Re: [RFC v5 065/126] XIVE: introduce ERRP_AUTO_PROPAGATE

[Greg Kurz <groug@kaod.org>]

On Fri, 11 Oct 2019 19:04:51 +0300
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> wrote:

> If we want to add some info to errp (by error_prepend() or
> error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
> Otherwise, this info will not be added when errp == &fatal_err
> (the program will exit prior to the error_append_hint() or
> error_prepend() call).  Fix such cases.
> 
> If we want to check error after errp-function call, we need to
> introduce local_err and than propagate it to errp. Instead, use
> ERRP_AUTO_PROPAGATE macro, benefits are:
> 1. No need of explicit error_propagate call
> 2. No need of explicit local_err variable: use errp directly
> 3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
>    &error_fatel, this means that we don't break error_abort
>    (we'll abort on error_set, not on error_propagate)
> 
> This commit (together with its neighbors) was generated by
> 
> for f in $(git grep -l errp \*.[ch]); do \
>     spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
>     --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff $f; \
> done;
> 
> then fix a bit of compilation problems: coccinelle for some reason
> leaves several
> f() {
>     ...
>     goto out;
>     ...
>     out:
> }
> patterns, with "out:" at function end.
> 
> then
> ./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"
> 
> (auto-msg was a file with this commit message)
> 
> Still, for backporting it may be more comfortable to use only the first
> command and then do one huge commit.
> 
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> Reported-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  hw/intc/spapr_xive.c     | 12 ++++-----
>  hw/intc/spapr_xive_kvm.c | 55 ++++++++++++++++++----------------------
>  hw/intc/xive.c           | 27 ++++++++------------
>  3 files changed, 40 insertions(+), 54 deletions(-)
> 

We did a huge cleanup recently in this area so this patch doesn't apply
anymore. Ideally it should be based on David Gibson's ppc-for-5.0 branch
available at https://github.com/dgibson/qemu .

Same goes for the PowerPC patch 035/126 actually.

> diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
> index 04879abf2e..b25c9ef9ea 100644
> --- a/hw/intc/spapr_xive.c
> +++ b/hw/intc/spapr_xive.c
> @@ -273,10 +273,10 @@ static void spapr_xive_instance_init(Object *obj)
>  
>  static void spapr_xive_realize(DeviceState *dev, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      SpaprXive *xive = SPAPR_XIVE(dev);
>      XiveSource *xsrc = &xive->source;
>      XiveENDSource *end_xsrc = &xive->end_source;
> -    Error *local_err = NULL;
>  
>      if (!xive->nr_irqs) {
>          error_setg(errp, "Number of interrupt needs to be greater 0");
> @@ -295,9 +295,8 @@ static void spapr_xive_realize(DeviceState *dev, Error **errp)
>                              &error_fatal);
>      object_property_add_const_link(OBJECT(xsrc), "xive", OBJECT(xive),
>                                     &error_fatal);
> -    object_property_set_bool(OBJECT(xsrc), true, "realized", &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    object_property_set_bool(OBJECT(xsrc), true, "realized", errp);
> +    if (*errp) {
>          return;
>      }
>      sysbus_init_mmio(SYS_BUS_DEVICE(xive), &xsrc->esb_mmio);
> @@ -309,9 +308,8 @@ static void spapr_xive_realize(DeviceState *dev, Error **errp)
>                              &error_fatal);
>      object_property_add_const_link(OBJECT(end_xsrc), "xive", OBJECT(xive),
>                                     &error_fatal);
> -    object_property_set_bool(OBJECT(end_xsrc), true, "realized", &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    object_property_set_bool(OBJECT(end_xsrc), true, "realized", errp);
> +    if (*errp) {
>          return;
>      }
>      sysbus_init_mmio(SYS_BUS_DEVICE(xive), &end_xsrc->esb_mmio);
> diff --git a/hw/intc/spapr_xive_kvm.c b/hw/intc/spapr_xive_kvm.c
> index 51b334b676..02243537e6 100644
> --- a/hw/intc/spapr_xive_kvm.c
> +++ b/hw/intc/spapr_xive_kvm.c
> @@ -186,6 +186,7 @@ void kvmppc_xive_cpu_connect(XiveTCTX *tctx, Error **errp)
>  void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
>                                     Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      uint32_t end_idx;
>      uint32_t end_blk;
>      uint8_t priority;
> @@ -193,7 +194,6 @@ void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
>      bool masked;
>      uint32_t eisn;
>      uint64_t kvm_src;
> -    Error *local_err = NULL;
>  
>      assert(xive_eas_is_valid(eas));
>  
> @@ -214,9 +214,8 @@ void kvmppc_xive_set_source_config(SpaprXive *xive, uint32_t lisn, XiveEAS *eas,
>          KVM_XIVE_SOURCE_EISN_MASK;
>  
>      kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_SOURCE_CONFIG, lisn,
> -                      &kvm_src, true, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +                      &kvm_src, true, errp);
> +    if (*errp) {
>          return;
>      }
>  }
> @@ -255,19 +254,17 @@ int kvmppc_xive_source_reset_one(XiveSource *xsrc, int srcno, Error **errp)
>  
>  static void kvmppc_xive_source_reset(XiveSource *xsrc, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      SpaprXive *xive = SPAPR_XIVE(xsrc->xive);
>      int i;
>  
>      for (i = 0; i < xsrc->nr_irqs; i++) {
> -        Error *local_err = NULL;
> -
>          if (!xive_eas_is_valid(&xive->eat[i])) {
>              continue;
>          }
>  
> -        kvmppc_xive_source_reset_one(xsrc, i, &local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +        kvmppc_xive_source_reset_one(xsrc, i, errp);
> +        if (*errp) {
>              return;
>          }
>      }
> @@ -389,11 +386,11 @@ void kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
>                                    uint32_t end_idx, XiveEND *end,
>                                    Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      struct kvm_ppc_xive_eq kvm_eq = { 0 };
>      uint64_t kvm_eq_idx;
>      uint8_t priority;
>      uint32_t server;
> -    Error *local_err = NULL;
>  
>      assert(xive_end_is_valid(end));
>  
> @@ -406,9 +403,8 @@ void kvmppc_xive_get_queue_config(SpaprXive *xive, uint8_t end_blk,
>          KVM_XIVE_EQ_SERVER_MASK;
>  
>      kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
> -                      &kvm_eq, false, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +                      &kvm_eq, false, errp);
> +    if (*errp) {
>          return;
>      }
>  
> @@ -425,11 +421,11 @@ void kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
>                                    uint32_t end_idx, XiveEND *end,
>                                    Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      struct kvm_ppc_xive_eq kvm_eq = { 0 };
>      uint64_t kvm_eq_idx;
>      uint8_t priority;
>      uint32_t server;
> -    Error *local_err = NULL;
>  
>      /*
>       * Build the KVM state from the local END structure.
> @@ -468,9 +464,8 @@ void kvmppc_xive_set_queue_config(SpaprXive *xive, uint8_t end_blk,
>          KVM_XIVE_EQ_SERVER_MASK;
>  
>      kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_EQ_CONFIG, kvm_eq_idx,
> -                      &kvm_eq, true, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +                      &kvm_eq, true, errp);
> +    if (*errp) {
>          return;
>      }
>  }
> @@ -483,7 +478,7 @@ void kvmppc_xive_reset(SpaprXive *xive, Error **errp)
>  
>  static void kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
>  {
> -    Error *local_err = NULL;
> +    ERRP_AUTO_PROPAGATE();
>      int i;
>  
>      for (i = 0; i < xive->nr_ends; i++) {
