On Tue, 4 Jun 2019 12:34:37 +0530
Aravinda Prasad <aravi...@linux.vnet.ibm.com> wrote:
> On Monday 03 June 2019 09:10 PM, Greg Kurz wrote:
> > On Wed, 29 May 2019 11:10:57 +0530
> > Aravinda Prasad <aravi...@linux.vnet.ibm.com> wrote:
> >
> >> This patch includes migration support for machine check
> >> handling. Especially this patch blocks VM migration
> >> requests until the machine check error handling is
> >> complete as (i) these errors are specific to the source
> >> hardware and is irrelevant on the target hardware,
> >> (ii) these errors cause data corruption and should
> >> be handled before migration.
> >>
> >> Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com>
> >> ---
> >
> > LGTM, just one issue: machine reset should del and free the blocker as well,
> > otherwise QEMU would crash if spapr_mce_req_event() is called again.
>
> Sure.
>
>
> >
> >> hw/ppc/spapr.c | 20 ++++++++++++++++++++
> >> hw/ppc/spapr_events.c | 17 +++++++++++++++++
> >> hw/ppc/spapr_rtas.c | 4 ++++
> >> include/hw/ppc/spapr.h | 2 ++
> >> 4 files changed, 43 insertions(+)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index e8a77636..31c4850 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -2104,6 +2104,25 @@ static const VMStateDescription vmstate_spapr_dtb =
> >> {
> >> },
> >> };
> >>
> >> +static bool spapr_fwnmi_needed(void *opaque)
> >> +{
> >> + SpaprMachineState *spapr = (SpaprMachineState *)opaque;
> >> +
> >> + return (spapr->guest_machine_check_addr == -1) ? 0 : 1;
And also you can drop the parens since == as precedence over ?:
> >> +}
> >> +
> >> +static const VMStateDescription vmstate_spapr_machine_check = {
> >> + .name = "spapr_machine_check",
> >> + .version_id = 1,
> >> + .minimum_version_id = 1,
> >> + .needed = spapr_fwnmi_needed,
> >> + .fields = (VMStateField[]) {
> >> + VMSTATE_UINT64(guest_machine_check_addr, SpaprMachineState),
> >> + VMSTATE_INT32(mc_status, SpaprMachineState),
> >> + VMSTATE_END_OF_LIST()
> >> + },
> >> +};
> >> +
> >> static const VMStateDescription vmstate_spapr = {
> >> .name = "spapr",
> >> .version_id = 3,
> >> @@ -2137,6 +2156,7 @@ static const VMStateDescription vmstate_spapr = {
> >> &vmstate_spapr_dtb,
> >> &vmstate_spapr_cap_large_decr,
> >> &vmstate_spapr_cap_ccf_assist,
> >> + &vmstate_spapr_machine_check,
> >> NULL
> >> }
> >> };
> >> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> >> index 573c0b7..35e21e4 100644
> >> --- a/hw/ppc/spapr_events.c
> >> +++ b/hw/ppc/spapr_events.c
> >> @@ -41,6 +41,7 @@
> >> #include "qemu/bcd.h"
> >> #include "hw/ppc/spapr_ovec.h"
> >> #include <libfdt.h>
> >> +#include "migration/blocker.h"
> >>
> >> #define RTAS_LOG_VERSION_MASK 0xff000000
> >> #define RTAS_LOG_VERSION_6 0x06000000
> >> @@ -855,6 +856,22 @@ static void spapr_mce_dispatch_elog(PowerPCCPU *cpu,
> >> bool recovered)
> >> void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
> >> {
> >> SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> >> + int ret;
> >> + Error *local_err = NULL;
> >> +
> >> + error_setg(&spapr->fwnmi_migration_blocker,
> >> + "Live migration not supported during machine check handling");
> >> + ret = migrate_add_blocker(spapr->fwnmi_migration_blocker, &local_err);
> >> + if (ret < 0) {
> >> + /*
> >> + * We don't want to abort and let the migration to continue. In a
> >> + * rare case, the machine check handler will run on the target
> >> + * hardware. Though this is not preferable, it is better than
> >> aborting
> >> + * the migration or killing the VM.
> >> + */
> >> + error_free(spapr->fwnmi_migration_blocker);
> >> + warn_report_err(local_err);
> >> + }
> >>
> >> while (spapr->mc_status != -1) {
> >> /*
> >> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >> index 91a7ab9..c849223 100644
> >> --- a/hw/ppc/spapr_rtas.c
> >> +++ b/hw/ppc/spapr_rtas.c
> >> @@ -50,6 +50,7 @@
> >> #include "target/ppc/mmu-hash64.h"
> >> #include "target/ppc/mmu-book3s-v3.h"
> >> #include "kvm_ppc.h"
> >> +#include "migration/blocker.h"
> >>
> >> static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState
> >> *spapr,
> >> uint32_t token, uint32_t nargs,
> >> @@ -404,6 +405,9 @@ static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
> >> spapr->mc_status = -1;
> >> qemu_cond_signal(&spapr->mc_delivery_cond);
> >> rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> >> + migrate_del_blocker(spapr->fwnmi_migration_blocker);
> >> + error_free(spapr->fwnmi_migration_blocker);
> >> + spapr->fwnmi_migration_blocker = NULL;
> >> }
> >> }
> >>
> >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> >> index bd75d4b..6c0cfd8 100644
> >> --- a/include/hw/ppc/spapr.h
> >> +++ b/include/hw/ppc/spapr.h
> >> @@ -214,6 +214,8 @@ struct SpaprMachineState {
> >> SpaprCapabilities def, eff, mig;
> >>
> >> unsigned gpu_numa_id;
> >> +
> >> + Error *fwnmi_migration_blocker;
> >> };
> >>
> >> #define H_SUCCESS 0
> >>
> >>
> >
>
