lkml.org 
[lkml]   [2007]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [kvm-devel] [PATCH 0/15] KVM userspace interface updates
Heiko Carstens wrote:
>>>
>>>
>> What benefit would a syscall interface have?
>>
>
> Another thing is that this patch set already introduces a way to pass a
> sigset. Passing a sigset to a device node is sort of strange.
>

The sigset is passed to the device node just for safekeeping, as it
doesn't normally change. It's only used when switching to guest mode.

> In addition, if we would port kvm to s390, then we would need to
> make sure that each virtual cpu only gets executed from the thread
> that created it. That is simply because the upper half of our page
> tables contain information about the guest page states. This is yet
> another thing that would be strange to do via an ioctl based interface.
>

Right. I agree it's more natural to associate a vcpu with a task
instead of a vcpu being an independent entry. We'd still need a handle
for it, and in Linux that's an fd (pid doesn't cut it as it's racy, and
probably slower too as it has to go through a global structure).

> Of course everthing can be done via an iotcl interface too, but IMHO
> that's just the wrong interface.
>

I guess once we have smp, and preferably an additional arch port, we can
do another round of API consolidation around a syscall based API. We'll
need to support the ioctl based API in parallel until the distros flush
out older userspace.

--
error compiling committee.c: too many arguments to function

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-03-18 11:45    [W:0.049 / U:1.096 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site