[RFC PATCH 2/6] x86/x2apic-savic: Expose x2apic_savic_update_vector()

[Tianyu Lan <ltykernel@gmail.com>]

From: Tianyu Lan <tiala@microsoft.com>

Expose x2apic_savic_update_vector() and device driver
arch code may update AVIC backing page to allow Hyper-V
inject associated vector.

Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
 arch/x86/include/asm/apic.h         | 9 +++++++++
 arch/x86/kernel/apic/x2apic_savic.c | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 6aa4b8ff08a9..949389e05dd7 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -241,6 +241,15 @@ static inline u64 native_x2apic_icr_read(void)
 	return val;
 }
 
+#if defined(CONFIG_AMD_SECURE_AVIC)
+extern void x2apic_savic_update_vector(unsigned int cpu,
+				unsigned int vector,
+				bool set);
+#else
+static inline void x2apic_savic_update_vector(unsigned int cpu,
+					      unsigned int vector,								      bool set) { }
+#endif
+
 extern int x2apic_mode;
 extern int x2apic_phys;
 extern void __init x2apic_set_max_apicid(u32 apicid);
diff --git a/arch/x86/kernel/apic/x2apic_savic.c b/arch/x86/kernel/apic/x2apic_savic.c
index 6284d1f8dac9..0dd7e39931b0 100644
--- a/arch/x86/kernel/apic/x2apic_savic.c
+++ b/arch/x86/kernel/apic/x2apic_savic.c
@@ -321,6 +321,14 @@ static void savic_update_vector(unsigned int cpu, unsigned int vector, bool set)
 	update_vector(cpu, SAVIC_ALLOWED_IRR, vector, set);
 }
 
+void x2apic_savic_update_vector(unsigned int cpu, unsigned int vector, bool set)
+{
+	if (!cc_platform_has(CC_ATTR_SNP_SECURE_AVIC))
+		return;
+
+	savic_update_vector(cpu, vector, set);
+}
+
 static void init_apic_page(void)
 {
 	u32 apic_id;
-- 
2.25.1