[libvirt] [PATCH v3] Add support for virtio-net.tx_queue_size

Michal Privoznik mprivozn at redhat.com
Wed Aug 2 10:44:37 UTC 2017


https://bugzilla.redhat.com/show_bug.cgi?id=1462653

Just like I've added support for setting rx_queue_size (in
c56cdf259 and friends), qemu just gained support for setting tx
ring size.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---

diff to v2:
- rebase to current HEAD

There's no fundamental change since v1. It's just discussion on this patch that
makes me send newer versions because the older ones do not apply cleanly
anymore.

 docs/formatdomain.html.in                                | 16 +++++++++++++++-
 docs/schemas/domaincommon.rng                            |  5 +++++
 src/conf/domain_conf.c                                   | 16 ++++++++++++++++
 src/conf/domain_conf.h                                   |  1 +
 src/qemu/qemu_capabilities.c                             |  4 +++-
 src/qemu/qemu_capabilities.h                             |  1 +
 src/qemu/qemu_command.c                                  |  8 ++++++++
 src/qemu/qemu_domain.c                                   | 16 +++++++++++-----
 ...e.args => qemuxml2argv-net-virtio-rxtxqueuesize.args} |  4 ++--
 ...ize.xml => qemuxml2argv-net-virtio-rxtxqueuesize.xml} |  2 +-
 tests/qemuxml2argvtest.c                                 |  5 +++--
 ...e.xml => qemuxml2xmlout-net-virtio-rxtxqueuesize.xml} |  2 +-
 tests/qemuxml2xmltest.c                                  |  2 +-
 13 files changed, 68 insertions(+), 14 deletions(-)
 rename tests/qemuxml2argvdata/{qemuxml2argv-net-virtio-rxqueuesize.args => qemuxml2argv-net-virtio-rxtxqueuesize.args} (85%)
 rename tests/qemuxml2argvdata/{qemuxml2argv-net-virtio-rxqueuesize.xml => qemuxml2argv-net-virtio-rxtxqueuesize.xml} (93%)
 rename tests/qemuxml2xmloutdata/{qemuxml2xmlout-net-virtio-rxqueuesize.xml => qemuxml2xmlout-net-virtio-rxtxqueuesize.xml} (96%)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 91195be0b..47e21c10d 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -5074,7 +5074,7 @@ qemu-kvm -net nic,model=? /dev/null
     <source network='default'/>
     <target dev='vnet1'/>
     <model type='virtio'/>
-    <b><driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256'>
+    <b><driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256' tx_queue_size='256'>
       <host csum='off' gso='off' tso4='off' tso6='off' ecn='off' ufo='off' mrg_rxbuf='off'/>
       <guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/>
     </driver>
@@ -5204,6 +5204,20 @@ qemu-kvm -net nic,model=? /dev/null
         <b>In general you should leave this option alone, unless you
         are very certain you know what you are doing.</b>
       </dd>
+      <dt><code>tx_queue_size</code></dt>
+      <dd>
+        The optional <code>tx_queue_size</code> attribute controls
+        the size of virtio ring for each queue as described above.
+        The default value is hypervisor dependent and may change
+        across its releases. Moreover, some hypervisors may pose
+        some restrictions on actual value. For instance, latest
+        QEMU (as of 2017-07-13) requires value to be a power of two
+        from [256, 1024] range.
+        <span class="since">Since 3.6.0 (QEMU and KVM only)</span><br/><br/>
+
+        <b>In general you should leave this option alone, unless you
+        are very certain you know what you are doing.</b>
+      </dd>
       <dt>virtio options</dt>
       <dd>
         For virtio interfaces,
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index a49ce9303..3f56d8f45 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -2711,6 +2711,11 @@
                   <ref name='positiveInteger'/>
                 </attribute>
               </optional>
+              <optional>
+                <attribute name='tx_queue_size'>
+                  <ref name='positiveInteger'/>
+                </attribute>
+              </optional>
               <optional>
                 <attribute name="txmode">
                   <choice>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 34c8f45ed..c3a167576 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -9833,6 +9833,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     char *event_idx = NULL;
     char *queues = NULL;
     char *rx_queue_size = NULL;
+    char *tx_queue_size = NULL;
     char *str = NULL;
     char *filter = NULL;
     char *internal = NULL;
@@ -10006,6 +10007,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
                 event_idx = virXMLPropString(cur, "event_idx");
                 queues = virXMLPropString(cur, "queues");
                 rx_queue_size = virXMLPropString(cur, "rx_queue_size");
+                tx_queue_size = virXMLPropString(cur, "tx_queue_size");
             } else if (xmlStrEqual(cur->name, BAD_CAST "filterref")) {
                 if (filter) {
                     virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -10403,6 +10405,16 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
             }
             def->driver.virtio.rx_queue_size = q;
         }
+        if (tx_queue_size) {
+            unsigned int q;
+            if (virStrToLong_uip(tx_queue_size, NULL, 10, &q) < 0) {
+                virReportError(VIR_ERR_XML_DETAIL,
+                               _("'tx_queue_size' attribute must be positive number: %s"),
+                               tx_queue_size);
+                goto error;
+            }
+            def->driver.virtio.tx_queue_size = q;
+        }
         if ((str = virXPathString("string(./driver/host/@csum)", ctxt))) {
             if ((val = virTristateSwitchTypeFromString(str)) <= 0) {
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -10600,6 +10612,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
     VIR_FREE(event_idx);
     VIR_FREE(queues);
     VIR_FREE(rx_queue_size);
+    VIR_FREE(tx_queue_size);
     VIR_FREE(str);
     VIR_FREE(filter);
     VIR_FREE(type);
@@ -22497,6 +22510,9 @@ virDomainVirtioNetDriverFormat(char **outstr,
     if (def->driver.virtio.rx_queue_size)
         virBufferAsprintf(&buf, " rx_queue_size='%u'",
                           def->driver.virtio.rx_queue_size);
+    if (def->driver.virtio.tx_queue_size)
+        virBufferAsprintf(&buf, " tx_queue_size='%u'",
+                          def->driver.virtio.tx_queue_size);
 
