From dddad4bcb452f684b9c0e9454f43ef0eba2280b5 Mon Sep 17 00:00:00 2001 From: Jiri Denemark Date: Fri, 4 Dec 2009 16:55:59 +0100 Subject: [PATCH] Support for interface model='netfront' Xen HVM guests with PV drivers end up with two network interfaces for each configured interface. One of them being emulated by qemu and the other one paravirtual. As this might not be desirable, the attached patch provides a way for users to specify that only paravirtual network interface should be presented to the guest. The configuration was inspired by qemu/kvm driver, for which users can specify model='virtio' to use paravirtual network interface. The patch adds support for model='netfront' which results in type=netfront instead of type=ioemu (or nothing for newer xen versions) in guests native configuration. Xen's qemu ignores interfaces with type != ioemu and only paravirtual network device will be seen in the guest. Four possible configuration scenarios follow: - no model specified in domain's XML - libvirt will behave like before this change; it will set type=ioemu for HVM guests on xen host which is not newer than XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU - covered by existing tests - PV guest, any model - no functional change, model is passed as is (and ignored by the hypervisor) - covered by existing tests (e.g., *-net-e1000.*) - HVM guest, model=netfront - type is set to "netfront", model is not specified - covered by new *-net-netfront.* tests - HVM guest, model != netfront - type is set to "ioemu", model is passed as is - covered by new *-net-ioemu.* tests The fourth scenario feels like a regression for xen newer than XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU as users who had a model specified in their guest's configuration won't see a paravirtual interface in their guests any more. On the other hand, the reason for specifying a model is most likely the fact that they want to use such model which implies emulated interface. Users of older xen won't be affected at all as their xen provides paravirtual interface regardless of the type used. - src/xen/xend_internal.c: add netfront support for the xend backend - src/xen/xm_internal.c: add netfront support for the XM serialization too --- src/xen/xend_internal.c | 32 ++++++++++++++++++++++++-------- src/xen/xm_internal.c | 38 +++++++++++++++++++++++++++++++++----- 2 files changed, 57 insertions(+), 13 deletions(-) diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c index 66d2e7f17d..8822f44c81 100644 --- a/src/xen/xend_internal.c +++ b/src/xen/xend_internal.c @@ -1770,11 +1770,12 @@ xenDaemonParseSxprNets(virConnectPtr conn, for (cur = root; cur->kind == SEXPR_CONS; cur = cur->u.s.cdr) { node = cur->u.s.car; if (sexpr_lookup(node, "device/vif")) { - const char *tmp2, *model; + const char *tmp2, *model, *type; char buf[50]; tmp2 = sexpr_node(node, "device/vif/script"); tmp = sexpr_node(node, "device/vif/bridge"); model = sexpr_node(node, "device/vif/model"); + type = sexpr_node(node, "device/vif/type"); if (VIR_ALLOC(net) < 0) goto no_memory; @@ -1841,6 +1842,11 @@ xenDaemonParseSxprNets(virConnectPtr conn, !(net->model = strdup(model))) goto no_memory; + if (!model && type && + STREQ(type, "netfront") && + !(net->model = strdup("netfront"))) + goto no_memory; + if (VIR_REALLOC_N(def->nets, def->nnets + 1) < 0) goto no_memory; @@ -5500,15 +5506,25 @@ xenDaemonFormatSxprNet(virConnectPtr conn, !STRPREFIX(def->ifname, "vif")) virBufferVSprintf(buf, "(vifname '%s')", def->ifname); - if (def->model != NULL) + if (!hvm) { + if (def->model != NULL) + virBufferVSprintf(buf, "(model '%s')", def->model); + } + else if (def->model == NULL) { + /* + * apparently (type ioemu) breaks paravirt drivers on HVM so skip + * this from XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU + */ + if (xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) + virBufferAddLit(buf, "(type ioemu)"); + } + else if (STREQ(def->model, "netfront")) { + virBufferAddLit(buf, "(type netfront)"); + } + else { virBufferVSprintf(buf, "(model '%s')", def->model); - - /* - * apparently (type ioemu) breaks paravirt drivers on HVM so skip this - * from Xen 3.1.0 - */ - if (hvm && xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) virBufferAddLit(buf, "(type ioemu)"); + } if (!isAttach) virBufferAddLit(buf, ")"); diff --git a/src/xen/xm_internal.c b/src/xen/xm_internal.c index 40c199682e..6c60839e51 100644 --- a/src/xen/xm_internal.c +++ b/src/xen/xm_internal.c @@ -1020,6 +1020,7 @@ xenXMDomainConfigParse(virConnectPtr conn, virConfPtr conf) { while (list) { char script[PATH_MAX]; char model[10]; + char type[10]; char ip[16]; char mac[18]; char bridge[50]; @@ -1031,6 +1032,7 @@ xenXMDomainConfigParse(virConnectPtr conn, virConfPtr conf) { script[0] = '\0'; ip[0] = '\0'; model[0] = '\0'; + type[0] = '\0'; vifname[0] = '\0'; if ((list->type != VIR_CONF_STRING) || (list->str == NULL)) @@ -1076,6 +1078,13 @@ xenXMDomainConfigParse(virConnectPtr conn, virConfPtr conf) { _("Model %s too big for destination"), data); goto skipnic; } + } else if (STRPREFIX(key, "type=")) { + int len = nextkey ? (nextkey - data) : sizeof(type) - 1; + if (virStrncpy(type, data, len, sizeof(type)) == NULL) { + xenXMError(conn, VIR_ERR_INTERNAL_ERROR, + _("Type %s too big for destination"), data); + goto skipnic; + } } else if (STRPREFIX(key, "vifname=")) { int len = nextkey ? (nextkey - data) : sizeof(vifname) - 1; if (virStrncpy(vifname, data, len, sizeof(vifname)) == NULL) { @@ -1145,10 +1154,16 @@ xenXMDomainConfigParse(virConnectPtr conn, virConfPtr conf) { !(net->data.ethernet.ipaddr = strdup(ip))) goto no_memory; } + if (model[0] && !(net->model = strdup(model))) goto no_memory; + if (!model[0] && type[0] && + STREQ(type, "netfront") && + !(net->model = strdup("netfront"))) + goto no_memory; + if (vifname[0] && !(net->ifname = strdup(vifname))) goto no_memory; @@ -2092,12 +2107,25 @@ static int xenXMDomainConfigFormatNet(virConnectPtr conn, goto cleanup; } - if (hvm && priv->xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) + if (!hvm) { + if (net->model != NULL) + virBufferVSprintf(&buf, ",model=%s", net->model); + } + else if (net->model == NULL) { + /* + * apparently type ioemu breaks paravirt drivers on HVM so skip this + * from XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU + */ + if (priv->xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) + virBufferAddLit(&buf, ",type=ioemu"); + } + else if (STREQ(net->model, "netfront")) { + virBufferAddLit(&buf, ",type=netfront"); + } + else { + virBufferVSprintf(&buf, ",model=%s", net->model); virBufferAddLit(&buf, ",type=ioemu"); - - if (net->model) - virBufferVSprintf(&buf, ",model=%s", - net->model); + } if (net->ifname) virBufferVSprintf(&buf, ",vifname=%s",