Stop the clock!

Stop the clock!

[Avi Kivity]

With paravirt clocksource, reboot and kexec are broken: the clock keeps 
updating after the reboot, and the new kernel will have a random memory 
location trampled occasionally.

So we need to stop the clock on kexec (in the guest) and reboot (in the 
host).  On the host side, this can be done either in the kernel, or in 
userspace via new ioctls.

Joerg, I think you mentioned you were working on a vm-wide reset 
ioctl()?  If so, that would be the place to stop the clock on reboot.

Glauber, can you extend the interface to support stopping the clock?  It 
needs to be done even outside kexec, for example if the the user decides 
to stop using your clock.

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


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Re: Stop the clock!

[Glauber Costa]

Avi Kivity wrote:
> With paravirt clocksource, reboot and kexec are broken: the clock keeps 
> updating after the reboot, and the new kernel will have a random memory 
> location trampled occasionally.
> 
> So we need to stop the clock on kexec (in the guest) and reboot (in the 
> host).  On the host side, this can be done either in the kernel, or in 
> userspace via new ioctls.
> 
> Joerg, I think you mentioned you were working on a vm-wide reset 
> ioctl()?  If so, that would be the place to stop the clock on reboot.
> 
> Glauber, can you extend the interface to support stopping the clock?  It 
> needs to be done even outside kexec, for example if the the user decides 
> to stop using your clock.
> 
Sure, I'll work on it.

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Re: Stop the clock!

[Joerg Roedel]

On Tue, Mar 04, 2008 at 12:47:58PM +0200, Avi Kivity wrote:
> With paravirt clocksource, reboot and kexec are broken: the clock keeps updating after the reboot, and the new kernel will have a random memory location trampled occasionally.
> 
> So we need to stop the clock on kexec (in the guest) and reboot (in the host).  On the host side, this can be done either in the kernel, or in userspace via new ioctls.
> 
> Joerg, I think you mentioned you were working on a vm-wide reset ioctl()?  If so, that would be the place to stop the clock on reboot.
> 
> Glauber, can you extend the interface to support stopping the clock?  It needs to be done even outside kexec, for example if the the user decides to stop using your clock.

Yes, I am working on that ioctl(), but don't expect a patch this week
because I am busy with an other task temporarily.

Joerg

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