[RFC PATCH V6 1/4] x86/hyperv: Don't use hv apic driver when Secure AVIC is available

[Tianyu Lan <ltykernel@gmail.com>]

From: Tianyu Lan <tiala@microsoft.com>

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.

Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
Change since RFC V3:
       - Update Change log and fix coding style issue.
---
 arch/x86/hyperv/hv_apic.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index bfde0a3498b9..01bc02cc0590 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -25,6 +25,7 @@
 #include <linux/clockchips.h>
 #include <linux/slab.h>
 #include <linux/cpuhotplug.h>
+#include <linux/cc_platform.h>
 #include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
 #include <asm/apic.h>
@@ -293,6 +294,9 @@ 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