From 4f7a11f93fcb970bdcd2faa12337f4d1269b45f4 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Thu, 26 Mar 2020 00:29:06 +1000 Subject: [PATCH] ppc/spapr: Don't kill the guest if a recovered FWNMI machine check delivery fails Try to be tolerant of FWNMI delivery errors if the machine check had been recovered by the host. Signed-off-by: Nicholas Piggin Message-Id: <20200325142906.221248-5-npiggin@gmail.com> Reviewed-by: Greg Kurz [dwg: Updated comment at Greg's suggestion] Signed-off-by: David Gibson --- hw/ppc/spapr_events.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c index c8964eb25d..1069d0197b 100644 --- a/hw/ppc/spapr_events.c +++ b/hw/ppc/spapr_events.c @@ -833,13 +833,28 @@ static void spapr_mce_dispatch_elog(PowerPCCPU *cpu, bool recovered) /* get rtas addr from fdt */ rtas_addr = spapr_get_rtas_addr(); if (!rtas_addr) { - error_report( + if (!recovered) { + error_report( "FWNMI: Unable to deliver machine check to guest: rtas_addr not found."); - qemu_system_guest_panicked(NULL); + qemu_system_guest_panicked(NULL); + } else { + warn_report( +"FWNMI: Unable to deliver machine check to guest: rtas_addr not found. " +"Machine check recovered."); + } g_free(ext_elog); return; } + /* + * By taking the interlock, we assume that the MCE will be + * delivered to the guest. CAUTION: don't add anything that could + * prevent the MCE to be delivered after this line, otherwise the + * guest won't be able to release the interlock and ultimately + * hang/crash? + */ + spapr->fwnmi_machine_check_interlock = cpu->vcpu_id; + stq_be_phys(&address_space_memory, rtas_addr + RTAS_ERROR_LOG_OFFSET, env->gpr[3]); cpu_physical_memory_write(rtas_addr + RTAS_ERROR_LOG_OFFSET + @@ -876,9 +891,15 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered) * that CPU called "ibm,nmi-interlock") */ if (spapr->fwnmi_machine_check_interlock == cpu->vcpu_id) { - error_report( + if (!recovered) { + error_report( "FWNMI: Unable to deliver machine check to guest: nested machine check."); - qemu_system_guest_panicked(NULL); + qemu_system_guest_panicked(NULL); + } else { + warn_report( +"FWNMI: Unable to deliver machine check to guest: nested machine check. " +"Machine check recovered."); + } return; } qemu_cond_wait_iothread(&spapr->fwnmi_machine_check_interlock_cond); @@ -906,7 +927,6 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered) warn_report("Received a fwnmi while migration was in progress"); } - spapr->fwnmi_machine_check_interlock = cpu->vcpu_id; spapr_mce_dispatch_elog(cpu, recovered); } -- 2.30.2