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='xenpv' which results in type=xenpv 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. A possible addition to this would be to force type=ioemu for all other models which would result in only emulated network device to be provided for an HVM guest on xen newer then XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU. No type would be configured when model is missing in domains XML. If you think this is a good idea, I'll prepare a second version of the patch. Signed-off-by: Jiri Denemark <jdenemar@redhat.com> --- src/xen/xend_internal.c | 25 +++++++++++++++++-------- src/xen/xm_internal.c | 19 ++++++++++++++----- 2 files changed, 31 insertions(+), 13 deletions(-) diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c index e370eb8..9ea59c7 100644 --- a/src/xen/xend_internal.c +++ b/src/xen/xend_internal.c @@ -5427,6 +5427,7 @@ xenDaemonFormatSxprNet(virConnectPtr conn, int isAttach) { const char *script = DEFAULT_VIF_SCRIPT; + int pv_only = 0; if (def->type != VIR_DOMAIN_NET_TYPE_BRIDGE && def->type != VIR_DOMAIN_NET_TYPE_NETWORK && @@ -5495,15 +5496,23 @@ xenDaemonFormatSxprNet(virConnectPtr conn, !STRPREFIX(def->ifname, "vif")) virBufferVSprintf(buf, "(vifname '%s')", def->ifname); - if (def->model != NULL) - virBufferVSprintf(buf, "(model '%s')", def->model); + if (def->model != NULL) { + if (hvm && STREQ(def->model, "xenpv")) + pv_only = 1; + 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 (pv_only) + virBufferAddLit(buf, "(type xenpv)"); + else { + /* + * 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 40c1996..fe4bcbd 100644 --- a/src/xen/xm_internal.c +++ b/src/xen/xm_internal.c @@ -2041,6 +2041,7 @@ static int xenXMDomainConfigFormatNet(virConnectPtr conn, virConfValuePtr val, tmp; char *str; xenUnifiedPrivatePtr priv = (xenUnifiedPrivatePtr) conn->privateData; + int pv_only = 0; virBufferVSprintf(&buf, "mac=%02x:%02x:%02x:%02x:%02x:%02x", net->mac[0], net->mac[1], @@ -2092,12 +2093,20 @@ static int xenXMDomainConfigFormatNet(virConnectPtr conn, goto cleanup; } - if (hvm && priv->xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) - virBufferAddLit(&buf, ",type=ioemu"); + if (net->model) { + if (hvm && STREQ(net->model, "xenpv")) + pv_only = 1; + else + virBufferVSprintf(&buf, ",model=%s", + net->model); + } - if (net->model) - virBufferVSprintf(&buf, ",model=%s", - net->model); + if (pv_only) + virBufferAddLit(&buf, ",type=xenpv"); + else { + if (hvm && priv->xendConfigVersion <= XEND_CONFIG_MAX_VERS_NET_TYPE_IOEMU) + virBufferAddLit(&buf, ",type=ioemu"); + } if (net->ifname) virBufferVSprintf(&buf, ",vifname=%s", -- 1.6.5.3