[libvirt] [PATCH] Added capability to set and restore the MAC address of a NIC when using PASSTHROUGH mode with DIRECT type NICs. This is required to support SRIOV capable NICs with firmware implemented on-card switches.
Dirk Herrendoerfer
d.herrendoerfer at herrendoerfer.name
Fri Jun 10 11:40:04 UTC 2011
---
src/libvirt_macvtap.syms | 2 +
src/qemu/qemu_command.c | 48 +++++++++++++++
src/qemu/qemu_process.c | 45 ++++++++++++++
src/util/macvtap.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++
src/util/macvtap.h | 6 ++
5 files changed, 250 insertions(+), 0 deletions(-)
diff --git a/src/libvirt_macvtap.syms b/src/libvirt_macvtap.syms
index b48565b..0520cb5 100644
--- a/src/libvirt_macvtap.syms
+++ b/src/libvirt_macvtap.syms
@@ -6,5 +6,7 @@
# macvtap.h
delMacvtap;
openMacvtapTap;
+get_macaddr;
+set_macaddr;
vpAssociatePortProfileId;
vpDisassociatePortProfileId;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 4e68241..41972fa 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -118,6 +118,7 @@ qemuPhysIfaceConnect(virDomainDefPtr def,
int rc;
#if WITH_MACVTAP
char *res_ifname = NULL;
+ unsigned char old_macaddr[6];
int vnet_hdr = 0;
int err;
@@ -125,6 +126,53 @@ qemuPhysIfaceConnect(virDomainDefPtr def,
net->model && STREQ(net->model, "virtio"))
vnet_hdr = 1;
+ /** Note: When using PASSTHROUGH mode with MACVTAP devices the link
+ * devices's MAC address must be set to the VMs MAC address. In
+ * order to not confuse the first switch or bridge in line this MAC
+ * address must be reset when the VM is shut down.
+ * This is especially important when using SRIOV capable cards that
+ * emulate their switch in firmware.
+ */
+ if ( net->data.direct.mode == VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU ) {
+ rc = get_macaddr(&old_macaddr, 6, net->data.direct.linkdev);
+ if (rc) {
+ virReportSystemError(rc,
+ _("Getting MAC address from '%s' "
+ "to '%02x:%02x:%02x:%02x:%02x:%02x' failed."),
+ net->data.direct.linkdev,
+ old_macaddr[0],old_macaddr[1],old_macaddr[2],
+ old_macaddr[3],old_macaddr[4],old_macaddr[5]);
+ } else {
+ char oldmacname[256], newmacname[256];
+
+ sprintf(oldmacname,"%02x:%02x:%02x:%02x:%02x:%02x",
+ old_macaddr[0],old_macaddr[1],old_macaddr[2],
+ old_macaddr[3],old_macaddr[4],old_macaddr[5]);
+
+ sprintf(newmacname,"/tmp/%s@%02x:%02x:%02x:%02x:%02x:%02x",
+ net->data.direct.linkdev,
+ net->mac[0],net->mac[1],net->mac[2],
+ net->mac[3],net->mac[4],net->mac[5]);
+
+ rc = symlink (oldmacname, newmacname);
+ if (rc) {
+ virReportSystemError(rc,
+ _("MAC link file creation failed for %s."),
+ net->data.direct.linkdev);
+ }
+ }
+
+ rc = set_macaddr(net->mac, 6, net->data.direct.linkdev);
+ if (rc) {
+ virReportSystemError(rc,
+ _("Setting MAC address on '%s' to "
+ "'%02x:%02x:%02x:%02x:%02x:%02x' failed."),
+ net->data.direct.linkdev,
+ net->mac[0],net->mac[1],net->mac[2],
+ net->mac[3],net->mac[4],net->mac[5]);
+ }
+ }
+
rc = openMacvtapTap(net->ifname, net->mac, net->data.direct.linkdev,
net->data.direct.mode, vnet_hdr, def->uuid,
