RE: [PATCH] IOMMU/x86: tidy adjust_irq_affinities hook

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Jan Beulich <jbeulich@xxxxxxxx>
> Sent: Monday, March 7, 2022 8:40 PM
> 
> As of 3e56754b0887 ("xen/cet: Fix __initconst_cf_clobber") there's no
> need for a non-void return value anymore, as the hook functions are no
> longer themselves passed to __initcall(). For the same reason the
> iommu_enabled checks can now move from the individual functions to the
> wrapper.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>

> 
> --- a/xen/arch/x86/include/asm/iommu.h
> +++ b/xen/arch/x86/include/asm/iommu.h
> @@ -101,11 +101,10 @@ void iommu_update_ire_from_apic(unsigned
>  unsigned int iommu_read_apic_from_ire(unsigned int apic, unsigned int reg);
>  int iommu_setup_hpet_msi(struct msi_desc *);
> 
> -static inline int iommu_adjust_irq_affinities(void)
> +static inline void iommu_adjust_irq_affinities(void)
>  {
> -    return iommu_ops.adjust_irq_affinities
> -           ? iommu_call(&iommu_ops, adjust_irq_affinities)
> -           : 0;
> +    if ( iommu_enabled && iommu_ops.adjust_irq_affinities )
> +        iommu_vcall(&iommu_ops, adjust_irq_affinities);
>  }
> 
>  static inline bool iommu_supports_x2apic(void)
> --- a/xen/drivers/passthrough/amd/iommu.h
> +++ b/xen/drivers/passthrough/amd/iommu.h
> @@ -234,7 +234,7 @@ int amd_iommu_prepare(bool xt);
>  int amd_iommu_init(bool xt);
>  int amd_iommu_init_late(void);
>  int amd_iommu_update_ivrs_mapping_acpi(void);
> -int cf_check iov_adjust_irq_affinities(void);
> +void cf_check iov_adjust_irq_affinities(void);
> 
>  int cf_check amd_iommu_quarantine_init(struct domain *d);
> 
> --- a/xen/drivers/passthrough/amd/iommu_init.c
> +++ b/xen/drivers/passthrough/amd/iommu_init.c
> @@ -809,13 +809,10 @@ static bool_t __init set_iommu_interrupt
>      return 1;
>  }
> 
> -int cf_check iov_adjust_irq_affinities(void)
> +void cf_check iov_adjust_irq_affinities(void)
>  {
>      const struct amd_iommu *iommu;
> 
> -    if ( !iommu_enabled )
> -        return 0;
> -
>      for_each_amd_iommu ( iommu )
>      {
>          struct irq_desc *desc = irq_to_desc(iommu->msi.irq);
> @@ -828,8 +825,6 @@ int cf_check iov_adjust_irq_affinities(v
>              set_msi_affinity(desc, NULL);
>          spin_unlock_irqrestore(&desc->lock, flags);
>      }
> -
> -    return 0;
>  }
> 
>  /*
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -2107,17 +2107,12 @@ static void adjust_irq_affinity(struct a
>      spin_unlock_irqrestore(&desc->lock, flags);
>  }
> 
> -static int cf_check adjust_vtd_irq_affinities(void)
> +static void cf_check adjust_vtd_irq_affinities(void)
>  {
>      struct acpi_drhd_unit *drhd;
> 
> -    if ( !iommu_enabled )
> -        return 0;
> -
>      for_each_drhd_unit ( drhd )
>          adjust_irq_affinity(drhd);
> -
> -    return 0;
>  }
> 
>  static int __must_check init_vtd_hw(bool resume)
> --- a/xen/drivers/passthrough/x86/iommu.c
> +++ b/xen/drivers/passthrough/x86/iommu.c
> @@ -464,7 +464,9 @@ bool arch_iommu_use_permitted(const stru
> 
>  static int __init cf_check adjust_irq_affinities(void)
>  {
> -    return iommu_adjust_irq_affinities();
> +    iommu_adjust_irq_affinities();
> +
> +    return 0;
>  }
>  __initcall(adjust_irq_affinities);
> 
> --- a/xen/include/xen/iommu.h
> +++ b/xen/include/xen/iommu.h
> @@ -267,7 +267,7 @@ struct iommu_ops {
> 
>      int (*setup_hpet_msi)(struct msi_desc *);
> 
> -    int (*adjust_irq_affinities)(void);
> +    void (*adjust_irq_affinities)(void);
>      void (*clear_root_pgtable)(struct domain *d);
>      int (*update_ire_from_msi)(struct msi_desc *msi_desc, struct msi_msg
> *msg);
>  #endif /* CONFIG_X86 */