RE: [PATCH v3] x86/hyper-v: Mark TLFS structures packed

[Michael Kelley]

From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>  Sent: Monday, December 3, 2018 6:07 AM
>
> The TLFS structures are used for hypervisor-guest communication and must
> exactly meet the specification.
> 
> Compilers can add alignment padding to structures or reorder struct members
> for randomization and optimization, which would break the hypervisor ABI.
> 
> Mark the structures as packed to prevent this.
> 
> Suggested-by: Nadav Amit <nadav.amit@xxxxxxxxx>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Acked-by: Nadav Amit <nadav.amit@xxxxxxxxx>
> ---
> - Changes since v2:
>  - add __packed to struct 'u' defined within union 'hv_port_id'
>    [Michael Kelley]
> 
> - This is a follow-up to my "[PATCH v2 0/4] x86/kvm/hyper-v: Implement
>  Direct Mode for synthetic timers" series, as suggested by Thomas I'm
>  routing it to KVM tree to avoid merge conflicts.
> ---

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>