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-rw-r--r--arch/powerpc/kvm/book3s_hv_ras.c15
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S19
2 files changed, 23 insertions, 11 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index 768a9f977c00..3a5c568b1e89 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -113,10 +113,8 @@ static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
* We assume that if the condition is recovered then linux host
* will have generated an error log event that we will pick
* up and log later.
- * Don't release mce event now. In case if condition is not
- * recovered we do guest exit and go back to linux host machine
- * check handler. Hence we need make sure that current mce event
- * is available for linux host to consume.
+ * Don't release mce event now. We will queue up the event so that
+ * we can log the MCE event info on host console.
*/
if (!get_mce_event(&mce_evt, MCE_EVENT_DONTRELEASE))
goto out;
@@ -128,11 +126,12 @@ static long kvmppc_realmode_mc_power7(struct kvm_vcpu *vcpu)
out:
/*
- * If we have handled the error, then release the mce event because
- * we will be delivering machine check to guest.
+ * We are now going enter guest either through machine check
+ * interrupt (for unhandled errors) or will continue from
+ * current HSRR0 (for handled errors) in guest. Hence
+ * queue up the event so that we can log it from host console later.
*/
- if (handled)
- release_mce_event();
+ machine_check_queue_event();
return handled;
}
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 77356fd25ccc..868347ef09fd 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2257,15 +2257,28 @@ machine_check_realmode:
mr r3, r9 /* get vcpu pointer */
bl kvmppc_realmode_machine_check
nop
- cmpdi r3, 0 /* continue exiting from guest? */
+ cmpdi r3, 0 /* Did we handle MCE ? */
ld r9, HSTATE_KVM_VCPU(r13)
li r12, BOOK3S_INTERRUPT_MACHINE_CHECK
- beq mc_cont
+ /*
+ * Deliver unhandled/fatal (e.g. UE) MCE errors to guest through
+ * machine check interrupt (set HSRR0 to 0x200). And for handled
+ * errors (no-fatal), just go back to guest execution with current
+ * HSRR0 instead of exiting guest. This new approach will inject
+ * machine check to guest for fatal error causing guest to crash.
+ *
+ * The old code used to return to host for unhandled errors which
+ * was causing guest to hang with soft lockups inside guest and
+ * makes it difficult to recover guest instance.
+ */
+ ld r10, VCPU_PC(r9)
+ ld r11, VCPU_MSR(r9)
+ bne 2f /* Continue guest execution. */
/* If not, deliver a machine check. SRR0/1 are already set */
li r10, BOOK3S_INTERRUPT_MACHINE_CHECK
ld r11, VCPU_MSR(r9)
bl kvmppc_msr_interrupt
- b fast_interrupt_c_return
+2: b fast_interrupt_c_return
/*
* Check the reason we woke from nap, and take appropriate action.