[PATCH v9 18/27] migration: push Error **errp into loadvm_postcopy_ram_handle_discard()

Arun Menon posted 27 patches 4 months, 1 week ago
Maintainers: Stefan Berger <stefanb@linux.vnet.ibm.com>, Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>, "Michael S. Tsirkin" <mst@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>, Dmitry Osipenko <dmitry.osipenko@collabora.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Cornelia Huck <cohuck@redhat.com>, Halil Pasic <pasic@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Matthew Rosato <mjrosato@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Nicholas Piggin <npiggin@gmail.com>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Paolo Bonzini <pbonzini@redhat.com>, Fam Zheng <fam@euphon.net>, Alex Williamson <alex.williamson@redhat.com>, "Cédric Le Goater" <clg@redhat.com>, Hailiang Zhang <zhanghailiang@xfusion.com>, Steve Sistare <steven.sistare@oracle.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>
There is a newer version of this series
[PATCH v9 18/27] migration: push Error **errp into loadvm_postcopy_ram_handle_discard()
Posted by Arun Menon 4 months, 1 week ago
This is an incremental step in converting vmstate loading
code to report error via Error objects instead of directly
printing it to console/monitor.
It is ensured that loadvm_postcopy_ram_handle_discard() must report an error
in errp, in case of failure.

Signed-off-by: Arun Menon <armenon@redhat.com>
---
 migration/savevm.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index eb90873a750ded354b3db31cba40b44d1be79864..3abe4193e02aae9c813ff07fb388a7ee470c8a6a 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2004,7 +2004,7 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
  * There can be 0..many of these messages, each encoding multiple pages.
  */
 static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
-                                              uint16_t len)
+                                              uint16_t len, Error **errp)
 {
     int tmp;
     char ramid[256];
@@ -2017,6 +2017,7 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         /* 1st discard */
         tmp = postcopy_ram_prepare_discard(mis);
         if (tmp) {
+            error_setg(errp, "Failed to prepare for RAM discard: %d", tmp);
             return tmp;
         }
         break;
@@ -2026,8 +2027,9 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         break;
 
     default:
-        error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
-                     ps);
+        error_setg(errp,
+                   "CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
+                   ps);
         return -1;
     }
     /* We're expecting a
@@ -2036,29 +2038,30 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
      *    then at least 1 16 byte chunk
     */
     if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
         return -1;
     }
 
     tmp = qemu_get_byte(mis->from_src_file);
     if (tmp != postcopy_ram_discard_version) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
         return -1;
     }
 
     if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
+        error_setg(errp,
+                   "CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
         return -1;
     }
     tmp = qemu_get_byte(mis->from_src_file);
     if (tmp != 0) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
         return -1;
     }
 
     len -= 3 + strlen(ramid);
     if (len % 16) {
-        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
         return -1;
     }
     trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
@@ -2070,6 +2073,7 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
         len -= 16;
         int ret = ram_discard_range(ramid, start_addr, block_length);
         if (ret) {
+            error_setg(errp, "Failed to discard RAM range %s: %d", ramid, ret);
             return ret;
         }
     }
@@ -2629,11 +2633,7 @@ static int loadvm_process_command(QEMUFile *f, Error **errp)
         return loadvm_postcopy_handle_run(mis, errp);
 
     case MIG_CMD_POSTCOPY_RAM_DISCARD:
-        ret = loadvm_postcopy_ram_handle_discard(mis, len);
-        if (ret < 0) {
-            error_setg(errp, "Failed to load device state command: %d", ret);
-        }
-        return ret;
+        return loadvm_postcopy_ram_handle_discard(mis, len, errp);
 
     case MIG_CMD_POSTCOPY_RESUME:
         loadvm_postcopy_handle_resume(mis);

-- 
2.50.1
Re: [PATCH v9 18/27] migration: push Error **errp into loadvm_postcopy_ram_handle_discard()
Posted by Marc-André Lureau 4 months, 1 week ago
Hi

On Tue, Aug 5, 2025 at 10:30 PM Arun Menon <armenon@redhat.com> wrote:

