Re: [PATCH 1/2] x86/mem_sharing: copy cpuid during vm forking

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 04/01/2021 17:41, Tamas K Lengyel wrote:
> Signed-off-by: Tamas K Lengyel <tamas.lengyel@xxxxxxxxx>
> ---
>  xen/arch/x86/mm/mem_sharing.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
> index c428fd16ce..4a02c7d6f2 100644
> --- a/xen/arch/x86/mm/mem_sharing.c
> +++ b/xen/arch/x86/mm/mem_sharing.c
> @@ -1764,6 +1764,7 @@ static int fork(struct domain *cd, struct domain *d)
>  
>          domain_pause(d);
>          cd->max_pages = d->max_pages;
> +        memcpy(cd->arch.cpuid, d->arch.cpuid, sizeof(*d->arch.cpuid));
>          cd->parent = d;
>      }
>  

You need to extend this to d->arch.msr and v->arch.msrs or someone is
going to have a very subtle bug to debug in the future.

~Andrew