6:53 a.m.
Dear Users/Developers,
I am using a KVM Ubuntu VM as a degrader to apply specific delays to
incoming packets. As the delay for my packets can be higher than 7.5
seconds, there is not enough buffer on my interface to buffer all the
packets. Therefore those overflowing packets are dropped in the machine and
not forwarded.
When I tried to use the command ethtool -G ens8 rx 512 to increase the
buffer size, I get the following error.
Cannot set device ring parameters: Operation not permitted
I have kept the VM xml files as specified in the link :
https://libvirt.org/formatdomain.html. The value that I kept in my xml file
is as follows.
<interface type='direct'>
<mac address='52:54:00:72:f9:eb'/>
<source dev='enp7s0f0' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'
mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off'
ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x08'
function='0x0'/>
</interface>
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='enp7s0f1' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'
mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off'
ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x09'
function='0x0'/>
After I saved the xml and redefined the machine and started it up, I
checked to see if the buffers are increased. I still see that the buffers
are as follows.
Ring parameters for ens9:
Pre-set maximums:
RX: 4096
RX Mini: 0
RX Jumbo: 0
TX: 4096
Current hardware settings:
RX: *256*
RX Mini: 0
RX Jumbo: 0
TX: *256*
How can I increase the buffer on my KVM VM?
Best Regards,
Ashish Kurian
7:50 a.m.
On 10/25/2017 01:53 PM, Ashish Kurian wrote:
Dear Users/Developers,
I am using a KVM Ubuntu VM as a degrader to apply specific delays to
incoming packets. As the delay for my packets can be higher than 7.5
seconds, there is not enough buffer on my interface to buffer all the
packets. Therefore those overflowing packets are dropped in the machine and
not forwarded.
When I tried to use the command ethtool -G ens8 rx 512 to increase the
buffer size, I get the following error.
Cannot set device ring parameters: Operation not permitted
I have kept the VM xml files as specified in the link :
https://libvirt.org/formatdomain.html. The value that I kept in my xml file
is as follows.
<interface type='direct'>
<mac address='52:54:00:72:f9:eb'/>
<source dev='enp7s0f0' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'
mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x08'
function='0x0'/>
</interface>
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='enp7s0f1' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off' tso6='off'
ecn='off' ufo='off'
mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x09'
function='0x0'/>
So what does the qemu command line look like? You can find it in either
libvirtd log or domain log.
http://wiki.libvirt.org/page/DebugLogs
Michal
10:07 a.m.
Hi Michal,
What I found was that when I restarted the machine and did a virsh edit
command to see the xml config, I see that it is was not actually changed.
This suggests why I saw 256 again after restarting.
So now I tried again to edit the xml via virsh edit command and used the
following to set the parameters.
<driver name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off'
queues='1' rx_queue_size='512' tx_queue_size='512'>
</driver>
It was not accepted and I got the error saying :
error: XML document failed to validate against schema: Unable to validate
doc against /usr/share/libvirt/schemas/domain.rng
Extra element devices in interleave
Element domain failed to validate content
What does this imply? I have two more other interfaces and do I have to the
same to them also?
Btw, there are now logs generated now in the domain log or libvirtd log
Best Regards,
Ashish Kurian
On Wed, Oct 25, 2017 at 2:50 PM, Michal Privoznik <mprivozn(a)redhat.com>
wrote:
On 10/25/2017 01:53 PM, Ashish Kurian wrote:
> Dear Users/Developers,
>
> I am using a KVM Ubuntu VM as a degrader to apply specific delays to
> incoming packets. As the delay for my packets can be higher than 7.5
> seconds, there is not enough buffer on my interface to buffer all the
> packets. Therefore those overflowing packets are dropped in the machine
and
> not forwarded.
>
> When I tried to use the command ethtool -G ens8 rx 512 to increase the
> buffer size, I get the following error.
>
> Cannot set device ring parameters: Operation not permitted
>
> I have kept the VM xml files as specified in the link :
> https://libvirt.org/formatdomain.html. The value that I kept in my xml
file
> is as follows.
>
> <interface type='direct'>
> <mac address='52:54:00:72:f9:eb'/>
> <source dev='enp7s0f0' mode='vepa'/>
> <model type='virtio'/>
> <driver name='vhost' queues='5'
rx_queue_size='512'
> tx_queue_size='512'>
> <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off'
> mrg_rxbuf='off'/>
> <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> </driver>
> <address type='pci' domain='0x0000' bus='0x00'
slot='0x08'
> function='0x0'/>
> </interface>
> <interface type='direct'>
> <mac address='52:54:00:00:b5:99'/>
> <source dev='enp7s0f1' mode='vepa'/>
> <model type='virtio'/>
> <driver name='vhost' queues='5'
rx_queue_size='512'
> tx_queue_size='512'>
> <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off'
> mrg_rxbuf='off'/>
> <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> </driver>
> <address type='pci' domain='0x0000' bus='0x00'
slot='0x09'
> function='0x0'/>
So what does the qemu command line look like? You can find it in either
libvirtd log or domain log.
http://wiki.libvirt.org/page/DebugLogs
Michal
1:33 p.m.
