*
* LR = return address to continue at after eventually re-enabling MMU
*/
- _GLOBAL(kvmppc_hv_entry_trampoline)
+ _GLOBAL_TOC(kvmppc_hv_entry_trampoline)
mflr r0
std r0, PPC_LR_STKOFF(r1)
stdu r1, -112(r1)
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.