     virDomainVirtioOptionsFormat(&buf, def->virtio);
 
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 239b21813..f857f509e 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -969,6 +969,7 @@ struct _virDomainNetDef {
             virTristateSwitch event_idx;
             unsigned int queues; /* Multiqueue virtio-net */
             unsigned int rx_queue_size;
+            unsigned int tx_queue_size;
             struct {
                 virTristateSwitch csum;
                 virTristateSwitch gso;
diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index afe70d00d..e61d2f7b0 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -435,7 +435,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
 
               /* 265 */
               "spapr-pci-host-bridge.numa_node",
-              "vnc-multi-servers"
+              "vnc-multi-servers",
+              "virtio-net.tx_queue_size",
     );
 
 
@@ -1705,6 +1706,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsVirtioNet[] = {
     { "tx", QEMU_CAPS_VIRTIO_TX_ALG },
     { "event_idx", QEMU_CAPS_VIRTIO_NET_EVENT_IDX },
     { "rx_queue_size", QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE },
+    { "tx_queue_size", QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE },
     { "host_mtu", QEMU_CAPS_VIRTIO_NET_HOST_MTU },
 };
 
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 8b856e1b2..8804cc781 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -422,6 +422,7 @@ typedef enum {
     /* 265 */
     QEMU_CAPS_SPAPR_PCI_HOST_BRIDGE_NUMA_NODE, /* spapr-pci-host-bridge.numa_node= */
     QEMU_CAPS_VNC_MULTI_SERVERS, /* -vnc vnc=unix:/path */
+    QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE, /* virtio-net-*.tx_queue_size */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index d1f5c3642..da6ddff6c 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3725,6 +3725,14 @@ qemuBuildNicDevStr(virDomainDefPtr def,
         }
         virBufferAsprintf(&buf, ",rx_queue_size=%u", net->driver.virtio.rx_queue_size);
     }
+    if (usingVirtio && net->driver.virtio.tx_queue_size) {
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("virtio tx_queue_size option is not supported with this QEMU binary"));
+            goto error;
+        }
+        virBufferAsprintf(&buf, ",tx_queue_size=%u", net->driver.virtio.tx_queue_size);
+    }
 
     if (usingVirtio && net->mtu) {
         if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_NET_HOST_MTU)) {
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 6fe9aa855..fe27e1122 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -3226,11 +3226,17 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
             goto cleanup;
         }
 