Hi Michal,
An update to what I have already said : when I try adding <driver
name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off' queues='1'
rx_queue_size='512' tx_queue_size='512'> although it showed me the
error as
mentioned, when I checked the xml again I saw that <driver name='qemu'
txmode='iothread' ioeventfd='on' event_idx='off' > is added to
the
interface.
The missing parameters are : queues='1' rx_queue_size='512'
tx_queue_size='512'
Best Regards,
Ashish Kurian
On Wed, Oct 25, 2017 at 5:07 PM, Ashish Kurian <ashishbnv(a)gmail.com> wrote:
Hi Michal,
What I found was that when I restarted the machine and did a virsh edit
command to see the xml config, I see that it is was not actually changed.
This suggests why I saw 256 again after restarting.
So now I tried again to edit the xml via virsh edit command and used the
following to set the parameters.
<driver name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off'
queues='1' rx_queue_size='512' tx_queue_size='512'>
</driver>
It was not accepted and I got the error saying :
error: XML document failed to validate against schema: Unable to validate
doc against /usr/share/libvirt/schemas/domain.rng
Extra element devices in interleave
Element domain failed to validate content
What does this imply? I have two more other interfaces and do I have to
the same to them also?
Btw, there are now logs generated now in the domain log or libvirtd log
Best Regards,
Ashish Kurian
On Wed, Oct 25, 2017 at 2:50 PM, Michal Privoznik <mprivozn(a)redhat.com>
wrote:
> On 10/25/2017 01:53 PM, Ashish Kurian wrote:
> > Dear Users/Developers,
> >
> > I am using a KVM Ubuntu VM as a degrader to apply specific delays to
> > incoming packets. As the delay for my packets can be higher than 7.5
> > seconds, there is not enough buffer on my interface to buffer all the
> > packets. Therefore those overflowing packets are dropped in the machine
> and
> > not forwarded.
> >
> > When I tried to use the command ethtool -G ens8 rx 512 to increase the
> > buffer size, I get the following error.
> >
> > Cannot set device ring parameters: Operation not permitted
> >
> > I have kept the VM xml files as specified in the link :
> > https://libvirt.org/formatdomain.html. The value that I kept in my xml
> file
> > is as follows.
> >
> > <interface type='direct'>
> > <mac address='52:54:00:72:f9:eb'/>
> > <source dev='enp7s0f0' mode='vepa'/>
> > <model type='virtio'/>
> > <driver name='vhost' queues='5'
rx_queue_size='512'
> > tx_queue_size='512'>
> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
> ufo='off'
> > mrg_rxbuf='off'/>
> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> > </driver>
> > <address type='pci' domain='0x0000' bus='0x00'
slot='0x08'
> > function='0x0'/>
> > </interface>
> > <interface type='direct'>
> > <mac address='52:54:00:00:b5:99'/>
> > <source dev='enp7s0f1' mode='vepa'/>
> > <model type='virtio'/>
> > <driver name='vhost' queues='5'
rx_queue_size='512'
> > tx_queue_size='512'>
> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
> ufo='off'
> > mrg_rxbuf='off'/>
> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> > </driver>
> > <address type='pci' domain='0x0000' bus='0x00'
slot='0x09'
> > function='0x0'/>
>
> So what does the qemu command line look like? You can find it in either
> libvirtd log or domain log.
>
> http://wiki.libvirt.org/page/DebugLogs
>
> Michal
>
11:45 p.m.
Hi Ashish,
I have tested with your xml in the first mail, and it works for
rx_queue_size(see
below).
multiqueue need to work with vhost backend driver. And when you set
"queues=1" it will ignored.
Please check your qemu-kvm-rhev package, should be newer than
qemu-kvm-rhev-2.9.0-16.el7_4.2
And the logs?
tx_queue_size='512' will not work in the guest with direct type interface,
in fact, no matter what you set, it will not work and guest will get the
default '256'.
We only support vhost-user backend to have more than 256. refer to
https://libvirt.org/formatdomain.html#elementsNICSEthernet
tx_queue_size
The optional tx_queue_size attribute controls the size of virtio ring for
each queue as described above. The default value is hypervisor dependent
and may change across its releases. Moreover, some hypervisors may pose
some restrictions on actual value. For instance, QEMU v2.9 requires value
to be a power of two from [256, 1024] range. In addition to that, this may
work only for a subset of interface types, e.g. aforementioned QEMU enables
this option only for vhostuser type. Since 3.7.0 (QEMU and KVM only)
multiqueue only supports vhost as backend driver.
