Re: [PATCH 5/6] x86/mm: the gva_to_gfn() hook is HVM-only

[Jan Beulich <jbeulich@suse.com>]

On 15.12.2020 17:27, Jan Beulich wrote:
> As is the adjacent ga_to_gfn() one as well as paging_gva_to_gfn().
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -1772,7 +1772,6 @@ void np2m_schedule(int dir)
>          p2m_unlock(p2m);
>      }
>  }
> -#endif
>  
>  unsigned long paging_gva_to_gfn(struct vcpu *v,
>                                  unsigned long va,
> @@ -1820,6 +1819,8 @@ unsigned long paging_gva_to_gfn(struct v
>      return hostmode->gva_to_gfn(v, hostp2m, va, pfec);
>  }
>  
> +#endif /* CONFIG_HVM */
> +
>  /*
>   * If the map is non-NULL, we leave this function having acquired an extra ref
>   * on mfn_to_page(*mfn).  In all cases, *pfec contains appropriate
> --- a/xen/arch/x86/mm/shadow/multi.c
> +++ b/xen/arch/x86/mm/shadow/multi.c
> @@ -3414,6 +3414,7 @@ static bool sh_invlpg(struct vcpu *v, un
>      return true;
>  }
>  
> +#ifdef CONFIG_HVM
>  
>  static unsigned long
>  sh_gva_to_gfn(struct vcpu *v, struct p2m_domain *p2m,
> @@ -3447,6 +3448,7 @@ sh_gva_to_gfn(struct vcpu *v, struct p2m
>      return gfn_x(gfn);
>  }
>  
> +#endif /* CONFIG_HVM */
>  
>  static inline void
>  sh_update_linear_entries(struct vcpu *v)
> @@ -4571,7 +4573,9 @@ int sh_audit_l4_table(struct vcpu *v, mf
>  const struct paging_mode sh_paging_mode = {
>      .page_fault                    = sh_page_fault,
>      .invlpg                        = sh_invlpg,
> +#ifdef CONFIG_HVM
>      .gva_to_gfn                    = sh_gva_to_gfn,
> +#endif
>      .update_cr3                    = sh_update_cr3,
>      .update_paging_modes           = shadow_update_paging_modes,
>      .flush_tlb                     = shadow_flush_tlb,

I've noticed (or really the compiler told me) I forgot to also
change none.c:

--- a/xen/arch/x86/mm/shadow/none.c
+++ b/xen/arch/x86/mm/shadow/none.c
@@ -43,12 +43,14 @@ static bool _invlpg(struct vcpu *v, unsi
     return true;
 }
 
+#ifdef CONFIG_HVM
 static unsigned long _gva_to_gfn(struct vcpu *v, struct p2m_domain *p2m,
                                  unsigned long va, uint32_t *pfec)
 {
     ASSERT_UNREACHABLE();
     return gfn_x(INVALID_GFN);
 }
+#endif
 
 static void _update_cr3(struct vcpu *v, int do_locking, bool noflush)
 {
@@ -63,7 +65,9 @@ static void _update_paging_modes(struct
 static const struct paging_mode sh_paging_none = {
     .page_fault                    = _page_fault,
     .invlpg                        = _invlpg,
+#ifdef CONFIG_HVM
     .gva_to_gfn                    = _gva_to_gfn,
+#endif
     .update_cr3                    = _update_cr3,
     .update_paging_modes           = _update_paging_modes,
 };

Jan

> --- a/xen/include/asm-x86/paging.h
> +++ b/xen/include/asm-x86/paging.h
> @@ -127,6 +127,7 @@ struct paging_mode {
>                                              struct cpu_user_regs *regs);
>      bool          (*invlpg                )(struct vcpu *v,
>                                              unsigned long linear);
> +#ifdef CONFIG_HVM
>      unsigned long (*gva_to_gfn            )(struct vcpu *v,
>                                              struct p2m_domain *p2m,
>                                              unsigned long va,
> @@ -136,6 +137,7 @@ struct paging_mode {
>                                              unsigned long cr3,
>                                              paddr_t ga, uint32_t *pfec,
>                                              unsigned int *page_order);
> +#endif
>      void          (*update_cr3            )(struct vcpu *v, int do_locking,
>                                              bool noflush);
>      void          (*update_paging_modes   )(struct vcpu *v);
> @@ -286,6 +288,8 @@ unsigned long paging_gva_to_gfn(struct v
>                                  unsigned long va,
>                                  uint32_t *pfec);
>  
> +#ifdef CONFIG_HVM
> +
>  /* Translate a guest address using a particular CR3 value.  This is used
>   * to by nested HAP code, to walk the guest-supplied NPT tables as if
>   * they were pagetables.
> @@ -304,6 +308,8 @@ static inline unsigned long paging_ga_to
>          page_order);
>  }
>  
> +#endif /* CONFIG_HVM */
> +
>  /* Update all the things that are derived from the guest's CR3.
>   * Called when the guest changes CR3; the caller can then use v->arch.cr3
>   * as the value to load into the host CR3 to schedule this vcpu */
> 
>