&net->data.direct.virtPortProfile, &res_ifname,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 1efe024..127acb8 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -2663,6 +2663,51 @@ void qemuProcessStop(struct qemud_driver *driver,
if (net->type == VIR_DOMAIN_NET_TYPE_DIRECT) {
delMacvtap(net->ifname, net->mac, net->data.direct.linkdev,
&net->data.direct.virtPortProfile);
+
+ if ( net->data.direct.mode == VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU ) {
+ char newmacname[256], linkdata[64];
+ unsigned int old_macaddr[6];
+
+ sprintf(newmacname,"/tmp/%s@%02x:%02x:%02x:%02x:%02x:%02x",
+ net->data.direct.linkdev,
+ net->mac[0],net->mac[1],net->mac[2],
+ net->mac[3],net->mac[4],net->mac[5]);
+
+ ret = readlink (newmacname, linkdata, 64);
+ if ( ret == 17 ) {
+ linkdata[17] = 0;
+
+ ret = sscanf(linkdata,"%x:%x:%x:%x:%x:%x",
+ &old_macaddr[0],&old_macaddr[1],&old_macaddr[2],
+ &old_macaddr[3],&old_macaddr[4],&old_macaddr[5]);
+ if ( ret == 6 ) {
+ unsigned char oldmac[6];
+ oldmac[0] = (unsigned char)(old_macaddr[0] & 0xFF) ;
+ oldmac[1] = (unsigned char)(old_macaddr[1] & 0xFF) ;
+ oldmac[2] = (unsigned char)(old_macaddr[2] & 0xFF) ;
+ oldmac[3] = (unsigned char)(old_macaddr[3] & 0xFF) ;
+ oldmac[4] = (unsigned char)(old_macaddr[4] & 0xFF) ;
+ oldmac[5] = (unsigned char)(old_macaddr[5] & 0xFF) ;
+
+ VIR_WARN(("Resetting MAC address on '%s' "
+ "to '%02x:%02x:%02x:%02x:%02x:%02x'."),
+ net->data.direct.linkdev,
+ oldmac[0],oldmac[1],oldmac[2],
+ oldmac[3],oldmac[4],oldmac[5]);
+ /*reset mac and remove link file-ignore restults*/
+ ret = set_macaddr(oldmac, 6, net->data.direct.linkdev);
+ ret = unlink(newmacname);
+ } else {
+ VIR_WARN(("Scanning MAC address from '%s' "
+ "failed ! Got %i values."),
+ linkdata, ret);
+ }
+ } else {
+ VIR_WARN(("Reading MAC address from '%s' failed ! "
+ "Got %i bytes."),
+ newmacname, ret);
+ }
+ }
VIR_FREE(net->ifname);
}
}
diff --git a/src/util/macvtap.c b/src/util/macvtap.c
index 068638e..1026a84 100644
--- a/src/util/macvtap.c
+++ b/src/util/macvtap.c
@@ -191,6 +191,155 @@ err_exit:
# if WITH_MACVTAP
+/**
+ * get_macaddr:
+ * Get the MAC address of a network device
+ *
+ * @macaddress: Pointer where the MAC address will be stored
+ * @macaddrsize: Size of the MAC address.
+ * @srcdev: The interface name of the NIC to get the MAC from
+ *
+ * Returns zero in case of success,
+ * negative value otherwise with error reported.
+ *
+ */
+int
+get_macaddr(const unsigned char *macaddress, int macaddrsize,
+ const char *srcdev )
+{
+ int sockfd;
+ int io;
+ char buffer[1024];
+ struct ifreq ifr;
+
+ strcpy(ifr.ifr_name, srcdev);
+
+ sockfd = socket(AF_INET, SOCK_STREAM, 0);
+ if(sockfd < 0){
+ return -1;
+ }
+
+ io = ioctl(sockfd, SIOCGIFHWADDR, (char *)&ifr);
+ if(io < 0){
+ return -1;
+ }
+
+ bcopy( ifr.ifr_ifru.ifru_hwaddr.sa_data, macaddress, macaddrsize);
+
+ return 0;
+}
+
+/**
+ * Set_macaddr:
+ * Set the MAC address of a network device
+ *
+ * @macaddress: MAC address to assign to the NIC
+ * @macaddrsize: Size of the MAC address.