# rpm -q libvirt qemu-kvm-rhev
libvirt-3.2.0-14.el7_4.3.x86_64
qemu-kvm-rhev-2.9.0-16.el7_4.9.x86_64
1. the xml as below
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='eno1' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
2. after start the vm, check the qemu command line:
*-netdev
tap,fds=26:28:29:30:31,id=hostnet0,vhost=on,vhostfds=32:33:34:35:36*
-device
virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=off,host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,guest_tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
*mq=on,vectors=12,rx_queue_size=512,tx_queue_size=512*
,netdev=hostnet0,id=net0,mac=52:54:00:00:b5:99,bus=pci.0,addr=0x3
3. check on guest
# ethtool -g eth0
Ring parameters for eth0:
Pre-set maximums:
RX: *512 ==> rx_queue_size works*
RX Mini: 0
RX Jumbo: 0
TX: *256 ===> no change*
Current hardware settings:
RX: *512 **==> rx_queue_size works*
RX Mini: 0
RX Jumbo: 0
TX: *256 ===> no change*
# ethtool -l eth0
Channel parameters for eth0:
Pre-set maximums:
RX: 0
TX: 0
Other: 0
Combined: *5 ==> queues what we set*
Current hardware settings:
RX: 0
TX: 0
Other: 0
Combined: 1
If change to qemu as driver,
# virsh edit rhel7
..
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='eno1' mode='vepa'/>
<model type='virtio'/>
<driver name='qemu' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
..
Domain rhel7 XML configuration edited. ==> the xml can validate and save
# virsh start rhel7
Domain rhel7 started
# virsh dumpxml rhel7 | grep /interface -B9
<source dev='eno1' mode='vepa'/>
<target dev='macvtap0'/>
<model type='virtio'/>
*<driver name='qemu' queues='5' rx_queue_size='512'
tx_queue_size='512'>*
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
* -netdev tap,fds=26:28:29:30:31*,id=hostnet0 -device
virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=off,host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,guest_tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
*rx_queue_size=512,tx_queue_size=512*
,netdev=hostnet0,id=net0,mac=52:54:00:00:b5:99,bus=pci.0,addr=0x3
*"mq=on,vectors=12" is missing*, indicates there is no multiqueue
and check on guest
# ethtool -l eth0
Channel parameters for eth0:
Pre-set maximums:
RX: 0
TX: 0
Other: 0
Combined: 1 ==> no multiqueue
Current hardware settings:
RX: 0
TX: 0
Other: 0
Combined: 1
# ethtool -g eth0
Ring parameters for eth0:
Pre-set maximums:
RX: *512*
RX Mini: 0
RX Jumbo: 0
TX: 256
Current hardware settings:
RX: *512*
RX Mini: 0
RX Jumbo: 0
TX: 256
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
Internal phone: 8389413
On Thu, Oct 26, 2017 at 2:33 AM, Ashish Kurian <ashishbnv(a)gmail.com> wrote:
Hi Michal,
An update to what I have already said : when I try adding <driver
name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off' queues='1'
rx_queue_size='512' tx_queue_size='512'> although it showed me the
error as
mentioned, when I checked the xml again I saw that <driver name='qemu'
txmode='iothread' ioeventfd='on' event_idx='off' > is added to
the
interface.
The missing parameters are : queues='1' rx_queue_size='512'
tx_queue_size='512'
Best Regards,
Ashish Kurian
On Wed, Oct 25, 2017 at 5:07 PM, Ashish Kurian <ashishbnv(a)gmail.com>
wrote:
> Hi Michal,
>
> What I found was that when I restarted the machine and did a virsh edit
> command to see the xml config, I see that it is was not actually changed.
> This suggests why I saw 256 again after restarting.
>
> So now I tried again to edit the xml via virsh edit command and used the
> following to set the parameters.
>
> <driver name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off'
> queues='1' rx_queue_size='512' tx_queue_size='512'>
> </driver>
>
> It was not accepted and I got the error saying :
>
>
> error: XML document failed to validate against schema: Unable to validate
> doc against /usr/share/libvirt/schemas/domain.rng
> Extra element devices in interleave
> Element domain failed to validate content
>
> What does this imply? I have two more other interfaces and do I have to
> the same to them also?
