[PATCH 7/7] x86/hyperv: Use the ACPI wakeup mailbox for VTL2 guests when available

[Yunhong Jiang <yunhong.jiang@linux.intel.com>]

The VTL2 in a TDX guest can boot utilizing the device tree instead of
ACPI tables. When the ACPI wakeup mailbox is present in device tree,
don't overwrite wakeup_secondary_cpu_64 so that the acpi_wakeup_cpu will
be used to bring up the APs.

Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
---
 arch/x86/hyperv/hv_vtl.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index a1eb5548bd4d..132d05fd9136 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -276,9 +276,10 @@ int __init hv_vtl_early_init(void)
 		panic("XSAVE has to be disabled as it is not supported by this module.\n"
 			  "Please add 'noxsave' to the kernel command line.\n");
 
-	if (!wakeup_mailbox_addr)
+	if (!wakeup_mailbox_addr) {
 		real_mode_header = &hv_vtl_real_mode_header;
-	apic_update_callback(wakeup_secondary_cpu_64, hv_vtl_wakeup_secondary_cpu);
+		apic_update_callback(wakeup_secondary_cpu_64, hv_vtl_wakeup_secondary_cpu);
+	}
 
 	return 0;
 }
-- 
2.25.1