[libvirt] [PATCH 1/3] qemu: add capability for vhost-net busy polling

[sferdjao at redhat.com]

From: Sahid Orentino Ferdjaoui <sahid.ferdjaoui at redhat.com>

QEMU 2.7.0 adds support of busy polling on vhost-net.

  69e87b32680a41d9761191443587c595b6f5fc3f

Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui at redhat.com>
---
 src/qemu/qemu_capabilities.c                     | 6 ++++++
 src/qemu/qemu_capabilities.h                     | 1 +
 tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml  | 1 +
 tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml | 1 +
 tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml  | 1 +
 tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml | 1 +
 tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml | 1 +
 7 files changed, 12 insertions(+)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index c0c39bd..faf6d82 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -376,6 +376,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "intel-iommu.device-iotlb", /* 260 */
               "virtio.iommu_platform",
               "virtio.ats",
+              "vhost-net.poll_us",
     );
 
 
@@ -4773,6 +4774,11 @@ virQEMUCapsInitQMPMonitor(virQEMUCapsPtr qemuCaps,
     if (qemuCaps->version >= 2006000)
         virQEMUCapsSet(qemuCaps, QEMU_CAPS_MACHINE_KERNEL_IRQCHIP_SPLIT);
 
+    /* Support for busy polling on vhost-net devices ("-netdev
+     * tap,...,poll-us=n") */
+    if (qemuCaps->version >= 2007000)
+        virQEMUCapsSet(qemuCaps, QEMU_CAPS_VHOST_NET_POLL_US);
+
     if (virQEMUCapsProbeQMPCommands(qemuCaps, mon) < 0)
         goto cleanup;
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index e57cae9..33f8ed0 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -415,6 +415,7 @@ typedef enum {
     QEMU_CAPS_INTEL_IOMMU_DEVICE_IOTLB, /* intel-iommu.device-iotlb */
     QEMU_CAPS_VIRTIO_PCI_IOMMU_PLATFORM, /* virtio-*-pci.iommu_platform */
     QEMU_CAPS_VIRTIO_PCI_ATS, /* virtio-*-pci.ats */
+    QEMU_CAPS_VHOST_NET_POLL_US, /* vhost-net with -netdev poll-us= */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml b/tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml
index 70cce64..f833d4a 100644
--- a/tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml
+++ b/tests/qemucapabilitiesdata/caps_2.7.0.s390x.xml
@@ -132,6 +132,7 @@
   <flag name='query-named-block-nodes'/>
   <flag name='kernel-irqchip'/>
   <flag name='kernel-irqchip.split'/>
+  <flag name='vhost-net.poll_us'/>
   <version>2007000</version>
   <kvmVersion>0</kvmVersion>
   <package></package>
diff --git a/tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml
index 49c0462..2ab44cf 100644
--- a/tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.7.0.x86_64.xml
@@ -205,6 +205,7 @@
   <flag name='kernel-irqchip'/>
   <flag name='kernel-irqchip.split'/>
   <flag name='intel-iommu.intremap'/>
+  <flag name='vhost-net.poll_us'/>
   <version>2007000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.7.0)</package>
diff --git a/tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml b/tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml
index 51be9bc..98f763d 100644
--- a/tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml
+++ b/tests/qemucapabilitiesdata/caps_2.8.0.s390x.xml
@@ -134,6 +134,7 @@
   <flag name='query-named-block-nodes'/>
   <flag name='kernel-irqchip'/>
   <flag name='kernel-irqchip.split'/>
+  <flag name='vhost-net.poll_us'/>
   <version>2007093</version>
   <kvmVersion>0</kvmVersion>
   <package></package>
diff --git a/tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml
index 01edbc8..bafe08f 100644
--- a/tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml
@@ -207,6 +207,7 @@
   <flag name='kernel-irqchip.split'/>
   <flag name='intel-iommu.intremap'/>
   <flag name='intel-iommu.eim'/>
+  <flag name='vhost-net.poll_us'/>
   <version>2008000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.8.0)</package>
diff --git a/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
index 58dd9f6..dc93b5a 100644
--- a/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
@@ -218,6 +218,7 @@
   <flag name='intel-iommu.device-iotlb'/>
   <flag name='virtio.iommu_platform'/>
   <flag name='virtio.ats'/>
+  <flag name='vhost-net.poll_us'/>
   <version>2009000</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.9.0)</package>
-- 
2.9.4