>
> Btw, there are now logs generated now in the domain log or libvirtd log
>
>
>
>
>
> Best Regards,
> Ashish Kurian
>
> On Wed, Oct 25, 2017 at 2:50 PM, Michal Privoznik <mprivozn(a)redhat.com>
> wrote:
>
>> On 10/25/2017 01:53 PM, Ashish Kurian wrote:
>> > Dear Users/Developers,
>> >
>> > I am using a KVM Ubuntu VM as a degrader to apply specific delays to
>> > incoming packets. As the delay for my packets can be higher than 7.5
>> > seconds, there is not enough buffer on my interface to buffer all the
>> > packets. Therefore those overflowing packets are dropped in the
>> machine and
>> > not forwarded.
>> >
>> > When I tried to use the command ethtool -G ens8 rx 512 to increase the
>> > buffer size, I get the following error.
>> >
>> > Cannot set device ring parameters: Operation not permitted
>> >
>> > I have kept the VM xml files as specified in the link :
>> > https://libvirt.org/formatdomain.html. The value that I kept in my
>> xml file
>> > is as follows.
>> >
>> > <interface type='direct'>
>> > <mac address='52:54:00:72:f9:eb'/>
>> > <source dev='enp7s0f0' mode='vepa'/>
>> > <model type='virtio'/>
>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>> > tx_queue_size='512'>
>> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
>> ufo='off'
>> > mrg_rxbuf='off'/>
>> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
>> > </driver>
>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x08'
>> > function='0x0'/>
>> > </interface>
>> > <interface type='direct'>
>> > <mac address='52:54:00:00:b5:99'/>
>> > <source dev='enp7s0f1' mode='vepa'/>
>> > <model type='virtio'/>
>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>> > tx_queue_size='512'>
>> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
>> ufo='off'
>> > mrg_rxbuf='off'/>
>> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
>> > </driver>
>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x09'
>> > function='0x0'/>
>>
>> So what does the qemu command line look like? You can find it in either
>> libvirtd log or domain log.
>>
>> http://wiki.libvirt.org/page/DebugLogs
>>
>> Michal
>>
>
>
_______________________________________________
libvirt-users mailing list
libvirt-users(a)redhat.com
https://www.redhat.com/mailman/listinfo/libvirt-users
12:30 a.m.
Hi Yalan,
Thank you for your response. I do not have the following packages installed
vhost backend driver
qemu-kvm-rhev package
Are these packages available for free? How can I install them?
In my KVM VM, I must have an IP address to the interfaces that I am trying
to increasing the buffers. That is the reason I was using macvtap (direct
type interface). Is it possible to have my interfaces with an IP address
inside the VM to be bridged to the physical interfaces on the host?
Is it also a possibility that I change the rx and tx buffer on the physical
interface on the host and it is reflected automatically inside the VM as
you said it will always receive the default value of the host?
Best Regards,
Ashish Kurian
On Thu, Oct 26, 2017 at 6:45 AM, Yalan Zhang <yalzhang(a)redhat.com> wrote:
Hi Ashish,
I have tested with your xml in the first mail, and it works for rx_queue_size(see
below).
multiqueue need to work with vhost backend driver. And when you set
"queues=1" it will ignored.
Please check your qemu-kvm-rhev package, should be newer than
qemu-kvm-rhev-2.9.0-16.el7_4.2
And the logs?
tx_queue_size='512' will not work in the guest with direct type interface,
in fact, no matter what you set, it will not work and guest will get the
default '256'.
We only support vhost-user backend to have more than 256. refer to
https://libvirt.org/formatdomain.html#elementsNICSEthernet
tx_queue_size
The optional tx_queue_size attribute controls the size of virtio ring for
each queue as described above. The default value is hypervisor dependent
and may change across its releases. Moreover, some hypervisors may pose
some restrictions on actual value. For instance, QEMU v2.9 requires value
to be a power of two from [256, 1024] range. In addition to that, this may
work only for a subset of interface types, e.g. aforementioned QEMU enables
this option only for vhostuser type. Since 3.7.0 (QEMU and KVM only)
multiqueue only supports vhost as backend driver.
# rpm -q libvirt qemu-kvm-rhev
libvirt-3.2.0-14.el7_4.3.x86_64
qemu-kvm-rhev-2.9.0-16.el7_4.9.x86_64
1. the xml as below
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='eno1' mode='vepa'/>
<model type='virtio'/>
<driver name='vhost' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
2. after start the vm, check the qemu command line:
*-netdev
tap,fds=26:28:29:30:31,id=hostnet0,vhost=on,vhostfds=32:33:34:35:36*
-device virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=
off,host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,
guest_tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
*mq=on,vectors=12,rx_queue_size=512,tx_queue_size=512*,netdev=
hostnet0,id=net0,mac=52:54:00:00:b5:99,bus=pci.0,addr=0x3
3. check on guest
# ethtool -g eth0
Ring parameters for eth0:
Pre-set maximums:
RX: *512 ==> rx_queue_size works*
RX Mini: 0
RX Jumbo: 0
TX: *256 ===> no change*
Current hardware settings:
RX: *512 **==> rx_queue_size works*
RX Mini: 0
RX Jumbo: 0
TX: *256 ===> no change*
# ethtool -l eth0
Channel parameters for eth0:
Pre-set maximums:
RX: 0
TX: 0
Other: 0
Combined: *5 ==> queues what we set*
Current hardware settings:
RX: 0
TX: 0
Other: 0
Combined: 1
If change to qemu as driver,
# virsh edit rhel7
..
