When a domain vNIC's bandwidth is to be changed (at runtime) it is
possible that guaranteed minimal bandwidth (@floor) will change too.
Well, so far it is, because we still don't have an implementation that
allows setting it dynamically, so it's effectively erased on:
#virsh domiftune $dom vnet0 --inbound 0
However, that's slightly unfortunate. We do some checks on domain
startup to see if @floor can be guaranteed. We ought do the same if
QoS is changed at runtime.
Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
src/network/bridge_driver.c | 72 +++++++++++++++++++++++++++++++++++++++++++--
src/network/bridge_driver.h | 12 ++++++++
2 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 17fc430..fa60ba4 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -4686,9 +4686,18 @@ networkGetNetworkAddress(const char *netname, char **netaddr)
* networkCheckBandwidth:
* @net: network QoS
* @ifaceBand: interface QoS (may be NULL if no QoS)
+ * @oldBandwidth: new interface QoS (may be NULL if no QoS)
* @ifaceMac: interface MAC (used in error messages for identification)
* @new_rate: new rate for non guaranteed class
*
+ * Function checks if @ifaceBand can be satisfied on @net. However, sometimes it
+ * may happen that the interface that @ifaceBand corresponds to is already
+ * plugged into the @net and the bandwidth is to be updated. In that case we
+ * need to check if new bandwidth can be satisfied. If that's the case
+ * @ifaceBand should point to new bandwidth settings and @oldBandwidth to
+ * current ones. If you want to suppress this functionality just pass
+ * @oldBandwidth == NULL.
+ *
* Returns: -1 if plugging would overcommit network QoS
* 0 if plugging is safe (@new_rate updated)
* 1 if no QoS is set (@new_rate untouched)
@@ -4696,6 +4705,7 @@ networkGetNetworkAddress(const char *netname, char **netaddr)
static int
networkCheckBandwidth(virNetworkObjPtr net,
virNetDevBandwidthPtr ifaceBand,
+ virNetDevBandwidthPtr oldBandwidth,
virMacAddr ifaceMac,
unsigned long long *new_rate)
{
@@ -4723,6 +4733,8 @@ networkCheckBandwidth(virNetworkObjPtr net,
}
tmp_new_rate = netBand->in->average;
+ if (oldBandwidth && oldBandwidth->in)
+ tmp_floor_sum -= oldBandwidth->in->floor;
tmp_floor_sum += ifaceBand->in->floor;
/* check against peak */
@@ -4749,7 +4761,8 @@ networkCheckBandwidth(virNetworkObjPtr net,
goto cleanup;
}
- *new_rate = tmp_new_rate;
+ if (new_rate)
+ *new_rate = tmp_new_rate;
ret = 0;
cleanup:
@@ -4791,7 +4804,7 @@ networkPlugBandwidth(virNetworkObjPtr net,
char ifmac[VIR_MAC_STRING_BUFLEN];
virNetDevBandwidthPtr ifaceBand = virDomainNetGetActualBandwidth(iface);
- if ((plug_ret = networkCheckBandwidth(net, ifaceBand,
+ if ((plug_ret = networkCheckBandwidth(net, ifaceBand, NULL,
iface->mac, &new_rate)) < 0) {
/* helper reported error */
goto cleanup;
@@ -4917,3 +4930,58 @@ networkNetworkObjTaint(virNetworkObjPtr net,
virNetworkTaintTypeToString(taint));
}
}
+
+
+static bool
+networkBandwidthGenericChecks(virDomainNetDefPtr iface,
+ virNetDevBandwidthPtr newBandwidth)
+{
+ virNetDevBandwidthPtr ifaceBand = virDomainNetGetActualBandwidth(iface);
+ unsigned long long old_floor, new_floor;
+
+ if (virDomainNetGetActualType(iface) != VIR_DOMAIN_NET_TYPE_NETWORK) {
+ /* This is not an interface that's plugged into a network.
+ * We don't care. Thus from our POV bandwidth change is allowed. */
+ return false;
+ }
+
+ old_floor = new_floor = 0;
+
+ if (ifaceBand && ifaceBand->in)
+ old_floor = ifaceBand->in->floor;
+ if (newBandwidth && newBandwidth->in)
+ new_floor = newBandwidth->in->floor;
+
+ return new_floor != old_floor;
+}
+
+
+bool
+networkBandwidthChangeAllowed(virDomainNetDefPtr iface,
+ virNetDevBandwidthPtr newBandwidth)
+{
+ virNetworkDriverStatePtr driver = networkGetDriver();
+ virNetworkObjPtr network = NULL;
+ virNetDevBandwidthPtr ifaceBand = virDomainNetGetActualBandwidth(iface);
+ bool ret = false;
+
+ if (!networkBandwidthGenericChecks(iface, newBandwidth))
+ return true;
+
+ network = virNetworkObjFindByName(driver->networks, iface->data.network.name);
+ if (!network) {
+ virReportError(VIR_ERR_NO_NETWORK,
+ _("no network with matching name '%s'"),
+ iface->data.network.name);
+ return false;
+ }
+
+ if (networkCheckBandwidth(network, newBandwidth, ifaceBand, iface->mac, NULL) < 0)
+ goto cleanup;
+
+ ret = true;
+
+ cleanup:
+ virNetworkObjEndAPI(&network);
+ return ret;
+}
diff --git a/src/network/bridge_driver.h b/src/network/bridge_driver.h
index 513ccf7..cce9237 100644
--- a/src/network/bridge_driver.h
+++ b/src/network/bridge_driver.h
@@ -52,6 +52,11 @@ int networkDnsmasqConfContents(virNetworkObjPtr network,
char **configstr,
dnsmasqContext *dctx,
dnsmasqCapsPtr caps);
+
+bool networkBandwidthChangeAllowed(virDomainNetDefPtr iface,
+ virNetDevBandwidthPtr newBandwidth)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
# else
/* Define no-op replacements that don't drag in any link dependencies. */
# define networkAllocateActualDevice(dom, iface) 0
@@ -73,6 +78,13 @@ networkReleaseActualDevice(virDomainDefPtr dom ATTRIBUTE_UNUSED,
return 0;
}
+static inline bool
+networkBandwidthChangeAllowed(virDomainNetDefPtr iface ATTRIBUTE_UNUSED,
+ virNetDevBandwidthPtr newBandwidth ATTRIBUTE_UNUSED)
+{
+ return true;
+}
+
# endif
typedef char *(*networkDnsmasqLeaseFileNameFunc)(const char *netname);
--
2.4.6
--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list