[libvirt] [PATCH] Add support for 'passthru' mode for direct network interfaces
D. Herrendoerfer
d.herrendoerfer at herrendoerfer.name
Wed May 18 11:32:46 UTC 2011
On May 18, 2011, at 10:53 AM, Daniel Veillard wrote:
> On Tue, May 17, 2011 at 08:19:17PM -0600, Eric Blake wrote:
>> On 05/17/2011 05:26 AM, D. Herrendoerfer wrote:
>>> This patch includes the documentation part.
>>>
>>> The error returned by libvirt when a using an older kernel
>>> is imho sufficient to point to the macvtap setup. Apart from that
>>> I doubt that someone will use this feature by chance. But still - I
>>> believe the error returned is detailed enough for now.
>>
>> Fair enough for me.
>>
>> Your patch came through rather mangled by your mailer; sometimes,
>> it is
>> worth sending a patch to yourself as a trial run to see if others
>> would
>> have a hard time running 'git am' on the resulting email, then figure
>> out how to tune 'git send-email' to do what you wanted for sending
>> the
>> patch. The git mailing list or IRC channel is a good resource for
>> figuring out configuration emails that make patch submission easier.
>>
>>>
>>> Signed-off-by: Dirk Herrendoerfer <d.herrendoerfer at
>>> herrendoerfer.name>
>>>
>>> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
>>> index 989dcf6..3f6bec8 100644
>>> --- a/docs/formatdomain.html.in
>>> +++ b/docs/formatdomain.html.in
>>> @@ -1429,6 +1429,12 @@
>>> external router or gateway and that device sends them back to
>>> the
>>> host. This procedure is followed if either the source or
>>> destination
>>> device is in <code>private</code> mode.</dd>
>>> + <dt><code>passthru</code></dt>
>>> + <dd>This feature allows to attach a virtual function of a
>>> SRIOV
>>> capable
>>
>> s/allows to attach/attaches/
>>
>>> + NIC directly to a VM without loosing the migration
>>> capability.
>>
>> s/loosing/losing/
>>
>>> + All packets are sent to the VF/IF of the configured network
>>> device.
>>> + Depending on the capabilities of the device additional
>>> prerequisites or
>>> + limitations may apply. <span class="since">(Since Linux
>>> 2.6.38.)</span></dd>
>>
>> Here's where part of the patch botching showed up. Also, when
>> possible,
>> we like to keep lines within 80 columns.
>>
>> The <span class="since"> annotations are for when a feature was
>> added to
>> libvirt (0.9.2 in this case), not when it was added elsewhere.
>>
>>> </dl>
>>>
>>> <pre>
>>> diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
>>> index 7163c6e..e2a66ae 100644
>>> --- a/docs/schemas/domain.rng
>>> +++ b/docs/schemas/domain.rng
>>> @@ -2351,7 +2351,7 @@
>>> </define>
>>> <define name="bridgeMode">
>>> <data type="string">
>>> - <param name="pattern">(vepa|bridge|private)</param>
>>> + <param name="pattern">(vepa|bridge|private|passthru)</param>
>>
>> We already have other cases of "passthrough" in our XML schema;
>> let's be
>> consistent and avoid abbreviations in the public interface.
>>
>>> </data>
>>> </define>
>>> <define name="addrMAC">
>>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>>> index d3efec6..4c4bfad 100644
>>> --- a/src/conf/domain_conf.c
>>> +++ b/src/conf/domain_conf.c
>>> @@ -383,7 +383,8 @@ VIR_ENUM_IMPL(virDomainSeclabel,
>>> VIR_DOMAIN_SECLABEL_LAST,
>>> VIR_ENUM_IMPL(virDomainNetdevMacvtap,
>>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_LAST,
>>> "vepa",
>>> "private",
>>> - "bridge")
>>> + "bridge",
>>> + "passthru" )
>>
>> Odd spacing, and same spelling issue.
>>
>>>
>>> VIR_ENUM_IMPL(virVirtualPort, VIR_VIRTUALPORT_TYPE_LAST,
>>> "none",
>>> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
>>> index a0f820c..70943f9 100644
>>> --- a/src/conf/domain_conf.h
>>> +++ b/src/conf/domain_conf.h
>>> @@ -335,6 +335,7 @@ enum virDomainNetdevMacvtapType {
>>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_VEPA,
>>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_PRIVATE,
>>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_BRIDGE,
>>> + VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU,
>>
>> But here, the abbreviation is fine (it's internal to the code).
