[libvirt] [PATCH v2 06/12] util: Learn virNetDevTapCreate multiqueue network
Michal Privoznik
mprivozn at redhat.com
Mon May 13 17:23:03 UTC 2013
Currently, the function knows how to open a TAP device for a single
time. However, in case of multiqueue network we need to open it multiple
times. Moreover, when doing TUNSETIFF ioctl, the IFF_MULTI_QUEUE flag
shall be requested. This commit changes a behaviour slightly as well.
Till now it was possible to pass NULL as an @fd address by which caller
didn't care about returned FD. While this was used only in UML driver,
the appropriate UML code snippets has been changed as well.
---
src/network/bridge_driver.c | 2 +-
src/qemu/qemu_command.c | 2 +-
src/uml/uml_conf.c | 5 +-
src/util/virnetdevtap.c | 115 ++++++++++++++++++++++++--------------------
src/util/virnetdevtap.h | 2 +
5 files changed, 72 insertions(+), 54 deletions(-)
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 99c1316..f81e925 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -2444,7 +2444,7 @@ networkStartNetworkVirtual(struct network_driver *driver,
/* Keep tun fd open and interface up to allow for IPv6 DAD to happen */
if (virNetDevTapCreateInBridgePort(network->def->bridge,
&macTapIfName, &network->def->mac,
- NULL, &tapfd, NULL, NULL,
+ NULL, &tapfd, 1, NULL, NULL,
VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE |
VIR_NETDEV_TAP_CREATE_IFUP |
VIR_NETDEV_TAP_CREATE_PERSIST) < 0) {
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index ec061d1..e4bb2b7 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -355,7 +355,7 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
if (cfg->privileged)
err = virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac,
- def->uuid, &tapfd,
+ def->uuid, &tapfd, 1,
virDomainNetGetActualVirtPortProfile(net),
virDomainNetGetActualVlan(net),
tap_create_flags);
diff --git a/src/uml/uml_conf.c b/src/uml/uml_conf.c
index 52b705c..3fda7e4 100644
--- a/src/uml/uml_conf.c
+++ b/src/uml/uml_conf.c
@@ -109,6 +109,7 @@ umlConnectTapDevice(virConnectPtr conn,
const char *bridge)
{
bool template_ifname = false;
+ int tapfd;
if (!net->ifname ||
STRPREFIX(net->ifname, VIR_NET_GENERATED_PREFIX) ||
@@ -121,7 +122,7 @@ umlConnectTapDevice(virConnectPtr conn,
}
if (virNetDevTapCreateInBridgePort(bridge, &net->ifname, &net->mac,
- vm->uuid, NULL,
+ vm->uuid, &tapfd, 1,
virDomainNetGetActualVirtPortProfile(net),
virDomainNetGetActualVlan(net),
VIR_NETDEV_TAP_CREATE_IFUP |
@@ -139,9 +140,11 @@ umlConnectTapDevice(virConnectPtr conn,
}
}
+ VIR_FORCE_CLOSE(tapfd);
return 0;
error:
+ VIR_FORCE_CLOSE(tapfd);
return -1;
}
diff --git a/src/util/virnetdevtap.c b/src/util/virnetdevtap.c
index 75599db..ee839e3 100644
--- a/src/util/virnetdevtap.c
+++ b/src/util/virnetdevtap.c
@@ -140,7 +140,8 @@ virNetDevProbeVnetHdr(int tapfd)
/**
* virNetDevTapCreate:
* @ifname: the interface name
- * @tapfd: file descriptor return value for the new tap device
+ * @tapfds: file descriptor return value for the new tap device
+ * @tapfdSize: size of @tapfd
* @flags: OR of virNetDevTapCreateFlags. Only one flag is recognized:
*
* VIR_NETDEV_TAP_CREATE_VNET_HDR
@@ -148,76 +149,85 @@ virNetDevProbeVnetHdr(int tapfd)
* VIR_NETDEV_TAP_CREATE_PERSIST
* - The device will persist after the file descriptor is closed
*
- * Creates a tap interface.
- * If the @tapfd parameter is supplied, the open tap device file descriptor
- * will be returned, otherwise the TAP device will be closed. The caller must
- * use virNetDevTapDelete to remove a persistent TAP device when it is no
- * longer needed.
+ * Creates a tap interface. The caller must use virNetDevTapDelete to
+ * remove a persistent TAP device when it is no longer needed. In case
+ * @tapfdSize is greater than one, multiqueue extension is requested
+ * from kernel.
*
* Returns 0 in case of success or -1 on failure.