<interface type='direct'>
<mac address='52:54:00:00:b5:99'/>
<source dev='eno1' mode='vepa'/>
<model type='virtio'/>
<driver name='qemu' queues='5' rx_queue_size='512'
tx_queue_size='512'>
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
..
Domain rhel7 XML configuration edited. ==> the xml can validate and save
# virsh start rhel7
Domain rhel7 started
# virsh dumpxml rhel7 | grep /interface -B9
<source dev='eno1' mode='vepa'/>
<target dev='macvtap0'/>
<model type='virtio'/>
*<driver name='qemu' queues='5' rx_queue_size='512'
tx_queue_size='512'>*
<host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
</driver>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
* -netdev tap,fds=26:28:29:30:31*,id=hostnet0 -device
virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=
off,host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,
guest_tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
*rx_queue_size=512,tx_queue_size=512*,netdev=hostnet0,id=net0,
mac=52:54:00:00:b5:99,bus=pci.0,addr=0x3
*"mq=on,vectors=12" is missing*, indicates there is no multiqueue
and check on guest
# ethtool -l eth0
Channel parameters for eth0:
Pre-set maximums:
RX: 0
TX: 0
Other: 0
Combined: 1 ==> no multiqueue
Current hardware settings:
RX: 0
TX: 0
Other: 0
Combined: 1
# ethtool -g eth0
Ring parameters for eth0:
Pre-set maximums:
RX: *512*
RX Mini: 0
RX Jumbo: 0
TX: 256
Current hardware settings:
RX: *512*
RX Mini: 0
RX Jumbo: 0
TX: 256
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
Internal phone: 8389413
On Thu, Oct 26, 2017 at 2:33 AM, Ashish Kurian <ashishbnv(a)gmail.com>
wrote:
> Hi Michal,
>
> An update to what I have already said : when I try adding <driver
> name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off' queues='1'
> rx_queue_size='512' tx_queue_size='512'> although it showed me the
error as
> mentioned, when I checked the xml again I saw that <driver name='qemu'
> txmode='iothread' ioeventfd='on' event_idx='off' > is
added to the
> interface.
>
> The missing parameters are : queues='1' rx_queue_size='512'
> tx_queue_size='512'
>
> Best Regards,
> Ashish Kurian
>
> On Wed, Oct 25, 2017 at 5:07 PM, Ashish Kurian <ashishbnv(a)gmail.com>
> wrote:
>
>> Hi Michal,
>>
>> What I found was that when I restarted the machine and did a virsh edit
>> command to see the xml config, I see that it is was not actually changed.
>> This suggests why I saw 256 again after restarting.
>>
>> So now I tried again to edit the xml via virsh edit command and used the
>> following to set the parameters.
>>
>> <driver name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off'
>> queues='1' rx_queue_size='512' tx_queue_size='512'>
>> </driver>
>>
>> It was not accepted and I got the error saying :
>>
>>
>> error: XML document failed to validate against schema: Unable to
>> validate doc against /usr/share/libvirt/schemas/domain.rng
>> Extra element devices in interleave
>> Element domain failed to validate content
>>
>> What does this imply? I have two more other interfaces and do I have to
>> the same to them also?
>>
>> Btw, there are now logs generated now in the domain log or libvirtd log
>>
>>
>>
>>
>>
>> Best Regards,
>> Ashish Kurian
>>
>> On Wed, Oct 25, 2017 at 2:50 PM, Michal Privoznik <mprivozn(a)redhat.com>
>> wrote:
>>
>>> On 10/25/2017 01:53 PM, Ashish Kurian wrote:
>>> > Dear Users/Developers,
>>> >
>>> > I am using a KVM Ubuntu VM as a degrader to apply specific delays to
>>> > incoming packets. As the delay for my packets can be higher than 7.5
>>> > seconds, there is not enough buffer on my interface to buffer all the
>>> > packets. Therefore those overflowing packets are dropped in the
>>> machine and
>>> > not forwarded.
>>> >
>>> > When I tried to use the command ethtool -G ens8 rx 512 to increase
>>> the
>>> > buffer size, I get the following error.
