Re: [PATCH v2] xen/x86: Identify which vcpu's CR4 is being badly modified

[Andrew Cooper <andrew.cooper3@citrix.com>]

Please ignore this - I appear to have gained the new patch message with
the old patch.  I shall try to correct.

~Andrew

On 26/03/14 14:00, Andrew Cooper wrote:
> When the toolstack is setting vcpu state on behalf of a migrating guest, the
> domain/vcpu reference from gdprintk() identifies the toolstack, not the
> affected domain.
>
> After this change, the error looks more like:
>
>   (XEN) d0 attempted to change d6v0's CR4 flags 00002660 -> 01876000
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> CC: Keir Fraser <keir@xen.org>
> CC: Jan Beulich <JBeulich@suse.com>
>
> ---
> v2: gdprintk -> printk, drop current's vcpu reference.
> ---
>  xen/arch/x86/domain.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index b48f2dc..59e2729 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -652,8 +652,8 @@ unsigned long pv_guest_cr4_fixup(const struct vcpu *v, unsigned long guest_cr4)
>  
>      if ( (guest_cr4 & hv_cr4_mask) != (hv_cr4 & hv_cr4_mask) )
>          gdprintk(XENLOG_WARNING,
> -                 "Attempt to change CR4 flags %08lx -> %08lx\n",
> -                 hv_cr4, guest_cr4);
> +                 "Attempt to change %pv's CR4 flags %08lx -> %08lx\n",
> +                 v, hv_cr4, guest_cr4);
>  
>      return (hv_cr4 & hv_cr4_mask) | (guest_cr4 & ~hv_cr4_mask);
>  }