> This is an incremental step in converting vmstate loading
> code to report error via Error objects instead of directly
> printing it to console/monitor.
> It is ensured that loadvm_postcopy_ram_handle_discard() must report an
> error
> in errp, in case of failure.
>
> Signed-off-by: Arun Menon <armenon@redhat.com>
>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>


> ---
>  migration/savevm.c | 26 +++++++++++++-------------
>  1 file changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/migration/savevm.c b/migration/savevm.c
> index
> eb90873a750ded354b3db31cba40b44d1be79864..3abe4193e02aae9c813ff07fb388a7ee470c8a6a
> 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -2004,7 +2004,7 @@ static int
> loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
>   * There can be 0..many of these messages, each encoding multiple pages.
>   */
>  static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> -                                              uint16_t len)
> +                                              uint16_t len, Error **errp)
>  {
>      int tmp;
>      char ramid[256];
> @@ -2017,6 +2017,7 @@ static int
> loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
>          /* 1st discard */
>          tmp = postcopy_ram_prepare_discard(mis);
>          if (tmp) {
> +            error_setg(errp, "Failed to prepare for RAM discard: %d",
> tmp);
>              return tmp;
>          }
>          break;
> @@ -2026,8 +2027,9 @@ static int
> loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
>          break;
>
>      default:
> -        error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state
> (%d)",
> -                     ps);
> +        error_setg(errp,
> +                   "CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state
> (%d)",
> +                   ps);
>          return -1;
>      }
>      /* We're expecting a
> @@ -2036,29 +2038,30 @@ static int
> loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
>       *    then at least 1 16 byte chunk
>      */
>      if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
> -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
> +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)",
> len);
>          return -1;
>      }
>
>      tmp = qemu_get_byte(mis->from_src_file);
>      if (tmp != postcopy_ram_discard_version) {
> -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)",
> tmp);
> +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid version (%d)",
> tmp);
>          return -1;
>      }
>
>      if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
> -        error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock
> ID");
> +        error_setg(errp,
> +                   "CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
>          return -1;
>      }
>      tmp = qemu_get_byte(mis->from_src_file);
>      if (tmp != 0) {
> -        error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
> +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD missing nil (%d)",
> tmp);
>          return -1;
>      }
>
>      len -= 3 + strlen(ramid);
>      if (len % 16) {
> -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
> +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)",
> len);
>          return -1;
>      }
>      trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
> @@ -2070,6 +2073,7 @@ static int
> loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
>          len -= 16;
>          int ret = ram_discard_range(ramid, start_addr, block_length);
>          if (ret) {
> +            error_setg(errp, "Failed to discard RAM range %s: %d", ramid,
> ret);
>

note: the ram_discard_range() and ram_block_discard_range() functions also
calls error_report()  Maybe they can be converted too.., let's not do this
in this already long series.




>              return ret;
>          }
>      }
> @@ -2629,11 +2633,7 @@ static int loadvm_process_command(QEMUFile *f,
> Error **errp)
>          return loadvm_postcopy_handle_run(mis, errp);
>
>      case MIG_CMD_POSTCOPY_RAM_DISCARD:
> -        ret = loadvm_postcopy_ram_handle_discard(mis, len);
> -        if (ret < 0) {
> -            error_setg(errp, "Failed to load device state command: %d",
> ret);
> -        }
> -        return ret;
> +        return loadvm_postcopy_ram_handle_discard(mis, len, errp);
>
>      case MIG_CMD_POSTCOPY_RESUME:
>          loadvm_postcopy_handle_resume(mis);
>
> --
> 2.50.1
>
>
Re: [PATCH v9 18/27] migration: push Error **errp into loadvm_postcopy_ram_handle_discard()
Posted by Arun Menon 4 months, 1 week ago
Hi Marc-André,

Thank you for the review.

