Re: [PATCH 2/3] x86/boot: Don't enable EFER.SCE for !CONFIG_PV builds

[Jan Beulich <jbeulich@xxxxxxxx>]

On 20.04.2020 16:59, Andrew Cooper wrote:
> --- a/xen/arch/x86/efi/efi-boot.h
> +++ b/xen/arch/x86/efi/efi-boot.h
> @@ -238,7 +238,8 @@ static void __init noreturn efi_arch_post_exit_boot(void)
>      /* Set system registers and transfer control. */
>      asm volatile("pushq $0\n\tpopfq");
>      rdmsrl(MSR_EFER, efer);
> -    efer |= EFER_SCE;
> +    if ( IS_ENABLED(CONFIG_PV) )
> +        efer |= EFER_SCE;
>      if ( cpu_has_nx )
>          efer |= EFER_NX;
>      wrmsrl(MSR_EFER, efer);

Switch to simply ORing in trampoline_efer here?

With or without the adjustment
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan