Re: [PATCH 2/3] x86/mtrr: move epte_get_entry_emt to p2m-ept.c

[Jan Beulich <jbeulich@suse.com>]

On 28.05.2021 19:39, Roger Pau Monne wrote:
> This is an EPT specific function, so it shouldn't live in the generic
> mtrr file. Such movement is also needed for future work that will
> require passing a p2m_type_t parameter to epte_get_entry_emt, and
> making that type visible to the mtrr users is cumbersome and
> unneeded.
> 
> Moving epte_get_entry_emt out of mtrr.c requires making the helper to
> get the MTRR type of an address from the mtrr state public. While
> there rename the function to start with the mtrr prefix, like other
> mtrr related functions.
> 
> While there fix some of the types of the function parameters.
> 
> No functional change intended.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>

> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -417,12 +417,12 @@ static int vmx_domain_initialise(struct domain *d)
>  static void domain_creation_finished(struct domain *d)
>  {
>      gfn_t gfn = gaddr_to_gfn(APIC_DEFAULT_PHYS_BASE);
> -    uint8_t ipat;
> +    bool ipat;
>  
>      if ( !has_vlapic(d) || mfn_eq(apic_access_mfn, INVALID_MFN) )
>          return;
>  
> -    ASSERT(epte_get_entry_emt(d, gfn_x(gfn), apic_access_mfn, 0, &ipat,
> +    ASSERT(epte_get_entry_emt(d, gfn, apic_access_mfn, 0, &ipat,
>                                true) == MTRR_TYPE_WRBACK);
>      ASSERT(ipat);

This being the only reason for the function to not be static in
p2m-ept.c, I wonder whether it's really worthwhile to keep these
assertions. But certainly not directly related to change at hand.

Jan