On 5/6/2025 6:37 PM, Tianyu Lan wrote:
> From: Tianyu Lan <ti...@microsoft.com>
>
> When Secure AVIC is not enabled, init_apic_page()
> should return directly.
>
> Signed-off-by: Tianyu Lan <ti...@microsoft.com>
> ---
> arch/x86/kernel/apic/x2apic_savic.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kernel/apic/x2apic_savic.c
> b/arch/x86/kernel/apic/x2apic_savic.c
> index 0dd7e39931b0..fb09c0f9e276 100644
> --- a/arch/x86/kernel/apic/x2apic_savic.c
> +++ b/arch/x86/kernel/apic/x2apic_savic.c
> @@ -333,6 +333,9 @@ static void init_apic_page(void)
> {
> u32 apic_id;
>
> + if (!cc_platform_has(CC_ATTR_SNP_SECURE_AVIC))
> + return;
> +
> /*
Why is this change needed? init_apic_page() is only called from Secure AVIC
driver's
setup() callback. savic_probe() already does this check. So, if this check
fails during
savic_probe(), Secure AVIC apic driver won't be selected as apic driver and
it's setup
callback will never get invoked.
- Neeraj
> * Before Secure AVIC is enabled, APIC msr reads are intercepted.
> * APIC_ID msr read returns the value from the Hypervisor.
