RE: [RFC Patch v2 1/4] x86/Hyper-V: Not use hv apic driver when Secure AVIC is available

[Michael Kelley]

From: Tianyu Lan <ltykernel@xxxxxxxxx> Sent: Friday, June 13, 2025 4:08 AM
> 
> From: Tianyu Lan <tiala@xxxxxxxxxxxxx>

The for the patch Subject line, use "x86/hyperv:" as the prefix. Also,
I would suggest better wording. So:

x86/hyperv: Don't use the Hyper-V APIC driver when Secure AVIC is available

> 
> When Secure AVIC is available, AMD x2apic Secure
> AVIC driver should be selected and return directly
> in the hv_apic_init().

Better wording:

When Secure AVIC is available, the AMD x2apic Secure
AVIC driver will be selected. In that case, have hv_apic_init()
return immediately without doing anything.

> 
> Signed-off-by: Tianyu Lan <tiala@xxxxxxxxxxxxx>
> ---
>  arch/x86/hyperv/hv_apic.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
> index bfde0a3498b9..1c48396e5389 100644
> --- a/arch/x86/hyperv/hv_apic.c
> +++ b/arch/x86/hyperv/hv_apic.c
> @@ -293,6 +293,9 @@ static void hv_send_ipi_self(int vector)
> 
>  void __init hv_apic_init(void)
>  {
> +       if (cc_platform_has(CC_ATTR_SNP_SECURE_AVIC))
> +               return;
> +
>  	if (ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) {
>  		pr_info("Hyper-V: Using IPI hypercalls\n");
>  		/*
> --
> 2.25.1
>