Subject: [PATCH 2/2] powerpc/64s: Better printing of machine check info for guest MCEs

From: Paul Mackerras <[email-masked]>
Date: Wed, 20 Feb 2019 12:06:23 +1100

This adds an "in_guest" parameter to machine_check_print_event_info()
so that we can avoid trying to translate guest NIP values into
symbolic form using the host kernel's symbol table.

Signed-off-by: Paul Mackerras <[email-masked]>
---
 arch/powerpc/include/asm/mce.h        | 2 +-
 arch/powerpc/kernel/mce.c             | 8 +++++---
 arch/powerpc/kvm/book3s_hv.c          | 4 ++--
 arch/powerpc/platforms/powernv/opal.c | 2 +-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index a8b8903..17996bc 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -209,7 +209,7 @@ extern int get_mce_event(struct machine_check_event *mce, bool release);
 extern void release_mce_event(void);
 extern void machine_check_queue_event(void);
 extern void machine_check_print_event_info(struct machine_check_event *evt,
-					   bool user_mode);
+					   bool user_mode, bool in_guest);
 #ifdef CONFIG_PPC_BOOK3S_64
 void flush_and_reload_slb(void);
 #endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index bd933a7..d01b690 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -301,13 +301,13 @@ static void machine_check_process_queued_event(struct irq_work *work)
 	while (__this_cpu_read(mce_queue_count) > 0) {
 		index = __this_cpu_read(mce_queue_count) - 1;
 		evt = this_cpu_ptr(&mce_event_queue[index]);
-		machine_check_print_event_info(evt, false);
+		machine_check_print_event_info(evt, false, false);
 		__this_cpu_dec(mce_queue_count);
 	}
 }
 
 void machine_check_print_event_info(struct machine_check_event *evt,
-				    bool user_mode)
+				    bool user_mode, bool in_guest)
 {
 	const char *level, *sevstr, *subtype;
 	static const char *mc_ue_types[] = {
@@ -387,7 +387,9 @@ void machine_check_print_event_info(struct machine_check_event *evt,
 	       evt->disposition == MCE_DISPOSITION_RECOVERED ?
 	       "Recovered" : "Not recovered");
 
-	if (user_mode) {
+	if (in_guest) {
+		printk("%s  Guest NIP: %016llx\n", evt->srr0);
+	} else if (user_mode) {
 		printk("%s  NIP: [%016llx] PID: %d Comm: %s\n", level,
 			evt->srr0, current->pid, current->comm);
 	} else {
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d8bf05a..81cba4b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1216,7 +1216,7 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		break;
 	case BOOK3S_INTERRUPT_MACHINE_CHECK:
 		/* Print the MCE event to host console. */
-		machine_check_print_event_info(&vcpu->arch.mce_evt, false);
+		machine_check_print_event_info(&vcpu->arch.mce_evt, false, true);
 
 		/*
 		 * If the guest can do FWNMI, exit to userspace so it can
@@ -1406,7 +1406,7 @@ static int kvmppc_handle_nested_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		/* Pass the machine check to the L1 guest */
 		r = RESUME_HOST;
 		/* Print the MCE event to host console. */
-		machine_check_print_event_info(&vcpu->arch.mce_evt, false);
+		machine_check_print_event_info(&vcpu->arch.mce_evt, false, true);
 		break;
 	/*
 	 * We get these next two if the guest accesses a page which it thinks
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 79586f1..05c85be 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -587,7 +587,7 @@ int opal_machine_check(struct pt_regs *regs)
 		       evt.version);
 		return 0;
 	}
-	machine_check_print_event_info(&evt, user_mode(regs));
+	machine_check_print_event_info(&evt, user_mode(regs), false);
 
 	if (opal_recover_mce(regs, &evt))
 		return 1;
-- 
2.7.4