[PATCH v3 1/3] x86/boot: print CPU and APIC ID in bring up failure

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Print the CPU and APIC ID that fails to respond to the init sequence, or
that didn't manage to reach the "callin" state.  Expand a bit the printed
error messages.  Otherwise the "Not responding." message is not easy to
understand by users.

Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Changes since v2:
 - Adjust format string.

Changes since v1:
 - Also print APIC ID.
---
 xen/arch/x86/smpboot.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 0189d6c332a4..b5dcc77bd574 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -618,10 +618,12 @@ static int do_boot_cpu(int apicid, int cpu)
             smp_mb();
             if ( bootsym(trampoline_cpu_started) == 0xA5 )
                 /* trampoline started but...? */
-                printk("Stuck ??\n");
+                printk("APIC ID %#x (CPU%u) didn't finish start sequence\n",
+                       apicid, cpu);
             else
                 /* trampoline code not run */
-                printk("Not responding.\n");
+                printk("APIC ID %#x (CPU%u) didn't respond to SIPI\n",
+                       apicid, cpu);
         }
     }
 
-- 
2.49.0