>>> >
>>> > Cannot set device ring parameters: Operation not permitted
>>> >
>>> > I have kept the VM xml files as specified in the link :
>>> > https://libvirt.org/formatdomain.html. The value that I kept in my
>>> xml file
>>> > is as follows.
>>> >
>>> > <interface type='direct'>
>>> > <mac address='52:54:00:72:f9:eb'/>
>>> > <source dev='enp7s0f0' mode='vepa'/>
>>> > <model type='virtio'/>
>>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>>> > tx_queue_size='512'>
>>> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
>>> ufo='off'
>>> > mrg_rxbuf='off'/>
>>> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
>>> > </driver>
>>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x08'
>>> > function='0x0'/>
>>> > </interface>
>>> > <interface type='direct'>
>>> > <mac address='52:54:00:00:b5:99'/>
>>> > <source dev='enp7s0f1' mode='vepa'/>
>>> > <model type='virtio'/>
>>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>>> > tx_queue_size='512'>
>>> > <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
>>> ufo='off'
>>> > mrg_rxbuf='off'/>
>>> > <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
>>> > </driver>
>>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x09'
>>> > function='0x0'/>
>>>
>>> So what does the qemu command line look like? You can find it in either
>>> libvirtd log or domain log.
>>>
>>> http://wiki.libvirt.org/page/DebugLogs
>>>
>>> Michal
>>>
>>
>>
>
> _______________________________________________
> libvirt-users mailing list
> libvirt-users(a)redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
>
1:22 a.m.
Hi Ashish,
Are these packages available for free? How can I install them?
=> You did have vhost backend driver. Do not set <driver
name='qemu'...>,
by default it will use vhost as backend driver.
Is it possible to have my interfaces with an IP address inside the VM to
be bridged to the physical interfaces on the host?
=> Yes, you can create a linux bridge with physical interface connected,
and use bridge type interface. Refer to https://libvirt.org/
formatdomain.html#elementsNICSBridge
direct type is also ok (but your host and guest have no access to each
other).
Is it also a possibility that I change the rx and tx buffer on the physical
interface on the host and it is reflected automatically inside the VM as
you said it will always receive the default value of the host?
=> No, it do not receive the default value of the host. It's the default
value related with the virtual device driver on the guest.
hostdev type interface will passthrough the physical interface or VF of the
host to guest, it will get the device's parameters for rx and tx buffer.
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
Internal phone: 8389413
On Thu, Oct 26, 2017 at 1:30 PM, Ashish Kurian <ashishbnv(a)gmail.com> wrote:
Hi Yalan,
Thank you for your response. I do not have the following packages installed
vhost backend driver
qemu-kvm-rhev package
Are these packages available for free? How can I install them?
In my KVM VM, I must have an IP address to the interfaces that I am trying
to increasing the buffers. That is the reason I was using macvtap (direct
type interface). Is it possible to have my interfaces with an IP address
inside the VM to be bridged to the physical interfaces on the host?
Is it also a possibility that I change the rx and tx buffer on the
physical interface on the host and it is reflected automatically inside the
VM as you said it will always receive the default value of the host?
Best Regards,
Ashish Kurian
On Thu, Oct 26, 2017 at 6:45 AM, Yalan Zhang <yalzhang(a)redhat.com> wrote:
> Hi Ashish,
>
> I have tested with your xml in the first mail, and it works for rx_queue_size(see
> below).
> multiqueue need to work with vhost backend driver. And when you set
> "queues=1" it will ignored.
>
> Please check your qemu-kvm-rhev package, should be newer than
> qemu-kvm-rhev-2.9.0-16.el7_4.2
> And the logs?
>
> tx_queue_size='512' will not work in the guest with direct type
> interface, in fact, no matter what you set, it will not work and guest will
> get the default '256'.
> We only support vhost-user backend to have more than 256. refer to
> https://libvirt.org/formatdomain.html#elementsNICSEthernet
>
> tx_queue_size
> The optional tx_queue_size attribute controls the size of virtio ring
> for each queue as described above. The default value is hypervisor
> dependent and may change across its releases. Moreover, some hypervisors
> may pose some restrictions on actual value. For instance, QEMU v2.9
> requires value to be a power of two from [256, 1024] range. In addition to
> that, this may work only for a subset of interface types, e.g.
> aforementioned QEMU enables this option only for vhostuser type. Since
> 3.7.0 (QEMU and KVM only)
> multiqueue only supports vhost as backend driver.