> @@ -492,9 +487,8 @@ static void kvmppc_xive_get_queues(SpaprXive *xive, Error **errp)
>          }
>  
>          kvmppc_xive_get_queue_config(xive, SPAPR_XIVE_BLOCK_ID, i,
> -                                     &xive->endt[i], &local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +                                     &xive->endt[i], errp);
> +        if (*errp) {
>              return;
>          }
>      }
> @@ -742,8 +736,8 @@ static void *kvmppc_xive_mmap(SpaprXive *xive, int pgoff, size_t len,
>   */
>  void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      XiveSource *xsrc = &xive->source;
> -    Error *local_err = NULL;
>      size_t esb_len = (1ull << xsrc->esb_shift) * xsrc->nr_irqs;
>      size_t tima_len = 4ull << TM_SHIFT;
>      CPUState *cs;
> @@ -772,8 +766,8 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
>       * 1. Source ESB pages - KVM mapping
>       */
>      xsrc->esb_mmap = kvmppc_xive_mmap(xive, KVM_XIVE_ESB_PAGE_OFFSET, esb_len,
> -                                      &local_err);
> -    if (local_err) {
> +                                      errp);
> +    if (*errp) {
>          goto fail;
>      }
>  
> @@ -790,8 +784,8 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
>       * 3. TIMA pages - KVM mapping
>       */
>      xive->tm_mmap = kvmppc_xive_mmap(xive, KVM_XIVE_TIMA_PAGE_OFFSET, tima_len,
> -                                     &local_err);
> -    if (local_err) {
> +                                     errp);
> +    if (*errp) {
>          goto fail;
>      }
>      memory_region_init_ram_device_ptr(&xive->tm_mmio_kvm, OBJECT(xive),
> @@ -806,15 +800,15 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
>      CPU_FOREACH(cs) {
>          PowerPCCPU *cpu = POWERPC_CPU(cs);
>  
> -        kvmppc_xive_cpu_connect(spapr_cpu_state(cpu)->tctx, &local_err);
> -        if (local_err) {
> +        kvmppc_xive_cpu_connect(spapr_cpu_state(cpu)->tctx, errp);
> +        if (*errp) {
>              goto fail;
>          }
>      }
>  
>      /* Update the KVM sources */
> -    kvmppc_xive_source_reset(xsrc, &local_err);
> -    if (local_err) {
> +    kvmppc_xive_source_reset(xsrc, errp);
> +    if (*errp) {
>          goto fail;
>      }
>  
> @@ -824,7 +818,6 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp)
>      return;
>  
>  fail:
> -    error_propagate(errp, local_err);
>      kvmppc_xive_disconnect(xive, NULL);
>  }
>  
> diff --git a/hw/intc/xive.c b/hw/intc/xive.c
> index 29df06df11..368f94df71 100644
> --- a/hw/intc/xive.c
> +++ b/hw/intc/xive.c
> @@ -570,15 +570,14 @@ static void xive_tctx_reset(void *dev)
>  
>  static void xive_tctx_realize(DeviceState *dev, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      XiveTCTX *tctx = XIVE_TCTX(dev);
>      PowerPCCPU *cpu;
>      CPUPPCState *env;
>      Object *obj;
> -    Error *local_err = NULL;
>  
> -    obj = object_property_get_link(OBJECT(dev), "cpu", &local_err);
> +    obj = object_property_get_link(OBJECT(dev), "cpu", errp);
>      if (!obj) {
> -        error_propagate(errp, local_err);
>          error_prepend(errp, "required link 'cpu' not found: ");
>          return;
>      }
> @@ -601,9 +600,8 @@ static void xive_tctx_realize(DeviceState *dev, Error **errp)
>  
>      /* Connect the presenter to the VCPU (required for CPU hotplug) */
>      if (kvm_irqchip_in_kernel()) {
> -        kvmppc_xive_cpu_connect(tctx, &local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> +        kvmppc_xive_cpu_connect(tctx, errp);
> +        if (*errp) {
>              return;
>          }
>      }
> @@ -681,15 +679,15 @@ static const TypeInfo xive_tctx_info = {
>  
>  Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, Error **errp)
>  {
> -    Error *local_err = NULL;
> +    ERRP_AUTO_PROPAGATE();
>      Object *obj;
>  
>      obj = object_new(TYPE_XIVE_TCTX);
>      object_property_add_child(cpu, TYPE_XIVE_TCTX, obj, &error_abort);
>      object_unref(obj);
>      object_property_add_const_link(obj, "cpu", cpu, &error_abort);
> -    object_property_set_bool(obj, true, "realized", &local_err);
> -    if (local_err) {
> +    object_property_set_bool(obj, true, "realized", errp);
> +    if (*errp) {
>          goto error;
>      }
>  
> @@ -697,7 +695,6 @@ Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, Error **errp)
>  
>  error:
>      object_unparent(obj);
> -    error_propagate(errp, local_err);
>      return NULL;
>  }
>  
> @@ -1050,13 +1047,12 @@ static void xive_source_reset(void *dev)
>  
>  static void xive_source_realize(DeviceState *dev, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      XiveSource *xsrc = XIVE_SOURCE(dev);
>      Object *obj;
> -    Error *local_err = NULL;
>  
> -    obj = object_property_get_link(OBJECT(dev), "xive", &local_err);
> +    obj = object_property_get_link(OBJECT(dev), "xive", errp);
>      if (!obj) {
> -        error_propagate(errp, local_err);
>          error_prepend(errp, "required link 'xive' not found: ");
>          return;
>      }
> @@ -1806,13 +1802,12 @@ static const MemoryRegionOps xive_end_source_ops = {
>  
>  static void xive_end_source_realize(DeviceState *dev, Error **errp)
>  {
> +    ERRP_AUTO_PROPAGATE();
>      XiveENDSource *xsrc = XIVE_END_SOURCE(dev);
>      Object *obj;
> -    Error *local_err = NULL;
>  
> -    obj = object_property_get_link(OBJECT(dev), "xive", &local_err);
> +    obj = object_property_get_link(OBJECT(dev), "xive", errp);
>      if (!obj) {
> -        error_propagate(errp, local_err);
>          error_prepend(errp, "required link 'xive' not found: ");
>          return;
>      }