>>
>>>
>>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_LAST,
>>> };
>>> diff --git a/src/util/macvtap.c b/src/util/macvtap.c
>>> index a7af0cb..1b274cc 100644
>>> --- a/src/util/macvtap.c
>>> +++ b/src/util/macvtap.c
>>> @@ -473,6 +473,9 @@ macvtapModeFromInt(enum
>>> virDomainNetdevMacvtapType
>>> mode)
>>> case VIR_DOMAIN_NETDEV_MACVTAP_MODE_BRIDGE:
>>> return MACVLAN_MODE_BRIDGE;
>>>
>>> + case VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU:
>>> + return MACVLAN_MODE_PASSTHRU;
>>
>> This fails to compile for me on kernel-2.6.35.13-91.fc14.x86_64,
>> but I
>> see on rawhide that this is 8, so we need a #define fallback value.
>> Shoot, in rawhide, it's an enum rather than a #define, so we need a
>> configure check rather than a simpler preprocessor check.
>>
>> This is what I'll probably push.
>>
>>
>> From f977a09221757826ee91dd966e8d726b0bc22501 Mon Sep 17 00:00:00
>> 2001
>> From: Dirk Herrendorefer <d.herrendoerfer at herrendoerfer.name>
>> Date: Tue, 17 May 2011 13:26:09 +0200
>> Subject: [PATCH] Add support for 'passthru' mode for direct network
>> interfaces
>>
>> starting with kernel 2.6.38 macvtap supports a 'passthru' mode for
>> attaching virtual functions of a SRIOV capable network card
>> directly to
>> a VM.
>> This patch adds the capability to configure such a device.
>>
>> Signed-off-by: Dirk Herrendoerfer
>> <d.herrendoerfer at herrendoerfer.name>
>> ---
>> AUTHORS | 1 +
>> configure.ac | 7 +++++++
>> docs/formatdomain.html.in | 7 +++++++
>> docs/schemas/domain.rng | 2 +-
>> src/conf/domain_conf.c | 3 ++-
>> src/conf/domain_conf.h | 1 +
>> src/util/macvtap.c | 12 ++++++++++--
>> src/util/macvtap.h | 1 +
>> 8 files changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/AUTHORS b/AUTHORS
>> index 1bb1f0f..a1e93db 100644
>> --- a/AUTHORS
>> +++ b/AUTHORS
>> @@ -170,6 +170,7 @@ Patches have also been contributed by:
>> index 233e4af..8db3226 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -2240,6 +2240,13 @@ if test "$with_macvtap" != "no" ; then
>> fi
>> AM_CONDITIONAL([WITH_MACVTAP], [test "$with_macvtap" = "yes"])
>> AC_MSG_RESULT([$with_macvtap])
>> +if test "$with_macvtap" = yes; then
>> + AC_CHECK_DECLS([MACVLAN_MODE_PASSTHRU], [], [], [[
>> + #include <sys/socket.h>
>> + #include <linux/if_link.h>
>> + ]])
>> +fi
>> +
>>
>> AC_ARG_WITH([virtualport],
>> AC_HELP_STRING([--with-virtualport],[enable virtual port support
>> @<:@default=check@:>@]),
>> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
>> index 989dcf6..70a120b 100644
>> --- a/docs/formatdomain.html.in
>> +++ b/docs/formatdomain.html.in
>> @@ -1429,6 +1429,13 @@
>> external router or gateway and that device sends them back to
>> the
>> host. This procedure is followed if either the source or
>> destination
>> device is in <code>private</code> mode.</dd>
>> + <dt><code>passthru</code></dt>
>> + <dd>This feature attaches a virtual function of a SRIOV
>> capable
>> + NIC directly to a VM without losing the migration capability.
>> + All packets are sent to the VF/IF of the configured network
>> device.
