Re: [PATCH v2 3/3] [FUTURE] xen/arm: enable vPCI for domUs

[Julien Grall <julien@xxxxxxx>]

Hi,

On 07/07/2023 02:47, Stewart Hildebrand wrote:
> Remove is_hardware_domain check in has_vpci, and select HAS_VPCI_GUEST_SUPPORT
> in Kconfig.
>
> [1] https://lists.xenproject.org/archives/html/xen-devel/2023-06/msg00863.html
>
> Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx>
> ---
> As the tag implies, this patch is not intended to be merged (yet).
Can this be included in the vPCI series or resent afterwards?

> Note that CONFIG_HAS_VPCI_GUEST_SUPPORT is not currently used in the upstream
> code base. It will be used by the vPCI series [1]. This patch is intended to be
> merged as part of the vPCI series.
>
> v1->v2:
> * new patch
> ---
>   xen/arch/arm/Kconfig              | 1 +
>   xen/arch/arm/include/asm/domain.h | 2 +-
>   2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index 4e0cc421ad48..75dfa2f5a82d 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -195,6 +195,7 @@ config PCI_PASSTHROUGH
>         depends on ARM_64
>         select HAS_PCI
>         select HAS_VPCI
> +       select HAS_VPCI_GUEST_SUPPORT
>         default n
>         help
>           This option enables PCI device passthrough
> diff --git a/xen/arch/arm/include/asm/domain.h 
> b/xen/arch/arm/include/asm/domain.h
> index 1a13965a26b8..6e016b00bae1 100644
> --- a/xen/arch/arm/include/asm/domain.h
> +++ b/xen/arch/arm/include/asm/domain.h
> @@ -298,7 +298,7 @@ static inline void arch_vcpu_block(struct vcpu *v) {}
>   
>   #define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag)
>   
> -#define has_vpci(d) ({ IS_ENABLED(CONFIG_HAS_VPCI) && is_hardware_domain(d); })
> +#define has_vpci(d)    ({ (void)(d); IS_ENABLED(CONFIG_HAS_VPCI); })
As I mentioned in the previous patch, wouldn't this enable vPCI 
unconditionally for all the domain? Shouldn't this be instead an 
optional feature which would be selected by the toolstack?
Cheers,

--
Julien Grall