+ * @srcdev: The interface name of the NIC
+ *
+ * Returns zero in case of success,
+ * negative value otherwise with error reported.
+ *
+ */
+int
+set_macaddr(const unsigned char *macaddress, int macaddrsize,
+ const char *srcdev )
+{
+ int rc = 0;
+ struct nlmsghdr *resp;
+ struct nlmsgerr *err;
+ struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
+ int ifindex;
+ unsigned char *recvbuf = NULL;
+ unsigned int recvbuflen;
+ struct nl_msg *nl_msg;
+ struct nlattr *linkinfo;
+
+ if (ifaceGetIndex(true, srcdev, &ifindex) != 0)
+ return -1;
+
+ nl_msg = nlmsg_alloc_simple(RTM_SETLINK, NLM_F_REQUEST);
+
+ if (!nl_msg) {
+ virReportOOMError();
+ return -1;
+ }
+
+ if (nlmsg_append(nl_msg, &ifinfo, sizeof(ifinfo), NLMSG_ALIGNTO) < 0)
+ goto buffer_too_small;
+
+ if (nla_put_u32(nl_msg, IFLA_LINK, ifindex) < 0)
+ goto buffer_too_small;
+
+ if (nla_put(nl_msg, IFLA_ADDRESS, macaddrsize, macaddress) < 0)
+ goto buffer_too_small;
+
+ if (srcdev &&
+ nla_put(nl_msg, IFLA_IFNAME, strlen(srcdev)+1, srcdev) < 0)
+ goto buffer_too_small;
+
+ if (nlComm(nl_msg, &recvbuf, &recvbuflen, 0) < 0) {
+ rc = -1;
+ goto err_exit;
+ }
+
+ if (recvbuflen < NLMSG_LENGTH(0) || recvbuf == NULL)
+ goto malformed_resp;
+
+ resp = (struct nlmsghdr *)recvbuf;
+
+ switch (resp->nlmsg_type) {
+ case NLMSG_ERROR:
+ err = (struct nlmsgerr *)NLMSG_DATA(resp);
+ if (resp->nlmsg_len < NLMSG_LENGTH(sizeof(*err)))
+ goto malformed_resp;
+
+ switch (err->error) {
+
+ case 0:
+ break;
+
+ case -EEXIST:
+ rc = -1;
+ break;
+
+ default:
+ macvtapError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("error setting device mac address"));
+ rc = -1;
+ }
+ break;
+
+ case NLMSG_DONE:
+ break;
+
+ default:
+ goto malformed_resp;
+ }
+
+err_exit:
+ nlmsg_free(nl_msg);
+
+ VIR_FREE(recvbuf);
+
+ return rc;
+
+malformed_resp:
+ nlmsg_free(nl_msg);
+
+ macvtapError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("malformed netlink response message"));
+ VIR_FREE(recvbuf);
+ return -1;
+
+buffer_too_small:
+ nlmsg_free(nl_msg);
+
+ macvtapError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("allocated netlink buffer is too small"));
+ return -1;
+}
+
static int
link_add(const char *type,
const unsigned char *macaddress, int macaddrsize,
diff --git a/src/util/macvtap.h b/src/util/macvtap.h
index a1383c4..d71546a 100644
--- a/src/util/macvtap.h
+++ b/src/util/macvtap.h
@@ -75,6 +75,12 @@ enum virVMOperationType {
# include "internal.h"
+int get_macaddr(const unsigned char *macaddress, int macaddrsize,
+ const char *srcdev );
+
+int set_macaddr(const unsigned char *macaddress, int macaddrsize,
+ const char *srcdev );
+
int openMacvtapTap(const char *ifname,
const unsigned char *macaddress,
const char *linkdev,
--
1.7.5.2
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