>> + Depending on the capabilities of the device additional
>> prerequisites or
>> + limitations may apply; for example, on Linux this requires
>> + kernel 2.6.38 or newer. <span class="since">Since 0.9.2</
>> span></dd>
>> </dl>
>>
>> <pre>
>> diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
>> index 7163c6e..b252547 100644
>> --- a/docs/schemas/domain.rng
>> +++ b/docs/schemas/domain.rng
>> @@ -2351,7 +2351,7 @@
>> </define>
>> <define name="bridgeMode">
>> <data type="string">
>> - <param name="pattern">(vepa|bridge|private)</param>
>> + <param name="pattern">(vepa|bridge|private|passthrough)</
>> param>
>> </data>
>> </define>
>> <define name="addrMAC">
>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>> index 498438a..3298c80 100644
>> --- a/src/conf/domain_conf.c
>> +++ b/src/conf/domain_conf.c
>> @@ -433,7 +433,8 @@ VIR_ENUM_IMPL(virDomainSeclabel,
>> VIR_DOMAIN_SECLABEL_LAST,
>> VIR_ENUM_IMPL(virDomainNetdevMacvtap,
>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_LAST,
>> "vepa",
>> "private",
>> - "bridge")
>> + "bridge",
>> + "passthrough")
>>
>> VIR_ENUM_IMPL(virVirtualPort, VIR_VIRTUALPORT_TYPE_LAST,
>> "none",
>> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
>> index fe42f21..5fe31d4 100644
>> --- a/src/conf/domain_conf.h
>> +++ b/src/conf/domain_conf.h
>> @@ -335,6 +335,7 @@ enum virDomainNetdevMacvtapType {
>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_VEPA,
>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_PRIVATE,
>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_BRIDGE,
>> + VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU,
>>
>> VIR_DOMAIN_NETDEV_MACVTAP_MODE_LAST,
>> };
>> diff --git a/src/util/macvtap.c b/src/util/macvtap.c
>> index a7af0cb..068638e 100644
>> --- a/src/util/macvtap.c
>> +++ b/src/util/macvtap.c
>> @@ -1,5 +1,5 @@
>> /*
>> - * Copyright (C) 2010 Red Hat, Inc.
>> + * Copyright (C) 2010-2011 Red Hat, Inc.
>> * Copyright (C) 2010 IBM Corporation
>> *
>> * This library is free software; you can redistribute it and/or
>> @@ -45,6 +45,11 @@
>>
>> # include <netlink/msg.h>
>>
>> +/* Older kernels lacked this enum value. */
>> +# if !HAVE_DECL_MACVLAN_MODE_PASSTHRU
>> +# define MACVLAN_MODE_PASSTHRU 8
>> +# endif
>> +
>> #endif /* WITH_MACVTAP || WITH_VIRTUALPORT */
>>
>> #include "util.h"
>> @@ -473,6 +478,9 @@ macvtapModeFromInt(enum
>> virDomainNetdevMacvtapType mode)
>> case VIR_DOMAIN_NETDEV_MACVTAP_MODE_BRIDGE:
>> return MACVLAN_MODE_BRIDGE;
>>
>> + case VIR_DOMAIN_NETDEV_MACVTAP_MODE_PASSTHRU:
>> + return MACVLAN_MODE_PASSTHRU;
>> +
>> case VIR_DOMAIN_NETDEV_MACVTAP_MODE_VEPA:
>> default:
>> return MACVLAN_MODE_VEPA;
>> @@ -546,7 +554,7 @@ configMacvtapTap(int tapfd, int vnet_hdr)
>> * be NULL if this function is supposed to choose a name
>> * @macaddress: The MAC address for the macvtap device
>> * @linkdev: The interface name of the NIC to connect to the external
>> bridge
>> - * @mode: int describing the mode for 'bridge', 'vepa' or 'private'.
>> + * @mode: int describing the mode for 'bridge', 'vepa', 'private' or
>> 'passthru'.
>> * @vnet_hdr: 1 to enable IFF_VNET_HDR, 0 to disable it
>> * @vmuuid: The UUID of the VM the macvtap belongs to
>> * @virtPortProfile: pointer to object holding the virtual port
>> profile
>> data
>> diff --git a/src/util/macvtap.h b/src/util/macvtap.h
>> index 54205c7..c45dd13 100644
>> --- a/src/util/macvtap.h
>> +++ b/src/util/macvtap.h
>> @@ -92,6 +92,7 @@ void delMacvtap(const char *ifname,
>> # define MACVTAP_MODE_PRIVATE_STR "private"
>> # define MACVTAP_MODE_VEPA_STR "vepa"
>> # define MACVTAP_MODE_BRIDGE_STR "bridge"
>> +# define MACVTAP_MODE_PASSTHRU_STR "passthru"
>>
>> int vpAssociatePortProfileId(const char *macvtap_ifname,
>> const unsigned char *macvtap_macaddr,
>
> That patch looks fine to me, ACK,
> The only unresolved uncertainty to me is what happen if you try to use
> it on a kernel without the support ?
>
This looks fine, except in formatdomain.html.in the feature is still
called
passthru.
Used on a system without passthru support this raises an error
indicating a
failed macvtap setup.
Dirk.
> Daniel
>
> --
> Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
> daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
> http://veillard.com/ | virtualization library http://libvirt.org/
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