qemu: Fix capabilities probing with TCG

Only probe QEMU binary with accel=tcg if TCG is not disabled.
Similarly, only add a VIR_DOMAIN_VIRT_QEMU guest if TCG
is available.
Signed-off-by: NTobin Feldman-Fitzthum <tobin@linux.vnet.ibm.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_capabilities.c

@@ -1021,13 +1021,16 @@ virQEMUCapsInitGuestFromBinary(virCapsPtr caps,
     virCapabilitiesAddGuestFeatureWithToggle(guest, VIR_CAPS_GUEST_FEATURE_TYPE_DISKSNAPSHOT,
                                              true, false);
 
-    if (virCapabilitiesAddGuestDomain(guest,
-                                      VIR_DOMAIN_VIRT_QEMU,
-                                      NULL,
-                                      NULL,
-                                      0,
-                                      NULL) == NULL)
-        goto cleanup;
+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG)) {
+        if (virCapabilitiesAddGuestDomain(guest,
+                                          VIR_DOMAIN_VIRT_QEMU,
+                                          NULL,
+                                          NULL,
+                                          0,
+                                          NULL) == NULL) {
+            goto cleanup;
+        }
+    }
 
     if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM)) {
         if (virCapabilitiesAddGuestDomain(guest,
@@ -2307,7 +2310,8 @@ bool
 virQEMUCapsIsVirtTypeSupported(virQEMUCapsPtr qemuCaps,
                                virDomainVirtType virtType)
 {
-    if (virtType == VIR_DOMAIN_VIRT_QEMU)
+    if (virtType == VIR_DOMAIN_VIRT_QEMU &&
+        virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG))
         return true;
 
     if (virtType == VIR_DOMAIN_VIRT_KVM &&
@@ -5166,6 +5170,7 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps,
      * off.
      */
     if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM) &&
+        virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG) &&
         virQEMUCapsInitQMPSingle(qemuCaps, libDir, runUid, runGid, true) < 0)
         return -1;