Re: [PATCH 4/7] KVM: SVM: hyper-v: Nested enlightenments in VMCB

[Paolo Bonzini <pbonzini@xxxxxxxxxx>]

On 07/04/21 16:41, Vineeth Pillai wrote:
> +#define VMCB_ALL_CLEAN_MASK (__CLEAN_MASK | (1U << VMCB_HV_NESTED_ENLIGHTENMENTS))
> +#else
> +#define VMCB_ALL_CLEAN_MASK __CLEAN_MASK
> +#endif

I think this should depend on whether KVM is running on top of Hyper-V; 
not on whether KVM is *compiled* with Hyper-V support.

So you should turn VMCB_ALL_CLEAN_MASK into a __read_mostly variable.

Paolo

>   /* TPR and CR2 are always written before VMRUN */
>   #define VMCB_ALWAYS_DIRTY_MASK	((1U << VMCB_INTR) | (1U << VMCB_CR2))
>   
> @@ -230,7 +251,7 @@ static inline void vmcb_mark_all_dirty(struct vmcb *vmcb)
>   
>   static inline void vmcb_mark_all_clean(struct vmcb *vmcb)
>   {
> -	vmcb->control.clean = ((1 << VMCB_DIRTY_MAX) - 1)
> +	vmcb->control.clean = VMCB_ALL_CLEAN_MASK
>   			       & ~VMCB_ALWAYS_DIRTY_MASK;
>   }