Re: KVM performance

[Randy Broman <rbroman@bayarea.net>]

After I submitted the initial question, I downloaded the latest kernel 
2.6.27.6, and compiled
with the following options, some of which are new since my previous 
kernel 2.6.24-21.

CONFIG_PARAVIRT_GUEST=y
CONFIG_XEN_SAVE_RESTORE=y
CONFIG_VMI=y
CONFIG_KVM_CLOCK=y
CONFIG_KVM_GUEST=y
# CONFIG_LGUEST_GUEST is not set
CONFIG_PARAVIRT=y
CONFIG_PARAVIRT_CLOCK=y

Using my existing kvm-62 and the following invocation:

$ aoss kvm -m 1024 -cdrom /dev/cdrom -boot c -net 
nic,macaddr=00:d0:13:b0:2d:32,model=rtl8139 -net tap -soundhw all 
-localtime /home/rbroman/windows.img

CPU usage went down and performance was much better (no skips), for my 
video/audio feeds.

I then downloaded, compiled, installed kvm-79, and invoked using the 
following options

$ aoss ~/kvm-79/kvm -m 1024 --cdrom /dev/cdrom --mac=00:d0:13:b0:2d:32 
--nictype=rtl8139 --smp=2 /home/rbroman/windows.img

Note I'm using the new kvm in the compile directory, and I've confirmed 
that the kvm and kvm-intel
modules from the kvm-79 compile are what's loaded. Some of the options 
from the kvm-62 invocation
are missing - because they give errors - I understand that the command 
syntax/options have changed,
and I've checked ~/kvm-79/kvm --help for the new syntax, but I can't 
figure out how to invoke the
remaining options. One of the missing options seems to be the tap 
network, and the kvm-79 WinXP
guest now has no networking.

I also tried the "-vga vmware" option below, as well as -vga=vmware and 
various other permutations,
and I can't get that to work either.

Can someone help me resolve the above? Are there any README's, HowTo's 
or other documentation
on compiling, installing and using kvm-79?

Thanks, Randy

Avi Kivity wrote:
> Randy Broman wrote:
>>
>> -I've tried both the default Cirrus adapter and the "-std-vga" 
>> option. Which is better?
>
> Cirrus is generally better, but supports fewer resolutions.
>
>> I saw reference to another VMware-based adapter, but I can't figure 
>> out how to implement
>> it - would that be better?
>>
>
> -vga vmware (with the new syntax needed by kvm-79); it should be 
> better, but is less will tested.  I'm not at all sure the Windows 
> driver will like it.
>
>> -I notice we're up to kvm-79 vs my kvm-62. Should I move to the newer 
>> version? 
>
> Yes.
>
>> Do I
>> have to custom-compile my kernel to do so
>
> No.
>