From: Tianyu Lan <ltyker...@gmail.com> Sent: Tuesday, May 6, 2025 6:07 AM
>
Suggested Subject line:
x86/hyperv: Don't use hv 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().
Suggested wording:
When Secure AVIC is available, the AMD x2apic Secure AVIC
driver will be selected. So skip initialization of the
Hyper-V apic driver.
>
> Signed-off-by: Tianyu Lan <ti...@microsoft.com>
> ---
> 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 6d91ac5f9836..bd8f83923305 100644
> --- a/arch/x86/hyperv/hv_apic.c
> +++ b/arch/x86/hyperv/hv_apic.c
> @@ -292,6 +292,9 @@ 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");
> /*
It seems like this patch will cause a bisect problem if a bisect includes
this patch but none of the subsequent patches in this series. The
Hyper-V guest VM could see Secure AVIC is enabled, but the VM
wouldn't boot because the code to allow Hyper-V to inject an interrupt
haven't been added yet.
This patch probably should come later in the patch series after Secure
AVIC can be functional in a Hyper-V guest.
Michael
