Re: [XEN][PATCH] x86/hvm: move hvm_shadow_handle_cd() under CONFIG_INTEL_VMX ifdef

[Jan Beulich <jbeulich@xxxxxxxx>]

On 23.10.2025 17:19, Grygorii Strashko wrote:
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -2168,30 +2168,6 @@ int hvm_set_efer(uint64_t value)
>      return X86EMUL_OKAY;
>  }
>  
> -/* Exit UC mode only if all VCPUs agree on MTRR/PAT and are not in no_fill. 
> */
> -static bool domain_exit_uc_mode(struct vcpu *v)
> -{
> -    struct domain *d = v->domain;
> -    struct vcpu *vs;
> -
> -    for_each_vcpu ( d, vs )
> -    {
> -        if ( (vs == v) || !vs->is_initialised )
> -            continue;
> -        if ( (vs->arch.hvm.cache_mode == NO_FILL_CACHE_MODE) ||
> -             mtrr_pat_not_equal(vs, v) )
> -            return 0;
> -    }
> -
> -    return 1;
> -}
> -
> -static void hvm_set_uc_mode(struct vcpu *v, bool is_in_uc_mode)
> -{
> -    v->domain->arch.hvm.is_in_uc_mode = is_in_uc_mode;
> -    shadow_blow_tables_per_domain(v->domain);
> -}
> -
>  int hvm_mov_to_cr(unsigned int cr, unsigned int gpr)
>  {
>      struct vcpu *curr = current;
> @@ -2273,6 +2249,31 @@ int hvm_mov_from_cr(unsigned int cr, unsigned int gpr)
>      return X86EMUL_UNHANDLEABLE;
>  }
>  
> +#ifdef CONFIG_INTEL_VMX
> +/* Exit UC mode only if all VCPUs agree on MTRR/PAT and are not in no_fill. 
> */
> +static bool domain_exit_uc_mode(struct vcpu *v)
> +{
> +    struct domain *d = v->domain;
> +    struct vcpu *vs;
> +
> +    for_each_vcpu ( d, vs )
> +    {
> +        if ( (vs == v) || !vs->is_initialised )
> +            continue;
> +        if ( (vs->arch.hvm.cache_mode == NO_FILL_CACHE_MODE) ||
> +             mtrr_pat_not_equal(vs, v) )
> +            return 0;
> +    }
> +
> +    return 1;
> +}
> +
> +static void hvm_set_uc_mode(struct vcpu *v, bool is_in_uc_mode)
> +{
> +    v->domain->arch.hvm.is_in_uc_mode = is_in_uc_mode;
> +    shadow_blow_tables_per_domain(v->domain);
> +}
> +
>  void hvm_shadow_handle_cd(struct vcpu *v, unsigned long value)

In addition to what others have said, as we're talking of unreachable code
here: This function also is unreachable when SHADOW_PAGING=n. If already
you make adjustments, I think you want to cover this other aspect at the
same time.

Jan