>
> # rpm -q libvirt qemu-kvm-rhev
> libvirt-3.2.0-14.el7_4.3.x86_64
> qemu-kvm-rhev-2.9.0-16.el7_4.9.x86_64
>
> 1. the xml as below
> <interface type='direct'>
> <mac address='52:54:00:00:b5:99'/>
> <source dev='eno1' mode='vepa'/>
> <model type='virtio'/>
> <driver name='vhost' queues='5' rx_queue_size='512'
> tx_queue_size='512'>
> <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
> ufo='off' mrg_rxbuf='off'/>
> <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> </driver>
> <address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
> function='0x0'/>
> </interface>
>
> 2. after start the vm, check the qemu command line:
> *-netdev
> tap,fds=26:28:29:30:31,id=hostnet0,vhost=on,vhostfds=32:33:34:35:36*
> -device virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=off,
> host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,guest
> _tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
> *mq=on,vectors=12,rx_queue_size=512,tx_queue_size=512*,netdev=hostnet
> 0,id=net0,mac=52:54:00:00:b5:99,bus=pci.0,addr=0x3
>
> 3. check on guest
> # ethtool -g eth0
> Ring parameters for eth0:
> Pre-set maximums:
> RX: *512 ==> rx_queue_size works*
> RX Mini: 0
> RX Jumbo: 0
> TX: *256 ===> no change*
> Current hardware settings:
> RX: *512 **==> rx_queue_size works*
> RX Mini: 0
> RX Jumbo: 0
> TX: *256 ===> no change*
>
> # ethtool -l eth0
> Channel parameters for eth0:
> Pre-set maximums:
> RX: 0
> TX: 0
> Other: 0
> Combined: *5 ==> queues what we set*
> Current hardware settings:
> RX: 0
> TX: 0
> Other: 0
> Combined: 1
>
>
> If change to qemu as driver,
> # virsh edit rhel7
> ..
> <interface type='direct'>
> <mac address='52:54:00:00:b5:99'/>
> <source dev='eno1' mode='vepa'/>
> <model type='virtio'/>
> <driver name='qemu' queues='5' rx_queue_size='512'
> tx_queue_size='512'>
> <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
> ufo='off' mrg_rxbuf='off'/>
> <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> </driver>
> <address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
> function='0x0'/>
> </interface>
> ..
> Domain rhel7 XML configuration edited. ==> the xml can validate and save
>
> # virsh start rhel7
> Domain rhel7 started
>
>
> # virsh dumpxml rhel7 | grep /interface -B9
> <source dev='eno1' mode='vepa'/>
> <target dev='macvtap0'/>
> <model type='virtio'/>
> *<driver name='qemu' queues='5' rx_queue_size='512'
> tx_queue_size='512'>*
> <host csum='off' gso='off' tso4='off'
tso6='off' ecn='off'
> ufo='off' mrg_rxbuf='off'/>
> <guest csum='off' tso4='off' tso6='off'
ecn='off' ufo='off'/>
> </driver>
> <alias name='net0'/>
> <address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
> function='0x0'/>
> </interface>
>
>
> * -netdev tap,fds=26:28:29:30:31*,id=hostnet0 -device
> virtio-net-pci,csum=off,gso=off,host_tso4=off,host_tso6=off,
> host_ecn=off,host_ufo=off,mrg_rxbuf=off,guest_csum=off,guest
> _tso4=off,guest_tso6=off,guest_ecn=off,guest_ufo=off,
> *rx_queue_size=512,tx_queue_size=512*,netdev=hostnet0,id=net0,mac=
> 52:54:00:00:b5:99,bus=pci.0,addr=0x3
>
> *"mq=on,vectors=12" is missing*, indicates there is no multiqueue
>
> and check on guest
>
> # ethtool -l eth0
> Channel parameters for eth0:
> Pre-set maximums:
> RX: 0
> TX: 0
> Other: 0
> Combined: 1 ==> no multiqueue
> Current hardware settings:
> RX: 0
> TX: 0
> Other: 0
> Combined: 1
>
> # ethtool -g eth0
> Ring parameters for eth0:
> Pre-set maximums:
> RX: *512*
> RX Mini: 0
> RX Jumbo: 0
> TX: 256
> Current hardware settings:
> RX: *512*
> RX Mini: 0
> RX Jumbo: 0
> TX: 256
>
>
>
>
> -------
> Best Regards,
> Yalan Zhang
> IRC: yalzhang
> Internal phone: 8389413
>
> On Thu, Oct 26, 2017 at 2:33 AM, Ashish Kurian <ashishbnv(a)gmail.com>
> wrote:
>
>> Hi Michal,
>>
>> An update to what I have already said : when I try adding <driver
>> name='qemu' txmode='iothread' ioeventfd='on'
event_idx='off' queues='1'
>> rx_queue_size='512' tx_queue_size='512'> although it showed me
the error as
>> mentioned, when I checked the xml again I saw that <driver
name='qemu'
>> txmode='iothread' ioeventfd='on' event_idx='off' > is
added to the
>> interface.