*/
int virNetDevTapCreate(char **ifname,
int *tapfd,
+ int tapfdSize,
unsigned int flags)
{
- int fd;
+ int i;
struct ifreq ifr;
int ret = -1;
- if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
- virReportSystemError(errno, "%s",
- _("Unable to open /dev/net/tun, is tun module loaded?"));
- return -1;
- }
-
memset(&ifr, 0, sizeof(ifr));
+ for (i = 0; i < tapfdSize; i++) {
+ int fd;
- ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
+ if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Unable to open /dev/net/tun, is tun module loaded?"));
+ goto cleanup;
+ }
+
+ memset(&ifr, 0, sizeof(ifr));
+
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+ /* If tapfdSize is greater than one, request multiqueue */
+ if (tapfdSize > 1)
+ ifr.ifr_flags |= IFF_MULTI_QUEUE;
# ifdef IFF_VNET_HDR
- if ((flags & VIR_NETDEV_TAP_CREATE_VNET_HDR) &&
- virNetDevProbeVnetHdr(fd))
- ifr.ifr_flags |= IFF_VNET_HDR;
+ if ((flags & VIR_NETDEV_TAP_CREATE_VNET_HDR) &&
+ virNetDevProbeVnetHdr(fd))
+ ifr.ifr_flags |= IFF_VNET_HDR;
# endif
- if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) {
- virReportSystemError(ERANGE,
- _("Network interface name '%s' is too long"),
- *ifname);
- goto cleanup;
+ if (virStrcpyStatic(ifr.ifr_name, *ifname) == NULL) {
+ virReportSystemError(ERANGE,
+ _("Network interface name '%s' is too long"),
+ *ifname);
+ goto cleanup;
- }
+ }
- if (ioctl(fd, TUNSETIFF, &ifr) < 0) {
- virReportSystemError(errno,
- _("Unable to create tap device %s"),
- NULLSTR(*ifname));
- goto cleanup;
- }
+ if (ioctl(fd, TUNSETIFF, &ifr) < 0) {
+ virReportSystemError(errno,
+ _("Unable to create tap device %s"),
+ NULLSTR(*ifname));
+ goto cleanup;
+ }
- if ((flags & VIR_NETDEV_TAP_CREATE_PERSIST) &&
- (errno = ioctl(fd, TUNSETPERSIST, 1))) {
- virReportSystemError(errno,
- _("Unable to set tap device %s to persistent"),
- NULLSTR(*ifname));
- goto cleanup;
- }
+ if (i == 0) {
+ /* In case we are looping more than once, set other
+ * TAPs to have the same name */
+ VIR_FREE(*ifname);
+ if (ifr.ifr_name && VIR_STRDUP(*ifname, ifr.ifr_name) < 0)
+ goto cleanup;
+ }
- VIR_FREE(*ifname);
- if (!(*ifname = strdup(ifr.ifr_name))) {
- virReportOOMError();
- goto cleanup;
+ if ((flags & VIR_NETDEV_TAP_CREATE_PERSIST) &&
+ (errno = ioctl(fd, TUNSETPERSIST, 1))) {
+ virReportSystemError(errno,
+ _("Unable to set tap device %s to persistent"),
+ NULLSTR(*ifname));
+ goto cleanup;
+ }
+ tapfd[i] = fd;
}
- if (tapfd)
- *tapfd = fd;
- else
- VIR_FORCE_CLOSE(fd);
ret = 0;
cleanup:
- if (ret < 0)
- VIR_FORCE_CLOSE(fd);
+ if (ret < 0) {
+ for (i = 0; i < tapfdSize; i++)
+ VIR_FORCE_CLOSE(tapfd[i]);
+ }
return ret;
}
@@ -266,6 +276,7 @@ cleanup:
#else /* ! TUNSETIFF */
int virNetDevTapCreate(char **ifname ATTRIBUTE_UNUSED,
int *tapfd ATTRIBUTE_UNUSED,
+ int tapfdSize ATTRIBUTE_UNUSED,
unsigned int flags ATTRIBUTE_UNUSED)
{
virReportSystemError(ENOSYS, "%s",
@@ -286,7 +297,8 @@ int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED)
* @brname: the bridge name
* @ifname: the interface name (or name template)
* @macaddr: desired MAC address
- * @tapfd: file descriptor return value for the new tap device
+ * @tapfd: array of file descriptor return value for the new tap device
+ * @tapfdSize: size of @tapfd
* @virtPortProfile: bridge/port specific configuration
* @flags: OR of virNetDevTapCreateFlags:
@@ -314,6 +326,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
const virMacAddrPtr macaddr,
const unsigned char *vmuuid,
int *tapfd,
+ int tapfdSize,
virNetDevVPortProfilePtr virtPortProfile,
virNetDevVlanPtr virtVlan,
unsigned int flags)
@@ -321,7 +334,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
virMacAddr tapmac;
char macaddrstr[VIR_MAC_STRING_BUFLEN];
- if (virNetDevTapCreate(ifname, tapfd, flags) < 0)
+ if (virNetDevTapCreate(ifname, tapfd, tapfdSize, flags) < 0)
return -1;
/* We need to set the interface MAC before adding it
@@ -372,9 +385,9 @@ int virNetDevTapCreateInBridgePort(const char *brname,
return 0;
- error:
- if (tapfd)
- VIR_FORCE_CLOSE(*tapfd);
+error:
+ while (tapfdSize)
+ VIR_FORCE_CLOSE(tapfd[--tapfdSize]);
return -1;
}
diff --git a/src/util/virnetdevtap.h b/src/util/virnetdevtap.h
index 6bfc80c..cb6c284 100644
--- a/src/util/virnetdevtap.h
+++ b/src/util/virnetdevtap.h
@@ -29,6 +29,7 @@
int virNetDevTapCreate(char **ifname,
int *tapfd,
+ int tapfdSize,
unsigned int flags)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
@@ -55,6 +56,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
const virMacAddrPtr macaddr,
const unsigned char *vmuuid,
int *tapfd,
+ int tapfdSize,
virNetDevVPortProfilePtr virtPortProfile,
virNetDevVlanPtr virtVlan,
unsigned int flags)
--
1.8.2.1
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