Re: [XEN PATCH v1 2/3] x86/hvm: introduce config option for stdvga emulation

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Fri, Oct 04, 2024 at 12:33:53PM +0300, Sergiy Kibrik wrote:
> Introduce config option X86_STDVGA so that stdvga emulation driver can later 
> be
> made configurable and be disabled on systems that don't need it.
> 
> As a first step the option is hidden from user. No functional changes 
> intended.
> 
> Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
> CC: Jan Beulich <jbeulich@xxxxxxxx>
> ---
>  xen/arch/x86/Kconfig              | 3 +++
>  xen/arch/x86/hvm/Makefile         | 2 +-
>  xen/arch/x86/include/asm/domain.h | 3 ++-
>  xen/arch/x86/include/asm/hvm/io.h | 4 ++++
>  4 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
> index 95275dc17e..89c42ff6da 100644
> --- a/xen/arch/x86/Kconfig
> +++ b/xen/arch/x86/Kconfig
> @@ -147,6 +147,9 @@ config INTEL_VMX
>  config X86_PMTIMER
>       def_bool HVM
>  
> +config X86_STDVGA
> +     def_bool HVM

Same as previous patch, the content of patch 3 needs to be moved here.

> +
>  config XEN_SHSTK
>       bool "Supervisor Shadow Stacks"
>       depends on HAS_AS_CET_SS
> diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
> index 321241f0bf..b7741b0f60 100644
> --- a/xen/arch/x86/hvm/Makefile
> +++ b/xen/arch/x86/hvm/Makefile
> @@ -22,7 +22,7 @@ obj-$(CONFIG_X86_PMTIMER) += pmtimer.o
>  obj-y += quirks.o
>  obj-y += rtc.o
>  obj-y += save.o
> -obj-y += stdvga.o
> +obj-$(CONFIG_X86_STDVGA) += stdvga.o
>  obj-y += vioapic.o
>  obj-y += vlapic.o
>  obj-y += vm_event.o
> diff --git a/xen/arch/x86/include/asm/domain.h 
> b/xen/arch/x86/include/asm/domain.h
> index 3f65bfd190..675a13d917 100644
> --- a/xen/arch/x86/include/asm/domain.h
> +++ b/xen/arch/x86/include/asm/domain.h
> @@ -501,7 +501,8 @@ struct arch_domain
>  #define has_vrtc(d)        (!!((d)->arch.emulation_flags & X86_EMU_RTC))
>  #define has_vioapic(d)     (!!((d)->arch.emulation_flags & X86_EMU_IOAPIC))
>  #define has_vpic(d)        (!!((d)->arch.emulation_flags & X86_EMU_PIC))
> -#define has_vvga(d)        (!!((d)->arch.emulation_flags & X86_EMU_VGA))
> +#define has_vvga(d)        (IS_ENABLED(CONFIG_X86_STDVGA) && \

You don't need the IS_ENABLED() if emulation_flags_ok() is adjusted
accordingly.

Thanks, Roger.