Bheve: Slow linux syscalls on AMD

Willem Jan Withagen wjw at
Sat May 31 00:37:58 UTC 2014

On 31-5-2014 2:13, Peter Grehan wrote:
> Hi Willem,
>> So the question remains:
>>     Why is it taking so long on the AMD platform.
>  The time difference looks a lot like a VM-exit roundtrip. My new AMD
> box is arriving shortly so I'll have a look into it.

Hi Peter,

I would expect something like this.
The question however what kind of business is done during the roundtrip.
Could it be something like a soft-interrupt 0x80 to get from userspace
to the kernel? Supossedly this interface is depreciated around 2.4

I'll see if I can augment the exit-code in bhyve.
Catching it with bhyvectl --get-all will probably have too much noise
from running the rest of the system.


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