Re: [PATCH] Add Documentation/kvm/msr.txt

[Glauber Costa <glommer@redhat.com>]

On Sun, May 30, 2010 at 12:14:21PM +0300, Avi Kivity wrote:
> On 05/27/2010 07:02 PM, Glauber Costa wrote:
> >>
> >>>+
> >>>+Custom MSR list
> >>>+--------
> >>>+
> >>>+The current supported Custom MSR list is:
> >>>+
> >>>+MSR_KVM_WALL_CLOCK:  0x11
> >>>+
> >>>+	data: physical address of a memory area.
> >>Which must be in guest RAM (i.e., don't point it somewhere random
> >>and expect the hypervisor to allocate it for you).
> >>
> >>Must be aligned to 4 bytes (we don't enforce it though).
> >I don't see the reason for it.
> 
> Insurance.
> 
> >If this is a requirement, our own implementation
> >is failing to meet it.
> 
> How are we failing to meet it?  All guests align to at least four bytes.
static struct pvclock_wall_clock wall_clock;

Unless there is something that the compiler does that I should take for granted,
there is no alignment directive in there, and it could be anywhere.