hyperv: Introduce hv_recommend_using_aeoi()

Factor out the check for enabling auto eoi, to be reused in root
partition code.

No functional changes.

Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/r/1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1741980536-3865-5-git-send-email-nunodasneves@linux.microsoft.com>

Author: NunoDasNeves

drivers/hv/hv.c

@@ -313,17 +313,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 
 	shared_sint.vector = vmbus_interrupt;
 	shared_sint.masked = false;
-
-	/*
-	 * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
-	 * it doesn't provide a recommendation flag and AEOI must be disabled.
-	 */
-#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
-	shared_sint.auto_eoi =
-			!(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
-#else
-	shared_sint.auto_eoi = 0;
-#endif
+	shared_sint.auto_eoi = hv_recommend_using_aeoi();
 	hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 
 	/* Enable the global synic bit */

include/asm-generic/mshyperv.h

@@ -77,6 +77,19 @@ u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2);
 bool hv_isolation_type_snp(void);
 bool hv_isolation_type_tdx(void);
 
+/*
+ * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
+ * it doesn't provide a recommendation flag and AEOI must be disabled.
+ */
+static inline bool hv_recommend_using_aeoi(void)
+{
+#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
+	return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
+#else
+	return false;
+#endif
+}
+
 static inline struct hv_proximity_domain_info hv_numa_node_to_pxm_info(int node)
 {
 	struct hv_proximity_domain_info pxm_info = {};