-        if (STREQ_NULLABLE(net->model, "virtio") &&
-            net->driver.virtio.rx_queue_size & (net->driver.virtio.rx_queue_size - 1)) {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                           _("rx_queue_size has to be a power of two"));
-            goto cleanup;
+        if (STREQ_NULLABLE(net->model, "virtio")) {
+            if (net->driver.virtio.rx_queue_size & (net->driver.virtio.rx_queue_size - 1)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("rx_queue_size has to be a power of two"));
+                goto cleanup;
+            }
+            if (net->driver.virtio.tx_queue_size & (net->driver.virtio.tx_queue_size - 1)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("tx_queue_size has to be a power of two"));
+                goto cleanup;
+            }
         }
 
         if (net->mtu &&
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.args b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.args
similarity index 85%
rename from tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.args
rename to tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.args
index 07c358a02..c78da3d17 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.args
@@ -21,7 +21,7 @@ server,nowait \
 -usb \
 -drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-ide0-0-0 \
 -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
--device virtio-net-pci,rx_queue_size=512,vlan=0,id=net0,mac=00:11:22:33:44:55,\
-bus=pci.0,addr=0x3 \
+-device virtio-net-pci,rx_queue_size=512,tx_queue_size=1024,vlan=0,id=net0,\
+mac=00:11:22:33:44:55,bus=pci.0,addr=0x3 \
 -net user,vlan=0,name=hostnet0 \
 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.xml
similarity index 93%
rename from tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.xml
rename to tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.xml
index d64e31df2..b51931d52 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxqueuesize.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-rxtxqueuesize.xml
@@ -22,7 +22,7 @@
     <interface type='user'>
       <mac address='00:11:22:33:44:55'/>
       <model type='virtio'/>
-      <driver rx_queue_size='512'/>
+      <driver rx_queue_size='512' tx_queue_size='1024'/>
     </interface>
     <memballoon model='virtio'/>
   </devices>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index c2c1767c7..aa83013a2 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1167,8 +1167,9 @@ mymain(void)
             QEMU_CAPS_VIRTIO_S390);
     DO_TEST("net-virtio-ccw",
             QEMU_CAPS_VIRTIO_CCW, QEMU_CAPS_VIRTIO_S390);
-    DO_TEST("net-virtio-rxqueuesize",
-            QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE);
+    DO_TEST("net-virtio-rxtxqueuesize",
+            QEMU_CAPS_VIRTIO_NET_RX_QUEUE_SIZE,
+            QEMU_CAPS_VIRTIO_NET_TX_QUEUE_SIZE);
     DO_TEST_PARSE_ERROR("net-virtio-rxqueuesize-invalid-size", NONE);
     DO_TEST("net-eth", NONE);
     DO_TEST("net-eth-ifname", NONE);
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxqueuesize.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxtxqueuesize.xml
similarity index 96%
rename from tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxqueuesize.xml
rename to tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxtxqueuesize.xml
index 78433026c..5c33a58ad 100644
--- a/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxqueuesize.xml
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-rxtxqueuesize.xml
@@ -29,7 +29,7 @@
     <interface type='user'>
       <mac address='00:11:22:33:44:55'/>
       <model type='virtio'/>
-      <driver rx_queue_size='512'/>
+      <driver rx_queue_size='512' tx_queue_size='1024'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
     </interface>
     <input type='mouse' bus='ps2'/>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 5b47b0711..bf4d507f6 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -537,7 +537,7 @@ mymain(void)
     DO_TEST("net-eth-ifname", NONE);
     DO_TEST("net-eth-hostip", NONE);
     DO_TEST("net-virtio-network-portgroup", NONE);
-    DO_TEST("net-virtio-rxqueuesize", NONE);
+    DO_TEST("net-virtio-rxtxqueuesize", NONE);
     DO_TEST("net-hostdev", NONE);
     DO_TEST("net-hostdev-vfio", NONE);
     DO_TEST("net-midonet", NONE);
-- 
2.13.0




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