On Wed, Aug 06, 2025 at 11:54:36AM +0400, Marc-André Lureau wrote:
> Hi
> 
> On Tue, Aug 5, 2025 at 10:30 PM Arun Menon <armenon@redhat.com> wrote:
> 
> > This is an incremental step in converting vmstate loading
> > code to report error via Error objects instead of directly
> > printing it to console/monitor.
> > It is ensured that loadvm_postcopy_ram_handle_discard() must report an
> > error
> > in errp, in case of failure.
> >
> > Signed-off-by: Arun Menon <armenon@redhat.com>
> >
> 
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> 
> > ---
> >  migration/savevm.c | 26 +++++++++++++-------------
> >  1 file changed, 13 insertions(+), 13 deletions(-)
> >
> > diff --git a/migration/savevm.c b/migration/savevm.c
> > index
> > eb90873a750ded354b3db31cba40b44d1be79864..3abe4193e02aae9c813ff07fb388a7ee470c8a6a
> > 100644
> > --- a/migration/savevm.c
> > +++ b/migration/savevm.c
> > @@ -2004,7 +2004,7 @@ static int
> > loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
> >   * There can be 0..many of these messages, each encoding multiple pages.
> >   */
> >  static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> > -                                              uint16_t len)
> > +                                              uint16_t len, Error **errp)
> >  {
> >      int tmp;
> >      char ramid[256];
> > @@ -2017,6 +2017,7 @@ static int
> > loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> >          /* 1st discard */
> >          tmp = postcopy_ram_prepare_discard(mis);
> >          if (tmp) {
> > +            error_setg(errp, "Failed to prepare for RAM discard: %d",
> > tmp);
> >              return tmp;
> >          }
> >          break;
> > @@ -2026,8 +2027,9 @@ static int
> > loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> >          break;
> >
> >      default:
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state
> > (%d)",
> > -                     ps);
> > +        error_setg(errp,
> > +                   "CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state
> > (%d)",
> > +                   ps);
> >          return -1;
> >      }
> >      /* We're expecting a
> > @@ -2036,29 +2038,30 @@ static int
> > loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> >       *    then at least 1 16 byte chunk
> >      */
> >      if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
> > +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)",
> > len);
> >          return -1;
> >      }
> >
> >      tmp = qemu_get_byte(mis->from_src_file);
> >      if (tmp != postcopy_ram_discard_version) {
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)",
> > tmp);
> > +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid version (%d)",
> > tmp);
> >          return -1;
> >      }
> >
> >      if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock
> > ID");
> > +        error_setg(errp,
> > +                   "CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
> >          return -1;
> >      }
> >      tmp = qemu_get_byte(mis->from_src_file);
> >      if (tmp != 0) {
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
> > +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD missing nil (%d)",
> > tmp);
> >          return -1;
> >      }
> >
> >      len -= 3 + strlen(ramid);
> >      if (len % 16) {
> > -        error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
> > +        error_setg(errp, "CMD_POSTCOPY_RAM_DISCARD invalid length (%d)",
> > len);
> >          return -1;
> >      }
> >      trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
> > @@ -2070,6 +2073,7 @@ static int
> > loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
> >          len -= 16;
> >          int ret = ram_discard_range(ramid, start_addr, block_length);
> >          if (ret) {
> > +            error_setg(errp, "Failed to discard RAM range %s: %d", ramid,
> > ret);
> >
> 
> note: the ram_discard_range() and ram_block_discard_range() functions also
> calls error_report()  Maybe they can be converted too.., let's not do this
> in this already long series.

Agreed.

> 
> 
> 
> 
> >              return ret;
> >          }
> >      }
> > @@ -2629,11 +2633,7 @@ static int loadvm_process_command(QEMUFile *f,
> > Error **errp)
> >          return loadvm_postcopy_handle_run(mis, errp);
> >
> >      case MIG_CMD_POSTCOPY_RAM_DISCARD:
> > -        ret = loadvm_postcopy_ram_handle_discard(mis, len);
> > -        if (ret < 0) {
> > -            error_setg(errp, "Failed to load device state command: %d",
> > ret);
> > -        }
> > -        return ret;
> > +        return loadvm_postcopy_ram_handle_discard(mis, len, errp);
> >
> >      case MIG_CMD_POSTCOPY_RESUME:
> >          loadvm_postcopy_handle_resume(mis);
> >
> > --
> > 2.50.1
> >
> >

Regards,
Arun