                 break;
 
             case VIR_DOMAIN_HYPERV_SPINLOCKS:
@@ -22468,6 +22470,7 @@ virDomainDefFeaturesCheckABIStability(virDomainDefPtr src,
             case VIR_DOMAIN_HYPERV_RESET:
             case VIR_DOMAIN_HYPERV_FREQUENCIES:
             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+            case VIR_DOMAIN_HYPERV_TLBFLUSH:
                 if (src->hyperv_features[i] != dst->hyperv_features[i]) {
                     virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                    _("State of HyperV enlightenment "
@@ -28185,6 +28188,7 @@ virDomainDefFormatInternal(virDomainDefPtr def,
                     case VIR_DOMAIN_HYPERV_RESET:
                     case VIR_DOMAIN_HYPERV_FREQUENCIES:
                     case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+                    case VIR_DOMAIN_HYPERV_TLBFLUSH:
                         break;
 
                     case VIR_DOMAIN_HYPERV_SPINLOCKS:

src/conf/domain_conf.h

@@ -1793,6 +1793,7 @@ typedef enum {
     VIR_DOMAIN_HYPERV_VENDOR_ID,
     VIR_DOMAIN_HYPERV_FREQUENCIES,
     VIR_DOMAIN_HYPERV_REENLIGHTENMENT,
+    VIR_DOMAIN_HYPERV_TLBFLUSH,
 
     VIR_DOMAIN_HYPERV_LAST
 } virDomainHyperv;

src/cpu/cpu_x86.c

@@ -113,6 +113,8 @@ KVM_FEATURE_DEF(VIR_CPU_x86_KVM_HV_FREQUENCIES,
                 0x40000003, 0x00000800);
 KVM_FEATURE_DEF(VIR_CPU_x86_KVM_HV_REENLIGHTENMENT,
                 0x40000003, 0x00002000);
+KVM_FEATURE_DEF(VIR_CPU_x86_KVM_HV_TLBFLUSH,
+                0x40000004, 0x00000004);
 
 static virCPUx86Feature x86_kvm_features[] =
 {
@@ -135,6 +137,7 @@ static virCPUx86Feature x86_kvm_features[] =
     KVM_FEATURE(VIR_CPU_x86_KVM_HV_RESET),
     KVM_FEATURE(VIR_CPU_x86_KVM_HV_FREQUENCIES),
     KVM_FEATURE(VIR_CPU_x86_KVM_HV_REENLIGHTENMENT),
+    KVM_FEATURE(VIR_CPU_x86_KVM_HV_TLBFLUSH),
 };
 
 typedef struct _virCPUx86Model virCPUx86Model;

src/cpu/cpu_x86_data.h

@@ -65,6 +65,7 @@ struct _virCPUx86CPUID {
 # define VIR_CPU_x86_KVM_HV_RESET     "__kvm_hv_reset"
 # define VIR_CPU_x86_KVM_HV_FREQUENCIES "__kvm_hv_frequencies"
 # define VIR_CPU_x86_KVM_HV_REENLIGHTENMENT "__kvm_hv_reenlightenment"
+# define VIR_CPU_x86_KVM_HV_TLBFLUSH  "__kvm_hv_tlbflush"
 
 
 # define VIR_CPU_X86_DATA_INIT { 0 }

src/qemu/qemu_command.c

@@ -6868,6 +6868,7 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
             case VIR_DOMAIN_HYPERV_RESET:
             case VIR_DOMAIN_HYPERV_FREQUENCIES:
             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+            case VIR_DOMAIN_HYPERV_TLBFLUSH:
                 if (def->hyperv_features[i] == VIR_TRISTATE_SWITCH_ON)
                     virBufferAsprintf(&buf, ",hv_%s",
                                       virDomainHypervTypeToString(i));

src/qemu/qemu_parse_command.c

@@ -1538,6 +1538,7 @@ qemuParseCommandLineCPU(virDomainDefPtr dom,
             case VIR_DOMAIN_HYPERV_RESET:
             case VIR_DOMAIN_HYPERV_FREQUENCIES:
             case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+            case VIR_DOMAIN_HYPERV_TLBFLUSH:
                 if (value) {
                     virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                    _("HyperV feature '%s' should not "

src/qemu/qemu_process.c

@@ -3914,6 +3914,7 @@ qemuProcessVerifyHypervFeatures(virDomainDefPtr def,
         case VIR_DOMAIN_HYPERV_RESET:
         case VIR_DOMAIN_HYPERV_FREQUENCIES:
         case VIR_DOMAIN_HYPERV_REENLIGHTENMENT:
+        case VIR_DOMAIN_HYPERV_TLBFLUSH:
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                            _("host doesn't support hyperv '%s' feature"),
                            virDomainHypervTypeToString(i));

tests/qemuxml2argvdata/hyperv-off.xml

@@ -22,6 +22,7 @@
       <vendor_id state='off'/>
       <frequencies state='off'/>
       <reenlightenment state='off'/>
+      <tlbflush state='off'/>
     </hyperv>
   </features>
   <clock offset='utc'/>

tests/qemuxml2argvdata/hyperv.args

@@ -10,7 +10,7 @@ QEMU_AUDIO_DRV=none \
 -machine pc,accel=tcg,usb=off,dump-guest-core=off \
 -cpu 'qemu32,hv_relaxed,hv_vapic,hv_spinlocks=0x2fff,hv_vpindex,hv_runtime,\
 hv_synic,hv_stimer,hv_reset,hv_vendor_id=KVM Hv,hv_frequencies,\
-hv_reenlightenment' \
+hv_reenlightenment,hv_tlbflush' \
 -m 214 \
 -smp 6,sockets=6,cores=1,threads=1 \
 -uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \

tests/qemuxml2argvdata/hyperv.xml

@@ -22,6 +22,7 @@
       <vendor_id state='on' value='KVM Hv'/>
       <frequencies state='on'/>
       <reenlightenment state='on'/>
+      <tlbflush state='on'/>
     </hyperv>
   </features>
   <clock offset='utc'/>

tests/qemuxml2xmloutdata/hyperv-off.xml

@@ -22,6 +22,7 @@
       <vendor_id state='off'/>
       <frequencies state='off'/>
       <reenlightenment state='off'/>
+      <tlbflush state='off'/>
     </hyperv>
   </features>
   <clock offset='utc'/>

tests/qemuxml2xmloutdata/hyperv.xml

@@ -22,6 +22,7 @@
       <vendor_id state='on' value='KVM Hv'/>
       <frequencies state='on'/>
       <reenlightenment state='on'/>
+      <tlbflush state='on'/>
     </hyperv>
   </features>
   <clock offset='utc'/>