qemu: Detect whether iothread polling is supported

Add a capability check for IOThread polling (all were added at the
same time, so only one check is necessary).

Based on code originally posted by Pavel Hrdina <phrdina@redhat.com>
with the only changes to include the more recent QEMU releases.

Signed-off-by: John Ferlan <jferlan@redhat.com>
ACKed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_capabilities.c

@@ -514,6 +514,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
 
               /* 320 */
               "memory-backend-memfd.hugetlb",
+              "iothread.poll-max-ns",
     );
 
 
@@ -1246,6 +1247,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = {
     { "nbd-server-start/arg-type/tls-creds", QEMU_CAPS_NBD_TLS },
     { "screendump/arg-type/device", QEMU_CAPS_SCREENDUMP_DEVICE },
     { "block-commit/arg-type/*top",  QEMU_CAPS_ACTIVE_COMMIT },
+    { "query-iothreads/ret-type/poll-max-ns", QEMU_CAPS_IOTHREAD_POLLING },
 };
 
 typedef struct _virQEMUCapsObjectTypeProps virQEMUCapsObjectTypeProps;

src/qemu/qemu_capabilities.h

@@ -498,6 +498,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
 
     /* 320 */
     QEMU_CAPS_OBJECT_MEMORY_MEMFD_HUGETLB, /* -object memory-backend-memfd.hugetlb */
+    QEMU_CAPS_IOTHREAD_POLLING, /* -object iothread.poll-max-ns */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;

tests/qemucapabilitiesdata/caps_2.10.0.aarch64.xml

@@ -151,6 +151,7 @@
   <flag name='blockdev-del'/>
   <flag name='vhost-vsock'/>
   <flag name='egl-headless'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2010000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>305067</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.10.0.ppc64.xml

@@ -150,6 +150,7 @@
   <flag name='blockdev-del'/>
   <flag name='vhost-vsock'/>
   <flag name='egl-headless'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2010000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>384412</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.10.0.s390x.xml

@@ -114,6 +114,7 @@
   <flag name='vhost-vsock'/>
   <flag name='egl-headless'/>
   <flag name='zpci'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2010000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>306247</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.10.0.x86_64.xml

@@ -192,6 +192,7 @@
   <flag name='vhost-vsock'/>
   <flag name='mch'/>
   <flag name='egl-headless'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2010000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>364386</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.11.0.s390x.xml

@@ -121,6 +121,7 @@
   <flag name='tpm-emulator'/>
   <flag name='egl-headless'/>
   <flag name='zpci'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2011000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>345099</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.11.0.x86_64.xml

@@ -198,6 +198,7 @@
   <flag name='mch'/>
   <flag name='mch.extended-tseg-mbytes'/>
   <flag name='egl-headless'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2011000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>368875</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.12.0.aarch64.xml

@@ -164,6 +164,7 @@
   <flag name='vfio-pci.display'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2011090</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>345725</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml

@@ -162,6 +162,7 @@
   <flag name='vfio-pci.display'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2011090</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>426509</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.12.0.s390x.xml

@@ -131,6 +131,7 @@
   <flag name='zpci'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2012000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>375102</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.12.0.x86_64.xml

@@ -205,6 +205,7 @@
   <flag name='vfio-pci.display'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2011090</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>414371</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.9.0.ppc64.xml

@@ -142,6 +142,7 @@
   <flag name='hda-output'/>
   <flag name='blockdev-del'/>
   <flag name='vhost-vsock'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2009000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>349056</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.9.0.s390x.xml

@@ -108,6 +108,7 @@
   <flag name='blockdev-del'/>
   <flag name='vhost-vsock'/>
   <flag name='zpci'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2009000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>267973</microcodeVersion>

tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml

@@ -186,6 +186,7 @@
   <flag name='vmgenid'/>
   <flag name='vhost-vsock'/>
   <flag name='mch'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2009000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>340375</microcodeVersion>

tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml

@@ -162,6 +162,7 @@
   <flag name='vfio-pci.display'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>2012050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>444946</microcodeVersion>

tests/qemucapabilitiesdata/caps_3.0.0.riscv32.xml

@@ -102,6 +102,7 @@
   <flag name='egl-headless'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>3000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>

tests/qemucapabilitiesdata/caps_3.0.0.riscv64.xml

@@ -102,6 +102,7 @@
   <flag name='egl-headless'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>3000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>0</microcodeVersion>

tests/qemucapabilitiesdata/caps_3.0.0.s390x.xml

@@ -133,6 +133,7 @@
   <flag name='zpci'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>3000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>388416</microcodeVersion>

tests/qemucapabilitiesdata/caps_3.0.0.x86_64.xml

@@ -207,6 +207,7 @@
   <flag name='vfio-pci.display'/>
   <flag name='memory-backend-memfd'/>
   <flag name='memory-backend-memfd.hugetlb'/>
+  <flag name='iothread.poll-max-ns'/>
   <version>3000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>425972</microcodeVersion>