>>
>> The missing parameters are : queues='1' rx_queue_size='512'
>> tx_queue_size='512'
>>
>> Best Regards,
>> Ashish Kurian
>>
>> On Wed, Oct 25, 2017 at 5:07 PM, Ashish Kurian <ashishbnv(a)gmail.com>
>> wrote:
>>
>>> Hi Michal,
>>>
>>> What I found was that when I restarted the machine and did a virsh edit
>>> command to see the xml config, I see that it is was not actually changed.
>>> This suggests why I saw 256 again after restarting.
>>>
>>> So now I tried again to edit the xml via virsh edit command and used
>>> the following to set the parameters.
>>>
>>> <driver name='qemu' txmode='iothread'
ioeventfd='on' event_idx='off'
>>> queues='1' rx_queue_size='512'
tx_queue_size='512'>
>>> </driver>
>>>
>>> It was not accepted and I got the error saying :
>>>
>>>
>>> error: XML document failed to validate against schema: Unable to
>>> validate doc against /usr/share/libvirt/schemas/domain.rng
>>> Extra element devices in interleave
>>> Element domain failed to validate content
>>>
>>> What does this imply? I have two more other interfaces and do I have to
>>> the same to them also?
>>>
>>> Btw, there are now logs generated now in the domain log or libvirtd log
>>>
>>>
>>>
>>>
>>>
>>> Best Regards,
>>> Ashish Kurian
>>>
>>> On Wed, Oct 25, 2017 at 2:50 PM, Michal Privoznik
<mprivozn(a)redhat.com>
>>> wrote:
>>>
>>>> On 10/25/2017 01:53 PM, Ashish Kurian wrote:
>>>> > Dear Users/Developers,
>>>> >
>>>> > I am using a KVM Ubuntu VM as a degrader to apply specific delays
to
>>>> > incoming packets. As the delay for my packets can be higher than
7.5
>>>> > seconds, there is not enough buffer on my interface to buffer all
the
>>>> > packets. Therefore those overflowing packets are dropped in the
>>>> machine and
>>>> > not forwarded.
>>>> >
>>>> > When I tried to use the command ethtool -G ens8 rx 512 to increase
>>>> the
>>>> > buffer size, I get the following error.
>>>> >
>>>> > Cannot set device ring parameters: Operation not permitted
>>>> >
>>>> > I have kept the VM xml files as specified in the link :
>>>> > https://libvirt.org/formatdomain.html. The value that I kept in my
>>>> xml file
>>>> > is as follows.
>>>> >
>>>> > <interface type='direct'>
>>>> > <mac address='52:54:00:72:f9:eb'/>
>>>> > <source dev='enp7s0f0' mode='vepa'/>
>>>> > <model type='virtio'/>
>>>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>>>> > tx_queue_size='512'>
>>>> > <host csum='off' gso='off'
tso4='off' tso6='off' ecn='off'
>>>> ufo='off'
>>>> > mrg_rxbuf='off'/>
>>>> > <guest csum='off' tso4='off'
tso6='off' ecn='off' ufo='off'/>
>>>> > </driver>
>>>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x08'
>>>> > function='0x0'/>
>>>> > </interface>
>>>> > <interface type='direct'>
>>>> > <mac address='52:54:00:00:b5:99'/>
>>>> > <source dev='enp7s0f1' mode='vepa'/>
>>>> > <model type='virtio'/>
>>>> > <driver name='vhost' queues='5'
rx_queue_size='512'
>>>> > tx_queue_size='512'>
>>>> > <host csum='off' gso='off'
tso4='off' tso6='off' ecn='off'
>>>> ufo='off'
>>>> > mrg_rxbuf='off'/>
>>>> > <guest csum='off' tso4='off'
tso6='off' ecn='off' ufo='off'/>
>>>> > </driver>
>>>> > <address type='pci' domain='0x0000'
bus='0x00' slot='0x09'
>>>> > function='0x0'/>
>>>>
>>>> So what does the qemu command line look like? You can find it in either
>>>> libvirtd log or domain log.
>>>>
>>>> http://wiki.libvirt.org/page/DebugLogs
>>>>
>>>> Michal
>>>>
>>>
>>>
>>
>> _______________________________________________
>> libvirt-users mailing list
>> libvirt-users(a)redhat.com
>> https://www.redhat.com/mailman/listinfo/libvirt-users
>>
>
>
2619
days inactive
2620
days old
6 comments
3 participants
participants (3)
-
Ashish Kurian -
Michal Privoznik -
Yalan Zhang