RE: [PATCH v2 8/9] x86/hyperv: Set realmode_limit to 4G for VTL2 TDX guest

[Michael Kelley]

From: Yunhong Jiang <yunhong.jiang@xxxxxxxxxxxxxxx>
> 
> The VTL2 TDX guest may have no sub-1M memory available, but it needs to
> invoke trampoline_start64 to wake up the APs through the wakeup mailbox
> mechanism. Set realmode_limit to 4G for the VTL2 TDX guest, so that
> reserve_real_mode allocae memory under 4G.

s/allocate/allocate/

Michael

> 
> Signed-off-by: Yunhong Jiang <yunhong.jiang@xxxxxxxxxxxxxxx>
> ---
>  arch/x86/hyperv/hv_vtl.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
> index e5aa2688cdd0..5829aac74f80 100644
> --- a/arch/x86/hyperv/hv_vtl.c
> +++ b/arch/x86/hyperv/hv_vtl.c
> @@ -40,11 +40,15 @@ void __init hv_vtl_init_platform(void)
>  {
>  	pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
> 
> -	if (hv_isolation_type_tdx())
> +	if (hv_isolation_type_tdx()) {
>  		x86_platform.hyper.is_private_mmio = hv_is_private_mmio_tdx;
> -	x86_platform.realmode_reserve = x86_init_noop;
> -	x86_platform.realmode_init = x86_init_noop;
> -	real_mode_header = &hv_vtl_real_mode_header;
> +		x86_init.resources.realmode_limit = SZ_4G;
> +		x86_init.resources.reserve_bios = 0;
> +	} else {
> +		x86_platform.realmode_reserve = x86_init_noop;
> +		x86_platform.realmode_init = x86_init_noop;
> +		real_mode_header = &hv_vtl_real_mode_header;
> +	}
>  	x86_init.irqs.pre_vector_init = x86_init_noop;
>  	x86_init.timers.timer_init = x86_init_noop;
> 
> --
> 2.25.1
>